<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.boozallen.com/role/AccountsPayableAndOtherAccruedExpenses" xlink:href="bah-20170331.xsd#AccountsPayableAndOtherAccruedExpenses" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccountsPayableAndOtherAccruedExpensesDetails" xlink:href="bah-20170331.xsd#AccountsPayableAndOtherAccruedExpensesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccountsPayableAndOtherAccruedExpensesTables" xlink:href="bah-20170331.xsd#AccountsPayableAndOtherAccruedExpensesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccountsReceivableNet" xlink:href="bah-20170331.xsd#AccountsReceivableNet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccountsReceivableNetDetails" xlink:href="bah-20170331.xsd#AccountsReceivableNetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccountsReceivableNetTables" xlink:href="bah-20170331.xsd#AccountsReceivableNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccruedCompensationAndBenefits" xlink:href="bah-20170331.xsd#AccruedCompensationAndBenefits" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccruedCompensationAndBenefitsDetails" xlink:href="bah-20170331.xsd#AccruedCompensationAndBenefitsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccruedCompensationAndBenefitsTables" xlink:href="bah-20170331.xsd#AccruedCompensationAndBenefitsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossDetails" xlink:href="bah-20170331.xsd#AccumulatedOtherComprehensiveLossDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossNotes" xlink:href="bah-20170331.xsd#AccumulatedOtherComprehensiveLossNotes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossReclassificationsOutOfAccumulatedOtherComprehensiveLossToNetIncomeDetails" xlink:href="bah-20170331.xsd#AccumulatedOtherComprehensiveLossReclassificationsOutOfAccumulatedOtherComprehensiveLossToNetIncomeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossTables" xlink:href="bah-20170331.xsd#AccumulatedOtherComprehensiveLossTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/Acquisition" xlink:href="bah-20170331.xsd#Acquisition" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AcquisitionNarrativeDetails" xlink:href="bah-20170331.xsd#AcquisitionNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AcquisitionScheduleOfConsiderationTransferredDetails" xlink:href="bah-20170331.xsd#AcquisitionScheduleOfConsiderationTransferredDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AcquisitionScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:href="bah-20170331.xsd#AcquisitionScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/AcquisitionTables" xlink:href="bah-20170331.xsd#AcquisitionTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/BusinessOverview" xlink:href="bah-20170331.xsd#BusinessOverview" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/BusinessOverviewDetails" xlink:href="bah-20170331.xsd#BusinessOverviewDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/BusinessSegmentInformation" xlink:href="bah-20170331.xsd#BusinessSegmentInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/BusinessSegmentInformationDetails" xlink:href="bah-20170331.xsd#BusinessSegmentInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/CommitmentsAndContingeciesDetails" xlink:href="bah-20170331.xsd#CommitmentsAndContingeciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/CommitmentsAndContingencies" xlink:href="bah-20170331.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/CommitmentsAndContingenciesLitigationDetails" xlink:href="bah-20170331.xsd#CommitmentsAndContingenciesLitigationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/CommitmentsAndContingenciesTables" xlink:href="bah-20170331.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/ConsolidatedBalanceSheets" xlink:href="bah-20170331.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="bah-20170331.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="bah-20170331.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="bah-20170331.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/ConsolidatedStatementsOfOperations" xlink:href="bah-20170331.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/ConsolidatedStatementsOfStockholdersEquityStatement" xlink:href="bah-20170331.xsd#ConsolidatedStatementsOfStockholdersEquityStatement" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/Debt" xlink:href="bah-20170331.xsd#Debt" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DebtDebtDetailOfInterestExpenseDetails" xlink:href="bah-20170331.xsd#DebtDebtDetailOfInterestExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DebtDetails" xlink:href="bah-20170331.xsd#DebtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DebtFutureDebtPrincipalRepaymentsDetails" xlink:href="bah-20170331.xsd#DebtFutureDebtPrincipalRepaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DebtScheduleOfDebtDetails" xlink:href="bah-20170331.xsd#DebtScheduleOfDebtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DebtTables" xlink:href="bah-20170331.xsd#DebtTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DeferredPaymentObligation" xlink:href="bah-20170331.xsd#DeferredPaymentObligation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DeferredPaymentObligationDetails" xlink:href="bah-20170331.xsd#DeferredPaymentObligationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DeferredPaymentObligationTables" xlink:href="bah-20170331.xsd#DeferredPaymentObligationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/DocumentAndEntityInformation" xlink:href="bah-20170331.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EarningsPerShare" xlink:href="bah-20170331.xsd#EarningsPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EarningsPerShareDetails" xlink:href="bah-20170331.xsd#EarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EarningsPerShareTables" xlink:href="bah-20170331.xsd#EarningsPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlans" xlink:href="bah-20170331.xsd#EmployeeBenefitPlans" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansAccumulatedOtherComprehensiveIncomeDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansAdditionalInformationDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansChangeInBenefitObligationAndChangeInPlanAssetsDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansChangeInBenefitObligationAndChangeInPlanAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansComponentsOfNetPostretirementMedicalExpenseDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansComponentsOfNetPostretirementMedicalExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansFutureBenefitPaymentsDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansFutureBenefitPaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansHealthcareCostTrendRatesDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansHealthcareCostTrendRatesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansRetiredOfficersBonusPlanAndRetiredVpBonusPlanDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansRetiredOfficersBonusPlanAndRetiredVpBonusPlanDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansTables" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/EmployeeBenefitPlansWeightedAverageDiscountRateDetails" xlink:href="bah-20170331.xsd#EmployeeBenefitPlansWeightedAverageDiscountRateDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/FairValueMeasurements" xlink:href="bah-20170331.xsd#FairValueMeasurements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/FairValueMeasurementsFairValueMeasurementsLevel3RollforwardDetails" xlink:href="bah-20170331.xsd#FairValueMeasurementsFairValueMeasurementsLevel3RollforwardDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/FairValueMeasurementsRecurringFairValueMeasurementsDetails" xlink:href="bah-20170331.xsd#FairValueMeasurementsRecurringFairValueMeasurementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/FairValueMeasurementsTables" xlink:href="bah-20170331.xsd#FairValueMeasurementsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/GoodwillAndIntangibleAssets" xlink:href="bah-20170331.xsd#GoodwillAndIntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsExpectedAmortizationExpenseDetails" xlink:href="bah-20170331.xsd#GoodwillAndIntangibleAssetsExpectedAmortizationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsFiniteLivedIntangibleAssetsDetails" xlink:href="bah-20170331.xsd#GoodwillAndIntangibleAssetsFiniteLivedIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsGoodwillDetails" xlink:href="bah-20170331.xsd#GoodwillAndIntangibleAssetsGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsTables" xlink:href="bah-20170331.xsd#GoodwillAndIntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/GoodwillAndIntangilbeAssetsIndefiniteLivedIntangibleAssetsDetails" xlink:href="bah-20170331.xsd#GoodwillAndIntangilbeAssetsIndefiniteLivedIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/IncomeTaxesComponentsOfIncomeTaxesDetails" xlink:href="bah-20170331.xsd#IncomeTaxesComponentsOfIncomeTaxesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/IncomeTaxesComponentsOfNetDeferredIncomeTaxesDetails" xlink:href="bah-20170331.xsd#IncomeTaxesComponentsOfNetDeferredIncomeTaxesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/IncomeTaxesIncomeTaxes" xlink:href="bah-20170331.xsd#IncomeTaxesIncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/IncomeTaxesReconciliationOfIncomeTaxDetails" xlink:href="bah-20170331.xsd#IncomeTaxesReconciliationOfIncomeTaxDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/IncomeTaxesTables" xlink:href="bah-20170331.xsd#IncomeTaxesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/IncomeTaxesUncertainTaxPositionsDetails" xlink:href="bah-20170331.xsd#IncomeTaxesUncertainTaxPositionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/OtherLongTermLiabilities" xlink:href="bah-20170331.xsd#OtherLongTermLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/OtherLongTermLiabilitiesDetails" xlink:href="bah-20170331.xsd#OtherLongTermLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/OtherLongTermLiabilitiesTables" xlink:href="bah-20170331.xsd#OtherLongTermLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/PropertyAndEquipmentNet" xlink:href="bah-20170331.xsd#PropertyAndEquipmentNet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/PropertyAndEquipmentNetDetails" xlink:href="bah-20170331.xsd#PropertyAndEquipmentNetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/PropertyAndEquipmentNetTables" xlink:href="bah-20170331.xsd#PropertyAndEquipmentNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/RelatedPartyTransactions" xlink:href="bah-20170331.xsd#RelatedPartyTransactions" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/RelatedPartyTransactionsDetails" xlink:href="bah-20170331.xsd#RelatedPartyTransactionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensation" xlink:href="bah-20170331.xsd#StockBasedCompensation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationSpecialDividendsDetails" xlink:href="bah-20170331.xsd#StockBasedCompensationSpecialDividendsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationStockBasedCompensationExpenseDetails" xlink:href="bah-20170331.xsd#StockBasedCompensationStockBasedCompensationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationStockOptionAndRestrictedStockAwardActivityDetails" xlink:href="bah-20170331.xsd#StockBasedCompensationStockOptionAndRestrictedStockAwardActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationStockOptionAssumptionsDetails" xlink:href="bah-20170331.xsd#StockBasedCompensationStockOptionAssumptionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationStockPlansDetails" xlink:href="bah-20170331.xsd#StockBasedCompensationStockPlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationTables" xlink:href="bah-20170331.xsd#StockBasedCompensationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockBasedCompensationUnrecognizedCompensationDetails" xlink:href="bah-20170331.xsd#StockBasedCompensationUnrecognizedCompensationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockholdersEquity" xlink:href="bah-20170331.xsd#StockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockholdersEquityCommonStockSharesActivityDetails" xlink:href="bah-20170331.xsd#StockholdersEquityCommonStockSharesActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockholdersEquityDividendsDetails" xlink:href="bah-20170331.xsd#StockholdersEquityDividendsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockholdersEquityEmployeeStockPurchasePlanAndShareRepurchaseProgramDetails" xlink:href="bah-20170331.xsd#StockholdersEquityEmployeeStockPurchasePlanAndShareRepurchaseProgramDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/StockholdersEquityTables" xlink:href="bah-20170331.xsd#StockholdersEquityTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SubsequentEvents" xlink:href="bah-20170331.xsd#SubsequentEvents" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SubsequentEventsNarrativeDetails" xlink:href="bah-20170331.xsd#SubsequentEventsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SummaryOfSignificantAccountingPolicies" xlink:href="bah-20170331.xsd#SummaryOfSignificantAccountingPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SummaryOfSignificantAccountingPoliciesIntangibleAssetsDetails" xlink:href="bah-20170331.xsd#SummaryOfSignificantAccountingPoliciesIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:href="bah-20170331.xsd#SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SummaryOfSignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" xlink:href="bah-20170331.xsd#SummaryOfSignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SupplementalFinancialInformation" xlink:href="bah-20170331.xsd#SupplementalFinancialInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SupplementalFinancialInformationDetails" xlink:href="bah-20170331.xsd#SupplementalFinancialInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/SupplementalFinancialInformationTables" xlink:href="bah-20170331.xsd#SupplementalFinancialInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/UnauditedQuarterlyFinancialData" xlink:href="bah-20170331.xsd#UnauditedQuarterlyFinancialData" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/UnauditedQuarterlyFinancialDataDetails" xlink:href="bah-20170331.xsd#UnauditedQuarterlyFinancialDataDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.boozallen.com/role/UnauditedQuarterlyFinancialDataTables" xlink:href="bah-20170331.xsd#UnauditedQuarterlyFinancialDataTables" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccountsPayableAndOtherAccruedExpenses" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccountsPayableAndOtherAccruedExpensesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccountsPayableAndOtherAccruedExpensesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccountsReceivableNet" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccountsReceivableNetDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_0991D4DC5484AC1EFBF24B37DDD0FACD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_0991D4DC5484AC1EFBF24B37DDD0FACD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_A17B64A0A41B00E64A894B37DDD09D24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_0991D4DC5484AC1EFBF24B37DDD0FACD" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_A17B64A0A41B00E64A894B37DDD09D24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_DFE0FC270BE3E61650EB4B37DDD075F4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_A17B64A0A41B00E64A894B37DDD09D24" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_DFE0FC270BE3E61650EB4B37DDD075F4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_DFE0FC270BE3E61650EB4B37DDD075F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_A17B64A0A41B00E64A894B37DDD09D24" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_DFE0FC270BE3E61650EB4B37DDD075F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsReceivableMember" xlink:label="loc_us-gaap_AccountsReceivableMember_61E3F28752199BAE32F84B37DDD0F3FE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_DFE0FC270BE3E61650EB4B37DDD075F4" xlink:to="loc_us-gaap_AccountsReceivableMember_61E3F28752199BAE32F84B37DDD0F3FE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherNoncurrentAssetsMember" xlink:label="loc_us-gaap_OtherNoncurrentAssetsMember_3A32BEAD61C744E5730C4B37DDD05F6F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_DFE0FC270BE3E61650EB4B37DDD075F4" xlink:to="loc_us-gaap_OtherNoncurrentAssetsMember_3A32BEAD61C744E5730C4B37DDD05F6F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BilledContractReceivables" xlink:label="loc_us-gaap_BilledContractReceivables_10BC5DB24BE14A1849B74B37DDD09E26" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_BilledContractReceivables_10BC5DB24BE14A1849B74B37DDD09E26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UnbilledContractsReceivable" xlink:label="loc_us-gaap_UnbilledContractsReceivable_CB62EA9B2A0ABDF651794B37DDD21052" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_UnbilledContractsReceivable_CB62EA9B2A0ABDF651794B37DDD21052" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_D158601243384ED354094B37DDD21D37" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_D158601243384ED354094B37DDD21D37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_81D0AD3CD859AAA925BF4B37DDD244BA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_81D0AD3CD859AAA925BF4B37DDD244BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsReceivableNet" xlink:label="loc_us-gaap_AccountsReceivableNet_A0F63BC92F9D4EDF1DC64B37DDD228F8" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_AccountsReceivableNet_A0F63BC92F9D4EDF1DC64B37DDD228F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_7611F113F529D16B33FB4B37DDD2DB85" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_EC865A0B998DD00310834B37DDD0D470" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_7611F113F529D16B33FB4B37DDD2DB85" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccountsReceivableNetTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccruedCompensationAndBenefits" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccruedCompensationAndBenefitsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccruedCompensationAndBenefitsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossNotes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossReclassificationsOutOfAccumulatedOtherComprehensiveLossToNetIncomeDetails" xlink:type="extended">
    <link:loc xlink:href="bah-20170331.xsd#bah_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeLineItems" xlink:label="loc_bah_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeLineItems_8E920EB61BFF4E80BABBECCE2F1D0AF9" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F66389E45BBCF5A14C05ECCE2F1C926A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_bah_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeLineItems_8E920EB61BFF4E80BABBECCE2F1D0AF9" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F66389E45BBCF5A14C05ECCE2F1C926A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_EB6661B5970D438F9A2AECCE2F1C2014" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F66389E45BBCF5A14C05ECCE2F1C926A" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_EB6661B5970D438F9A2AECCE2F1C2014" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_62E803FEA207FB917C41ECCE2F1C27E5_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_EB6661B5970D438F9A2AECCE2F1C2014" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_62E803FEA207FB917C41ECCE2F1C27E5_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_62E803FEA207FB917C41ECCE2F1C27E5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_EB6661B5970D438F9A2AECCE2F1C2014" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_62E803FEA207FB917C41ECCE2F1C27E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_D8CB207B90C57228E135ECCE2F1CC5EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_62E803FEA207FB917C41ECCE2F1C27E5" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_D8CB207B90C57228E135ECCE2F1CC5EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_985B8E7D9C198D9AB81DECCE2F1C714C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_F66389E45BBCF5A14C05ECCE2F1C926A" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_985B8E7D9C198D9AB81DECCE2F1C714C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_8D355D4AC8AF57907A22ECCE2F1C7E2F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_985B8E7D9C198D9AB81DECCE2F1C714C" xlink:to="loc_us-gaap_EquityComponentDomain_8D355D4AC8AF57907A22ECCE2F1C7E2F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_8D355D4AC8AF57907A22ECCE2F1C7E2F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_985B8E7D9C198D9AB81DECCE2F1C714C" xlink:to="loc_us-gaap_EquityComponentDomain_8D355D4AC8AF57907A22ECCE2F1C7E2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_9D5BB1CBB94E9D4A54C0ECCE2F1DC92F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_8D355D4AC8AF57907A22ECCE2F1C7E2F" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_9D5BB1CBB94E9D4A54C0ECCE2F1DC92F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax_F67D8BFBC3E9D55B1A0DECCE2F1D0BAB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeLineItems_8E920EB61BFF4E80BABBECCE2F1D0AF9" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax_F67D8BFBC3E9D55B1A0DECCE2F1D0BAB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_8C7C8D010DB4F871A8B0ECCE2F1D7482" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeLineItems_8E920EB61BFF4E80BABBECCE2F1D0AF9" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_8C7C8D010DB4F871A8B0ECCE2F1D7482" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_EFFA268467236AF11954ECCE2F1D953D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeLineItems_8E920EB61BFF4E80BABBECCE2F1D0AF9" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_EFFA268467236AF11954ECCE2F1D953D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AccumulatedOtherComprehensiveLossTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/Acquisition" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AcquisitionNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_FD42805F0501F6B20A802D48CB08459D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_FD42805F0501F6B20A802D48CB08459D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_59A309CFA449981450A52D48CB08C0A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_FD42805F0501F6B20A802D48CB08459D" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_59A309CFA449981450A52D48CB08C0A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5CB770E891C5432857782D48CB08C041_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_59A309CFA449981450A52D48CB08C0A4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5CB770E891C5432857782D48CB08C041_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5CB770E891C5432857782D48CB08C041" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_59A309CFA449981450A52D48CB08C0A4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5CB770E891C5432857782D48CB08C041" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_56A8026B5BF1D76EB7B22D48CB08EDC5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5CB770E891C5432857782D48CB08C041" xlink:to="loc_us-gaap_CustomerRelationshipsMember_56A8026B5BF1D76EB7B22D48CB08EDC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_FAECF82A77FF0CC00B9D2D48CB0926DE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_FD42805F0501F6B20A802D48CB08459D" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_FAECF82A77FF0CC00B9D2D48CB0926DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_9755108F4568F4256FF12D48CB09CD12_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_FAECF82A77FF0CC00B9D2D48CB0926DE" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_9755108F4568F4256FF12D48CB09CD12_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_9755108F4568F4256FF12D48CB09CD12" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_FAECF82A77FF0CC00B9D2D48CB0926DE" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_9755108F4568F4256FF12D48CB09CD12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_1535782919058B9563962D48CB0996C5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_9755108F4568F4256FF12D48CB09CD12" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_1535782919058B9563962D48CB0996C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_CCB53BE9886BF49E3E1E2D48CB091A56" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_FD42805F0501F6B20A802D48CB08459D" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_CCB53BE9886BF49E3E1E2D48CB091A56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DE10EE027103F51BEF482D48CB09BDAA_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_CCB53BE9886BF49E3E1E2D48CB091A56" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DE10EE027103F51BEF482D48CB09BDAA_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DE10EE027103F51BEF482D48CB09BDAA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_CCB53BE9886BF49E3E1E2D48CB091A56" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DE10EE027103F51BEF482D48CB09BDAA" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_EGovHoldingsInc.dbaAquilentMember" xlink:label="loc_bah_EGovHoldingsInc.dbaAquilentMember_F1407799C6B34375E1752D48CB09223B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_DE10EE027103F51BEF482D48CB09BDAA" xlink:to="loc_bah_EGovHoldingsInc.dbaAquilentMember_F1407799C6B34375E1752D48CB09223B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_D8CCBBA6FD612BBC51502D48CB0AAFEA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_D8CCBBA6FD612BBC51502D48CB0AAFEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:label="loc_us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_4F59E392D02A08F595932D48CB0AA145" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_4F59E392D02A08F595932D48CB0AA145" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_68ABAEF12C9FBACEF08D2D48CB0A8B1B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_68ABAEF12C9FBACEF08D2D48CB0A8B1B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_A830BD1F8100431AB63F2D48CB0A938E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_A830BD1F8100431AB63F2D48CB0A938E" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_BusinessCombinationTaxIndemnificationLiability" xlink:label="loc_bah_BusinessCombinationTaxIndemnificationLiability_2021E0C34C1974CE35822D48CB0A1546" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_bah_BusinessCombinationTaxIndemnificationLiability_2021E0C34C1974CE35822D48CB0A1546" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_B4C77B61A0262B686EC72D48CB0AA688" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_B4C77B61A0262B686EC72D48CB0AA688" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_619B1BB4F59D6D4358F12D48CB0A0F2C" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_E965F45D68222650273B2D48CB0918DF" xlink:to="loc_us-gaap_Goodwill_619B1BB4F59D6D4358F12D48CB0A0F2C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AcquisitionScheduleOfConsiderationTransferredDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_667D25D84217B6DBF0A3307FE62629BC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_667D25D84217B6DBF0A3307FE62629BC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_33955CC10045B6600878307FE6262918" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_667D25D84217B6DBF0A3307FE62629BC" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_33955CC10045B6600878307FE6262918" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1E8B02EF190C1457E907307FE626740D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_33955CC10045B6600878307FE6262918" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1E8B02EF190C1457E907307FE626740D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1E8B02EF190C1457E907307FE626740D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_33955CC10045B6600878307FE6262918" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1E8B02EF190C1457E907307FE626740D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_EGovHoldingsInc.dbaAquilentMember" xlink:label="loc_bah_EGovHoldingsInc.dbaAquilentMember_C12C6584D762E838DA49307FE6263E9F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1E8B02EF190C1457E907307FE626740D" xlink:to="loc_bah_EGovHoldingsInc.dbaAquilentMember_C12C6584D762E838DA49307FE6263E9F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_18FD4D49344F086C508F307FE6263856" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_18FD4D49344F086C508F307FE6263856" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_7CEA781D1AAC54636C2E307FE6263047" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred_7CEA781D1AAC54636C2E307FE6263047" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAcquiredFromAcquisition" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_5C76B6EB0FBA8FE1F63A307FE626D8AB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_5C76B6EB0FBA8FE1F63A307FE626D8AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_4371552645F516CA6B50307FE626D9FD" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed_4371552645F516CA6B50307FE626D9FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_3B2FDC0CC401FB748898307FE626A361" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_3B2FDC0CC401FB748898307FE626A361" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_E27BAA94DE50C685B850307FE626D0D8" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_6A4C08BBA04AEA2A03C4307FE62614EA" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_E27BAA94DE50C685B850307FE626D0D8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AcquisitionScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_B604E15FAAB2FB55BE562D48CCA69FB0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9770C9B0371FEA5E00D42D48CCA61EF4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B604E15FAAB2FB55BE562D48CCA69FB0" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9770C9B0371FEA5E00D42D48CCA61EF4" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7D0AED1252939175F2002D48CCA66DB2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9770C9B0371FEA5E00D42D48CCA61EF4" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7D0AED1252939175F2002D48CCA66DB2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EA039F2602AE9BEA22202D48CCA6027D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7D0AED1252939175F2002D48CCA66DB2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EA039F2602AE9BEA22202D48CCA6027D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EA039F2602AE9BEA22202D48CCA6027D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7D0AED1252939175F2002D48CCA66DB2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EA039F2602AE9BEA22202D48CCA6027D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_EGovHoldingsInc.dbaAquilentMember" xlink:label="loc_bah_EGovHoldingsInc.dbaAquilentMember_CD6DD6E93511337575692D48CCA6E4AD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EA039F2602AE9BEA22202D48CCA6027D" xlink:to="loc_bah_EGovHoldingsInc.dbaAquilentMember_CD6DD6E93511337575692D48CCA6E4AD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_B604E15FAAB2FB55BE562D48CCA69FB0" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_534200D3553F773C99D02D48CCA8011E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_534200D3553F773C99D02D48CCA8011E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_5E5E4D60653EAB0C51B82D48CCA834CD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_5E5E4D60653EAB0C51B82D48CCA834CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_22E748D6A43AF176D9D32D48CCA89957" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_22E748D6A43AF176D9D32D48CCA89957" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_2DB1C62731BD36253C702D48CCA8B23C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_Goodwill_2DB1C62731BD36253C702D48CCA8B23C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_E5989629F692EB980ED92D48CCA96B9B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_E5989629F692EB980ED92D48CCA96B9B" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_BusinessCombinationTaxIndemnificationLiability" xlink:label="loc_bah_BusinessCombinationTaxIndemnificationLiability_D9CE403A08EF6686577D2D48CCA985D3" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_bah_BusinessCombinationTaxIndemnificationLiability_D9CE403A08EF6686577D2D48CCA985D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_1E826763C1BA34EED3FD2D48CCA9B353" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_1E826763C1BA34EED3FD2D48CCA9B353" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_A68F9645E6C0BA32F2132D48CCA9A043" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_7429FEAA2694DB5C24932D48CCA7E9F5" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_A68F9645E6C0BA32F2132D48CCA9A043" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/AcquisitionTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/BusinessOverview" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/BusinessOverviewDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/BusinessSegmentInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/BusinessSegmentInformationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/CommitmentsAndContingeciesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="loc_us-gaap_ConcentrationRiskTable_580D03E6872B318A3AFB1C26F16EABCD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:to="loc_us-gaap_ConcentrationRiskTable_580D03E6872B318A3AFB1C26F16EABCD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GuaranteeObligationsByNatureAxis" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_6A53377528B60197C7BC1C26F16ED3D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_580D03E6872B318A3AFB1C26F16EABCD" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_6A53377528B60197C7BC1C26F16ED3D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_A7670F3E4500307143DE1C26F16E8876_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_6A53377528B60197C7BC1C26F16ED3D3" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_A7670F3E4500307143DE1C26F16E8876_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_A7670F3E4500307143DE1C26F16E8876" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_6A53377528B60197C7BC1C26F16ED3D3" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_A7670F3E4500307143DE1C26F16E8876" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FinancialStandbyLetterOfCreditMember" xlink:label="loc_us-gaap_FinancialStandbyLetterOfCreditMember_F6222DAD9D42FB8E20BF1C26F16E4C3B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_A7670F3E4500307143DE1C26F16E8876" xlink:to="loc_us-gaap_FinancialStandbyLetterOfCreditMember_F6222DAD9D42FB8E20BF1C26F16E4C3B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_585D018509068CFD7A8E1C26F16E8CDD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_580D03E6872B318A3AFB1C26F16EABCD" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_585D018509068CFD7A8E1C26F16E8CDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_D48774087F0F2261FEAC1C26F16EFE42_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_585D018509068CFD7A8E1C26F16E8CDD" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_D48774087F0F2261FEAC1C26F16EFE42_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_D48774087F0F2261FEAC1C26F16EFE42" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_585D018509068CFD7A8E1C26F16E8CDD" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_D48774087F0F2261FEAC1C26F16EFE42" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GovernmentContractsConcentrationRiskMember" xlink:label="loc_us-gaap_GovernmentContractsConcentrationRiskMember_11A50288139EA450B3FB1C26F16EB466" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_D48774087F0F2261FEAC1C26F16EFE42" xlink:to="loc_us-gaap_GovernmentContractsConcentrationRiskMember_11A50288139EA450B3FB1C26F16EB466" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_51447D4BBD706C74265B1C26F16ECE5B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_51447D4BBD706C74265B1C26F16ECE5B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GuaranteeObligationsLiquidationProceeds" xlink:label="loc_us-gaap_GuaranteeObligationsLiquidationProceeds_635737B68AD3710D26071C26F16E4163" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:to="loc_us-gaap_GuaranteeObligationsLiquidationProceeds_635737B68AD3710D26071C26F16E4163" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_GuarantorObligationsFacility" xlink:label="loc_bah_GuarantorObligationsFacility_62FAF3BA8A6F8DC472E71C26F16EC793" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:to="loc_bah_GuarantorObligationsFacility_62FAF3BA8A6F8DC472E71C26F16EC793" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_GuarantorObligationsAvailableAmount" xlink:label="loc_bah_GuarantorObligationsAvailableAmount_9C93CF1D81C287D4B0C11C26F16EB6A9" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:to="loc_bah_GuarantorObligationsAvailableAmount_9C93CF1D81C287D4B0C11C26F16EB6A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_EEFD402B3C99688A3B321C26F16E79C4" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1AAE82B70D76051AD7021C26F16E9C98" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_EEFD402B3C99688A3B321C26F16E79C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_2F5E173ECB27427314941C26F16F4E7D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_0F509C469C77B2E9466E1C26F16E2669" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_2F5E173ECB27427314941C26F16F4E7D" xlink:to="loc_us-gaap_LossContingenciesTable_0F509C469C77B2E9466E1C26F16E2669" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_8250EC498E6E0FE6551A1C26F16E947E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_0F509C469C77B2E9466E1C26F16E2669" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_8250EC498E6E0FE6551A1C26F16E947E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_ACFC8CF1C84B1C0029F31C26F16F4E6F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_8250EC498E6E0FE6551A1C26F16E947E" xlink:to="loc_us-gaap_LossContingencyNatureDomain_ACFC8CF1C84B1C0029F31C26F16F4E6F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_ACFC8CF1C84B1C0029F31C26F16F4E6F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_8250EC498E6E0FE6551A1C26F16E947E" xlink:to="loc_us-gaap_LossContingencyNatureDomain_ACFC8CF1C84B1C0029F31C26F16F4E6F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UnfavorableRegulatoryActionMember" xlink:label="loc_us-gaap_UnfavorableRegulatoryActionMember_E7615A7AE77F427005221C26F16F3273" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_ACFC8CF1C84B1C0029F31C26F16F4E6F" xlink:to="loc_us-gaap_UnfavorableRegulatoryActionMember_E7615A7AE77F427005221C26F16F3273" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_8758C89EB0297FF0F7DD1C26F16F1ED6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_2F5E173ECB27427314941C26F16F4E7D" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_8758C89EB0297FF0F7DD1C26F16F1ED6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/CommitmentsAndContingenciesLitigationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_70A4655D9EA6E9AE3FAB3129C2C804FE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingenciesTable_70A4655D9EA6E9AE3FAB3129C2C804FE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_271054E25BA12873B76D3129C2C8371A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_70A4655D9EA6E9AE3FAB3129C2C804FE" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_271054E25BA12873B76D3129C2C8371A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_BB345B3DE017407254C93129C2C9FC60_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_271054E25BA12873B76D3129C2C8371A" xlink:to="loc_us-gaap_LossContingencyNatureDomain_BB345B3DE017407254C93129C2C9FC60_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_BB345B3DE017407254C93129C2C9FC60" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_271054E25BA12873B76D3129C2C8371A" xlink:to="loc_us-gaap_LossContingencyNatureDomain_BB345B3DE017407254C93129C2C9FC60" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_FormerStockholderLitigationMember" xlink:label="loc_bah_FormerStockholderLitigationMember_4874B0AEBBE69D3E712C3129C2C9DEE3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_BB345B3DE017407254C93129C2C9FC60" xlink:to="loc_bah_FormerStockholderLitigationMember_4874B0AEBBE69D3E712C3129C2C9DEE3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationCaseAxis" xlink:label="loc_us-gaap_LitigationCaseAxis_C26D3CF650AB8EA0C7E73129C2C9C840" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_70A4655D9EA6E9AE3FAB3129C2C804FE" xlink:to="loc_us-gaap_LitigationCaseAxis_C26D3CF650AB8EA0C7E73129C2C9C840" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationCaseTypeDomain" xlink:label="loc_us-gaap_LitigationCaseTypeDomain_D9BD0945C46C1C8F1DA63129C2C9CEB3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationCaseAxis_C26D3CF650AB8EA0C7E73129C2C9C840" xlink:to="loc_us-gaap_LitigationCaseTypeDomain_D9BD0945C46C1C8F1DA63129C2C9CEB3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationCaseTypeDomain" xlink:label="loc_us-gaap_LitigationCaseTypeDomain_D9BD0945C46C1C8F1DA63129C2C9CEB3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationCaseAxis_C26D3CF650AB8EA0C7E73129C2C9C840" xlink:to="loc_us-gaap_LitigationCaseTypeDomain_D9BD0945C46C1C8F1DA63129C2C9CEB3" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_RacketeerInfluencedAndCorruptOrganizationsActMember" xlink:label="loc_bah_RacketeerInfluencedAndCorruptOrganizationsActMember_24015A777270F316D1BE3129C2C969DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationCaseTypeDomain_D9BD0945C46C1C8F1DA63129C2C9CEB3" xlink:to="loc_bah_RacketeerInfluencedAndCorruptOrganizationsActMember_24015A777270F316D1BE3129C2C969DC" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_LitigationCourtAxis" xlink:label="loc_bah_LitigationCourtAxis_86649F10ABF1C258EAC83129C2C90DF7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_70A4655D9EA6E9AE3FAB3129C2C804FE" xlink:to="loc_bah_LitigationCourtAxis_86649F10ABF1C258EAC83129C2C90DF7" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_LitigationCourtTypeDomain" xlink:label="loc_bah_LitigationCourtTypeDomain_A285A0444CE29112D3013129C2C91ACC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_bah_LitigationCourtAxis_86649F10ABF1C258EAC83129C2C90DF7" xlink:to="loc_bah_LitigationCourtTypeDomain_A285A0444CE29112D3013129C2C91ACC_default" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_LitigationCourtTypeDomain" xlink:label="loc_bah_LitigationCourtTypeDomain_A285A0444CE29112D3013129C2C91ACC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_bah_LitigationCourtAxis_86649F10ABF1C258EAC83129C2C90DF7" xlink:to="loc_bah_LitigationCourtTypeDomain_A285A0444CE29112D3013129C2C91ACC" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnitedStatesCourtofAppealsfortheNinthCircuitMember" xlink:label="loc_bah_UnitedStatesCourtofAppealsfortheNinthCircuitMember_5406BDFC94D976B211CD3129C2C96557" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_LitigationCourtTypeDomain_A285A0444CE29112D3013129C2C91ACC" xlink:to="loc_bah_UnitedStatesCourtofAppealsfortheNinthCircuitMember_5406BDFC94D976B211CD3129C2C96557" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnitedStatesCourtofAppealsfortheSecondCircuitMember" xlink:label="loc_bah_UnitedStatesCourtofAppealsfortheSecondCircuitMember_80DDDB71381BE04E475D312F014DF52B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_LitigationCourtTypeDomain_A285A0444CE29112D3013129C2C91ACC" xlink:to="loc_bah_UnitedStatesCourtofAppealsfortheSecondCircuitMember_80DDDB71381BE04E475D312F014DF52B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNumberOfPlaintiffs" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs_55264F1C790D995B2E313129C2CA0467" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs_55264F1C790D995B2E313129C2CA0467" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNewClaimsFiledNumber" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_57F81586CB8A796099203129C2CAE462" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_57F81586CB8A796099203129C2CAE462" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_LossContingencyClaimsAmendedNumber" xlink:label="loc_bah_LossContingencyClaimsAmendedNumber_E324B73B63E5A2055B223129C2CA3F36" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_bah_LossContingencyClaimsAmendedNumber_E324B73B63E5A2055B223129C2CA3F36" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyClaimsSettledAndDismissedNumber" xlink:label="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_BA318971C9E471B1099F3129C2CAC59B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingencyClaimsSettledAndDismissedNumber_BA318971C9E471B1099F3129C2CAC59B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyClaimsSettledNumber" xlink:label="loc_us-gaap_LossContingencyClaimsSettledNumber_0D85355E940976A2B7B43129C2CA3FA5" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingencyClaimsSettledNumber_0D85355E940976A2B7B43129C2CA3FA5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_86A39724C281CF40FB3E3129C2CACA98" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_86A39724C281CF40FB3E3129C2CACA98" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyDamagesSoughtValue" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_16F53A81DA7D67FC08BE3129C2CB8156" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_44440193561B1330843D3129C2CA2FE0" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_16F53A81DA7D67FC08BE3129C2CB8156" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/CommitmentsAndContingenciesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_82976AE5B724A1D75D8D310B4AD695FC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_D80DC3EF90E08757FF29310B4AD60067" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_82976AE5B724A1D75D8D310B4AD695FC" xlink:to="loc_us-gaap_StatementTable_D80DC3EF90E08757FF29310B4AD60067" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_8FB08E004BB7B0F82CB5310B4AD62AAC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_D80DC3EF90E08757FF29310B4AD60067" xlink:to="loc_us-gaap_StatementClassOfStockAxis_8FB08E004BB7B0F82CB5310B4AD62AAC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_8FB08E004BB7B0F82CB5310B4AD62AAC" xlink:to="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_8FB08E004BB7B0F82CB5310B4AD62AAC" xlink:to="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_216A5AB1766EDDF994F5310B4AD6ED69" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC" xlink:to="loc_us-gaap_CommonClassAMember_216A5AB1766EDDF994F5310B4AD6ED69" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_47F9EDE97614BE3E37E7310B4AD67D8F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC" xlink:to="loc_us-gaap_CommonClassBMember_47F9EDE97614BE3E37E7310B4AD67D8F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_DD13FEBE3DF175DEE0B4310B4AD60C10" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC" xlink:to="loc_us-gaap_CommonClassCMember_DD13FEBE3DF175DEE0B4310B4AD60C10" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_CommonClassEMember" xlink:label="loc_bah_CommonClassEMember_31C981DDBCB0B31B36E0310B4AD6B0A3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_463175272C7531BC7FC4310B4AD6CFCC" xlink:to="loc_bah_CommonClassEMember_31C981DDBCB0B31B36E0310B4AD6B0A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_82976AE5B724A1D75D8D310B4AD695FC" xlink:to="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_59DBD9EF28B1FCD88659310B4AD6DD2B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_AssetsCurrentAbstract_59DBD9EF28B1FCD88659310B4AD6DD2B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_D0B6D832E87C494AACE7310B4AD65E12" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_59DBD9EF28B1FCD88659310B4AD6DD2B" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_D0B6D832E87C494AACE7310B4AD65E12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_69B4EEA47163283D8E4A310B4AD68388" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_59DBD9EF28B1FCD88659310B4AD6DD2B" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_69B4EEA47163283D8E4A310B4AD68388" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_C56FCBDDA91F103E8AAF310B4AD62B4D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_59DBD9EF28B1FCD88659310B4AD6DD2B" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_C56FCBDDA91F103E8AAF310B4AD62B4D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_67A68DA2AC0FFBDA8752310B4AD693EF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_59DBD9EF28B1FCD88659310B4AD6DD2B" xlink:to="loc_us-gaap_AssetsCurrent_67A68DA2AC0FFBDA8752310B4AD693EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_D5C33DAB780AC462E907310B4AD6B025" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_D5C33DAB780AC462E907310B4AD6B025" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNetNoncurrent_DF5AD0E8D56861D86AC2310B4AD6C106" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_DeferredTaxAssetsLiabilitiesNetNoncurrent_DF5AD0E8D56861D86AC2310B4AD6C106" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_2AE5F635BEE23D64069A310B4AD69167" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_2AE5F635BEE23D64069A310B4AD69167" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_68A47B71496D5E14D038310B4AD6128A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_Goodwill_68A47B71496D5E14D038310B4AD6128A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_443C2EC4DACE1E60C9C2310B4AD6B302" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_443C2EC4DACE1E60C9C2310B4AD6B302" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_BE8E4ECD202DD9CAAACA310B4AD6A3DD" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3191E5F56A0CE378C58B310B4AD65EDD" xlink:to="loc_us-gaap_Assets_BE8E4ECD202DD9CAAACA310B4AD6A3DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_82976AE5B724A1D75D8D310B4AD695FC" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_055BB3312643D2558A53310B4AD6B47A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:to="loc_us-gaap_LongTermDebtCurrent_055BB3312643D2558A53310B4AD6B47A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_FA1AD8CAD844A97B87FA310B4AD691BD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_FA1AD8CAD844A97B87FA310B4AD691BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_5C20515E01EA9AFF7F2B310B4AD6C09B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_5C20515E01EA9AFF7F2B310B4AD6C09B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_5698DE6C86C34CCA827A310B4AD6E16F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_5698DE6C86C34CCA827A310B4AD6E16F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_8FFAEE7AA679E0F74B52310B4AD68384" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_3F58C06B55144C95A3A5310B4AD6D1CE" xlink:to="loc_us-gaap_LiabilitiesCurrent_8FFAEE7AA679E0F74B52310B4AD68384" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_825B37150017AC6BFCF3310B4AD66C37" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_825B37150017AC6BFCF3310B4AD66C37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_9CCAD4553274B20FA090310B4AD6836E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_9CCAD4553274B20FA090310B4AD6836E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_2604931135A4AB450515310B4AD68483" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_2604931135A4AB450515310B4AD68483" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_F235693ABF0D814D8089310B4AD6ADDA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_Liabilities_F235693ABF0D814D8089310B4AD6ADDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_766977282B2AF4C2FE8B310B4AD61264" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_CommitmentsAndContingencies_766977282B2AF4C2FE8B310B4AD61264" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_29B839F97A1A12593A64310B4AD6D459" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:to="loc_us-gaap_CommonStockValue_29B839F97A1A12593A64310B4AD6D459" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="loc_us-gaap_TreasuryStockValue_31632EBD37CF4531731A310B4AD62C11" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:to="loc_us-gaap_TreasuryStockValue_31632EBD37CF4531731A310B4AD62C11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_4D1A1D2DA0DF6F602A0C310B4AD62835" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_4D1A1D2DA0DF6F602A0C310B4AD62835" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_6E19894B0B12430A2294310B4AD6E3EE" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_6E19894B0B12430A2294310B4AD6E3EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_2E0F27A196218F5E1224310B4AD6F9F2" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_2E0F27A196218F5E1224310B4AD6F9F2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_5A6DFCD86F1600FF28B0310B4AD65D22" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_EF8A2F3003F6E9A50D08310B4AD6E2DF" xlink:to="loc_us-gaap_StockholdersEquity_5A6DFCD86F1600FF28B0310B4AD65D22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_1B0F4AC941648D3CF039310B4AD6471D" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_33B9545283322F63224F310B4AD6AD8E" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_1B0F4AC941648D3CF039310B4AD6471D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2A0ED8578976DFAEB133ECCE2C75FEAC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:to="loc_us-gaap_StatementTable_2A0ED8578976DFAEB133ECCE2C75FEAC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_90B8E45CBFE1857DCA9DECCE2C75481F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2A0ED8578976DFAEB133ECCE2C75FEAC" xlink:to="loc_us-gaap_StatementClassOfStockAxis_90B8E45CBFE1857DCA9DECCE2C75481F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_90B8E45CBFE1857DCA9DECCE2C75481F" xlink:to="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_90B8E45CBFE1857DCA9DECCE2C75481F" xlink:to="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_7AD8B67F024C32E7C045ECCE2C750C47" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7" xlink:to="loc_us-gaap_CommonClassAMember_7AD8B67F024C32E7C045ECCE2C750C47" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_25F5B2907EE9CA30AEAEECCE2C76B2F8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7" xlink:to="loc_us-gaap_CommonClassBMember_25F5B2907EE9CA30AEAEECCE2C76B2F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_5E16440ED7ADCA18FE88ECCE2C76FC25" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7" xlink:to="loc_us-gaap_CommonClassCMember_5E16440ED7ADCA18FE88ECCE2C76FC25" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_CommonClassEMember" xlink:label="loc_bah_CommonClassEMember_613D58F94344AABF43F0ECCE2C761C0D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6A60D9FFFF49A531EB46ECCE2C75F3E7" xlink:to="loc_bah_CommonClassEMember_613D58F94344AABF43F0ECCE2C761C0D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_076F886C01CA75D53295ECCE2C76F0AE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_076F886C01CA75D53295ECCE2C76F0AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_537BEAE83BA296957594ECCE2C766FC3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_537BEAE83BA296957594ECCE2C766FC3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_9AA6BAB0E5BD0A28501DECCE2C77533E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:to="loc_us-gaap_CommonStockSharesIssued_9AA6BAB0E5BD0A28501DECCE2C77533E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_A765271E13D5030F8B66ECCE2C77A22C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_A765271E13D5030F8B66ECCE2C77A22C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="loc_us-gaap_TreasuryStockShares_00FE25EB2400FDCEC6B4ECCE2C77909C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_99A4BBD1D867750A99CCECCE2C763E43" xlink:to="loc_us-gaap_TreasuryStockShares_00FE25EB2400FDCEC6B4ECCE2C77909C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/ConsolidatedStatementsOfStockholdersEquityStatement" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_05AA326499AE28C6611EF75F8FD7A14E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_StatementTable_05AA326499AE28C6611EF75F8FD7A14E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_0405126B938397FE3DEAF75F8FD7DBDE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_05AA326499AE28C6611EF75F8FD7A14E" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_0405126B938397FE3DEAF75F8FD7DBDE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0405126B938397FE3DEAF75F8FD7DBDE" xlink:to="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0405126B938397FE3DEAF75F8FD7DBDE" xlink:to="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_DE5D36459317A09ABB9DF75F8FD7D989" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:to="loc_us-gaap_CommonStockMember_DE5D36459317A09ABB9DF75F8FD7D989" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="loc_us-gaap_TreasuryStockMember_F9D3938E436919F6644DF75F8FD8C85A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:to="loc_us-gaap_TreasuryStockMember_F9D3938E436919F6644DF75F8FD8C85A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_FD77F6ABAA9ACDF94378F75F8FD862AA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_FD77F6ABAA9ACDF94378F75F8FD862AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_48CD39BB907CD89B759AF75F8FD8B39B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:to="loc_us-gaap_RetainedEarningsMember_48CD39BB907CD89B759AF75F8FD8B39B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_AC11EC7BDBF6859938E5F75F8FD850CF" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_E8A5323AEDE3FE9E0581F75F8FD70EBD" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_AC11EC7BDBF6859938E5F75F8FD850CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_356C7B8A1589CAEE2DF2F75F8FD870ED" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_05AA326499AE28C6611EF75F8FD7A14E" xlink:to="loc_us-gaap_StatementClassOfStockAxis_356C7B8A1589CAEE2DF2F75F8FD870ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_356C7B8A1589CAEE2DF2F75F8FD870ED" xlink:to="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_356C7B8A1589CAEE2DF2F75F8FD870ED" xlink:to="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_8D727AD9FC40697AA059F75F8FD866D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693" xlink:to="loc_us-gaap_CommonClassAMember_8D727AD9FC40697AA059F75F8FD866D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_DB86013C5A01722ACBBBF75F8FD8248F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693" xlink:to="loc_us-gaap_CommonClassBMember_DB86013C5A01722ACBBBF75F8FD8248F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_708809B7A828FB2819D4F75F8FD89916" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693" xlink:to="loc_us-gaap_CommonClassCMember_708809B7A828FB2819D4F75F8FD89916" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_CommonClassEMember" xlink:label="loc_bah_CommonClassEMember_B7AB3E3F8C45FC08152BF75F8FD83EB6" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ED132BC9E987096ACAFBF75F8FD80693" xlink:to="loc_bah_CommonClassEMember_B7AB3E3F8C45FC08152BF75F8FD83EB6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaap_SharesOutstanding_883082288D5EEC796D04F75F8FD86A19" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_SharesOutstanding_883082288D5EEC796D04F75F8FD86A19" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_2A967CF6ADAC94C7E7C4F75F8FD85FA2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_StockholdersEquity_2A967CF6ADAC94C7E7C4F75F8FD85FA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_6E97A79F9028883CD873F75F8FD848D5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_6E97A79F9028883CD873F75F8FD848D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_0B11D88E8560AF71AEA4F75F8FDEEFDA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_0B11D88E8560AF71AEA4F75F8FDEEFDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_7A1A289B37BC026FCFF8F75F8FDE92A8" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_7A1A289B37BC026FCFF8F75F8FDE92A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_85B7E245CE79EAC92CBBF75F8FDE5B3D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_85B7E245CE79EAC92CBBF75F8FDE5B3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation_21D1FA569BC22442A4CEF75F8FDFD5CB" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation_21D1FA569BC22442A4CEF75F8FDFD5CB" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_StockIssuedDuringPeriodSharesShareExchange" xlink:label="loc_bah_StockIssuedDuringPeriodSharesShareExchange_2EC6239833D65EFD5057F75F8FDF9619" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_bah_StockIssuedDuringPeriodSharesShareExchange_2EC6239833D65EFD5057F75F8FDF9619" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_StockIssuedDuringPeriodValueShareExchange" xlink:label="loc_bah_StockIssuedDuringPeriodValueShareExchange_F3A6DD2486A5A9788155F75F8FDF9089" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_bah_StockIssuedDuringPeriodValueShareExchange_F3A6DD2486A5A9788155F75F8FDF9089" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_FC6EB10789634F4F1063F75F8FDF41AD" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_FC6EB10789634F4F1063F75F8FDF41AD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_9B80BBC3F030DA7F3A1EF75F8FDFC78C" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_9B80BBC3F030DA7F3A1EF75F8FDFC78C" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AdjustmentsToAdditionalPaidInCapitalRecognitionOfLiabilityRelatedToFutureStockOptionExercises" xlink:label="loc_bah_AdjustmentsToAdditionalPaidInCapitalRecognitionOfLiabilityRelatedToFutureStockOptionExercises_7E7FDF7754C3F21FA63EF75F8FDF0808" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_bah_AdjustmentsToAdditionalPaidInCapitalRecognitionOfLiabilityRelatedToFutureStockOptionExercises_7E7FDF7754C3F21FA63EF75F8FDF0808" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_46AA1941D25C94933FA5F75F8FDF442E" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_NetIncomeLoss_46AA1941D25C94933FA5F75F8FDF442E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_393B00DF42A62D3435D5F75F8FDF24C0" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_393B00DF42A62D3435D5F75F8FDF24C0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_8ECC54715B2FA4BFDCBAF75F8FDF2CC4" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_8ECC54715B2FA4BFDCBAF75F8FDF2CC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsCash" xlink:label="loc_us-gaap_DividendsCash_BF25502D57A3A00BC884F75F8FDFBFCE" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_DividendsCash_BF25502D57A3A00BC884F75F8FDFBFCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_C3305075FA8770D50A1AF75F8FDF2FC1" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_1E12238C5134E66D8D64F75F8FD8F956" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_C3305075FA8770D50A1AF75F8FDF2FC1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/Debt" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DebtDebtDetailOfInterestExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_4A80305109D60B2F618BECCE2E119C49" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:to="loc_us-gaap_DebtInstrumentTable_4A80305109D60B2F618BECCE2E119C49" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_BDD43DF01CDD74D9D339ECCE2E12F572" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A80305109D60B2F618BECCE2E119C49" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_BDD43DF01CDD74D9D339ECCE2E12F572" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_16863B2C944DE2136ECEECCE2E124D97_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_BDD43DF01CDD74D9D339ECCE2E12F572" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_16863B2C944DE2136ECEECCE2E124D97_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_16863B2C944DE2136ECEECCE2E124D97" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_BDD43DF01CDD74D9D339ECCE2E12F572" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_16863B2C944DE2136ECEECCE2E124D97" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_817B792B5C929C681582ECCE2E12AAAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_16863B2C944DE2136ECEECCE2E124D97" xlink:to="loc_us-gaap_SecuredDebtMember_817B792B5C929C681582ECCE2E12AAAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_E7F3E72EE77BB8FA897DECCE2E12EC8C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_16863B2C944DE2136ECEECCE2E124D97" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_E7F3E72EE77BB8FA897DECCE2E12EC8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_D366E244D0635DD0AE3DECCE2E12C953" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4A80305109D60B2F618BECCE2E119C49" xlink:to="loc_us-gaap_DebtInstrumentAxis_D366E244D0635DD0AE3DECCE2E12C953" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_F50941D926A3871F6DABECCE2E12695D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_D366E244D0635DD0AE3DECCE2E12C953" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_F50941D926A3871F6DABECCE2E12695D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_F50941D926A3871F6DABECCE2E12695D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_D366E244D0635DD0AE3DECCE2E12C953" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_F50941D926A3871F6DABECCE2E12695D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheALoansMember" xlink:label="loc_bah_TrancheALoansMember_625E75666BB6B4DB6A43ECCE2E12220F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F50941D926A3871F6DABECCE2E12695D" xlink:to="loc_bah_TrancheALoansMember_625E75666BB6B4DB6A43ECCE2E12220F" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheBLoansMember" xlink:label="loc_bah_TrancheBLoansMember_A204E04664548E45A197ECCE2E123822" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F50941D926A3871F6DABECCE2E12695D" xlink:to="loc_bah_TrancheBLoansMember_A204E04664548E45A197ECCE2E123822" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="loc_us-gaap_InterestExpenseDebt_C642C257DD0F8A1C0DA4ECCE2E131C0D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:to="loc_us-gaap_InterestExpenseDebt_C642C257DD0F8A1C0DA4ECCE2E131C0D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DeferredPaymentObligationInterestPayment" xlink:label="loc_bah_DeferredPaymentObligationInterestPayment_817EE4AA2E9DC5B55BD4ECCE2E137EF1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:to="loc_bah_DeferredPaymentObligationInterestPayment_817EE4AA2E9DC5B55BD4ECCE2E137EF1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_87B388717EF6F094C974ECCE2E13DDB2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_87B388717EF6F094C974ECCE2E13DDB2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpenseOther" xlink:label="loc_us-gaap_InterestExpenseOther_3A1C34379D2CB187A69EECCE2E13A487" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:to="loc_us-gaap_InterestExpenseOther_3A1C34379D2CB187A69EECCE2E13A487" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_3F6952AA5120B43250EFECCE2E1324BC" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_4E128371D40055D827EDECCE2E131A12" xlink:to="loc_us-gaap_InterestExpense_3F6952AA5120B43250EFECCE2E1324BC" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DebtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_59720D4C148AC4B2420D238A772F73C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_59720D4C148AC4B2420D238A772F73C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_EC5D852773BBB2E8CE55238A772F631B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_59720D4C148AC4B2420D238A772F73C2" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_EC5D852773BBB2E8CE55238A772F631B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_EC5D852773BBB2E8CE55238A772F631B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_59720D4C148AC4B2420D238A772F73C2" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_EC5D852773BBB2E8CE55238A772F631B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherExpenseMember" xlink:label="loc_us-gaap_OtherExpenseMember_3923FBFB5DF07C99D802238A772F7DD4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_EC5D852773BBB2E8CE55238A772F631B" xlink:to="loc_us-gaap_OtherExpenseMember_3923FBFB5DF07C99D802238A772F7DD4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_63DD241DEF52D075AFA8238A772F294A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_EC5D852773BBB2E8CE55238A772F631B" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_63DD241DEF52D075AFA8238A772F294A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_EA41F4D91710E4E9E30E238A772F76B0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_EA41F4D91710E4E9E30E238A772F76B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_EA41F4D91710E4E9E30E238A772F76B0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_EA41F4D91710E4E9E30E238A772F76B0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_2591536E62A0BF16B3F9238A7730BFBD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324" xlink:to="loc_us-gaap_SecuredDebtMember_2591536E62A0BF16B3F9238A7730BFBD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_61A426C7D1BC0399997A238A7730782C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_61A426C7D1BC0399997A238A7730782C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LetterOfCreditMember" xlink:label="loc_us-gaap_LetterOfCreditMember_C71C69F7856A5D55D0AA238A77301EB0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FD4ACADCB9E5BB2A461B238A772F0324" xlink:to="loc_us-gaap_LetterOfCreditMember_C71C69F7856A5D55D0AA238A77301EB0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_2D94036CC58E86D0A8F5238A7730EA6D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:to="loc_us-gaap_DebtInstrumentAxis_2D94036CC58E86D0A8F5238A7730EA6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_2D94036CC58E86D0A8F5238A7730EA6D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_2D94036CC58E86D0A8F5238A7730EA6D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_9148958088E83F504801238A773080F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_9148958088E83F504801238A773080F4" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheBLoansMember" xlink:label="loc_bah_TrancheBLoansMember_DA567803FAF73CEDAB53238A77309856" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3" xlink:to="loc_bah_TrancheBLoansMember_DA567803FAF73CEDAB53238A77309856" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheALoansMember" xlink:label="loc_bah_TrancheALoansMember_69B1778DAD89B8D1D3F0238A773078D4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D228698FE365F5D4ED5A238A773032C3" xlink:to="loc_bah_TrancheALoansMember_69B1778DAD89B8D1D3F0238A773078D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_232BBD2E8AB44B3DAF7C238A7732DFBB" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:to="loc_us-gaap_VariableRateAxis_232BBD2E8AB44B3DAF7C238A7732DFBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_232BBD2E8AB44B3DAF7C238A7732DFBB" xlink:to="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_232BBD2E8AB44B3DAF7C238A7732DFBB" xlink:to="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_OvernightFederalFundsRateMember" xlink:label="loc_bah_OvernightFederalFundsRateMember_A42ED96139AEA74B10B6238A7732BD94" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154" xlink:to="loc_bah_OvernightFederalFundsRateMember_A42ED96139AEA74B10B6238A7732BD94" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_39193A1B1E672AFF9928238A77323A8D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_39193A1B1E672AFF9928238A77323A8D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AlternativeBaseRateABRMember" xlink:label="loc_bah_AlternativeBaseRateABRMember_0BF275E2F19B59798727238A77334311" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_AA8826E9DECF425EA078238A77322154" xlink:to="loc_bah_AlternativeBaseRateABRMember_0BF275E2F19B59798727238A77334311" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_A61EB20D3099D85A7A10238A773374DC" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_CF38093C9167575FD6C1238A772F10F4" xlink:to="loc_us-gaap_RangeAxis_A61EB20D3099D85A7A10238A773374DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_06E0A8D91D61D23F4A6D238A77337D3F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_A61EB20D3099D85A7A10238A773374DC" xlink:to="loc_us-gaap_RangeMember_06E0A8D91D61D23F4A6D238A77337D3F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_06E0A8D91D61D23F4A6D238A77337D3F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_A61EB20D3099D85A7A10238A773374DC" xlink:to="loc_us-gaap_RangeMember_06E0A8D91D61D23F4A6D238A77337D3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_7EAEF4D669630314BA6C238A77330EC8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_06E0A8D91D61D23F4A6D238A77337D3F" xlink:to="loc_us-gaap_MinimumMember_7EAEF4D669630314BA6C238A77330EC8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_2D0AE4A0DEFB831D2046238A7733F9B4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_06E0A8D91D61D23F4A6D238A77337D3F" xlink:to="loc_us-gaap_MaximumMember_2D0AE4A0DEFB831D2046238A7733F9B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromIssuanceOfOtherLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfOtherLongTermDebt_CF5AECF01FD472B39A0A238A773334C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfOtherLongTermDebt_CF5AECF01FD472B39A0A238A773334C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_E8B41BD532BD53D0F663238A7733A876" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_E8B41BD532BD53D0F663238A7733A876" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_Writeoffofdebtissuancecostsandcreditorfeesnotqualifyingfordeferral" xlink:label="loc_bah_Writeoffofdebtissuancecostsandcreditorfeesnotqualifyingfordeferral_3CCB63EAD06666990387238A77338B7C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_bah_Writeoffofdebtissuancecostsandcreditorfeesnotqualifyingfordeferral_3CCB63EAD06666990387238A77338B7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_6A9BF2BF03EC3D4AC590238A7734B25D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_6A9BF2BF03EC3D4AC590238A7734B25D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfDebt_DC9ACAD80C36E973FD86238A7734913B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfDebt_DC9ACAD80C36E973FD86238A7734913B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_E3880EA1219ED0D6B8DD238A77346B6E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_E3880EA1219ED0D6B8DD238A77346B6E" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_LongtermDebtMaximumExpandedLoanFacility" xlink:label="loc_bah_LongtermDebtMaximumExpandedLoanFacility_9E4E4570A7B60921AFA1238A77346EE7" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_bah_LongtermDebtMaximumExpandedLoanFacility_9E4E4570A7B60921AFA1238A77346EE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_69326F3E2AA11306BF8E238A77345804" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_69326F3E2AA11306BF8E238A77345804" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_E520618E9152F1B14CA9238A773470D9" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_LineOfCredit_E520618E9152F1B14CA9238A773470D9" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DebtInstrumentQuarterlyPeriodicPaymentPercentagePrincipal" xlink:label="loc_bah_DebtInstrumentQuarterlyPeriodicPaymentPercentagePrincipal_860762AB307881F95580238A77347855" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_bah_DebtInstrumentQuarterlyPeriodicPaymentPercentagePrincipal_860762AB307881F95580238A77347855" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_378198FBA92D028203A9238A773428DE" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_378198FBA92D028203A9238A773428DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_C272D44979D4879845E9238A7734B8C3" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_C272D44979D4879845E9238A7734B8C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestPaid" xlink:label="loc_us-gaap_InterestPaid_D9EDAB822B3BEDA3E8EE238A77347D9A" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9912F1EFBE38B499ABA5238A77336FF6" xlink:to="loc_us-gaap_InterestPaid_D9EDAB822B3BEDA3E8EE238A77347D9A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DebtFutureDebtPrincipalRepaymentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_8D5C05A04B0ECF48FE5C1974DE6C70CE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_DebtInstrumentTable_8D5C05A04B0ECF48FE5C1974DE6C70CE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_0FA59A78E4DC86A3397E1974DE6C3C01" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8D5C05A04B0ECF48FE5C1974DE6C70CE" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_0FA59A78E4DC86A3397E1974DE6C3C01" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_243F0BECCB57214A885A1974DE6C4D9A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0FA59A78E4DC86A3397E1974DE6C3C01" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_243F0BECCB57214A885A1974DE6C4D9A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_243F0BECCB57214A885A1974DE6C4D9A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0FA59A78E4DC86A3397E1974DE6C3C01" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_243F0BECCB57214A885A1974DE6C4D9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_8F6191A16284A2A37DAB1974DE6CF151" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_243F0BECCB57214A885A1974DE6C4D9A" xlink:to="loc_us-gaap_SecuredDebtMember_8F6191A16284A2A37DAB1974DE6CF151" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_DDBCC4485D831FFBACD11974DE6C9E05" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8D5C05A04B0ECF48FE5C1974DE6C70CE" xlink:to="loc_us-gaap_DebtInstrumentAxis_DDBCC4485D831FFBACD11974DE6C9E05" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_70D2F234A7B20CE30CF81974DE6C113A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_DDBCC4485D831FFBACD11974DE6C9E05" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_70D2F234A7B20CE30CF81974DE6C113A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_70D2F234A7B20CE30CF81974DE6C113A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_DDBCC4485D831FFBACD11974DE6C9E05" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_70D2F234A7B20CE30CF81974DE6C113A" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheALoansMember" xlink:label="loc_bah_TrancheALoansMember_C36F40C821801ED867DB1974DE6CCAC7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_70D2F234A7B20CE30CF81974DE6C113A" xlink:to="loc_bah_TrancheALoansMember_C36F40C821801ED867DB1974DE6CCAC7" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheBLoansMember" xlink:label="loc_bah_TrancheBLoansMember_131E613739C45A8E29471974DE6C7730" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_70D2F234A7B20CE30CF81974DE6C113A" xlink:to="loc_bah_TrancheBLoansMember_131E613739C45A8E29471974DE6C7730" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_20E48F7B30D777A44E301974DE6CDBFA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_20E48F7B30D777A44E301974DE6CDBFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_B8EC5DB1098119F7AC761974DE6CE47D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_B8EC5DB1098119F7AC761974DE6CE47D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_9DCAC52BDE8A581A9BE41974DE6CDD1F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_9DCAC52BDE8A581A9BE41974DE6CDD1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_3EE84AE6D9C47F65E09C1974DE6CD1B0" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_3EE84AE6D9C47F65E09C1974DE6CD1B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_222A5D92F75139CA78011974DE6CCF62" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_222A5D92F75139CA78011974DE6CCF62" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_9AD5242E3AF10DC1D46E1974DE6CC46B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_9AD5242E3AF10DC1D46E1974DE6CC46B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_560934E352FD653320201974DE6C9D52" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3B4116F82B7F2AAEDCD51974DE6C26C1" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_560934E352FD653320201974DE6C9D52" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DebtScheduleOfDebtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_B6188A78C569BBB700B91974DDC247CF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_8C033C5812339FE326A31974DDC26843" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_B6188A78C569BBB700B91974DDC247CF" xlink:to="loc_us-gaap_DebtInstrumentTable_8C033C5812339FE326A31974DDC26843" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_E0ECD0D3E29036694922197937CF383C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8C033C5812339FE326A31974DDC26843" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_E0ECD0D3E29036694922197937CF383C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ECA2E68423B605B5851E19793861E752_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_E0ECD0D3E29036694922197937CF383C" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ECA2E68423B605B5851E19793861E752_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ECA2E68423B605B5851E19793861E752" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_E0ECD0D3E29036694922197937CF383C" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ECA2E68423B605B5851E19793861E752" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherExpenseMember" xlink:label="loc_us-gaap_OtherExpenseMember_4A6824E39CCFDAD8217E197938B72A57" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ECA2E68423B605B5851E19793861E752" xlink:to="loc_us-gaap_OtherExpenseMember_4A6824E39CCFDAD8217E197938B72A57" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_9D091F7851AD5D10546519793982CC74" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ECA2E68423B605B5851E19793861E752" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_9D091F7851AD5D10546519793982CC74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_D5215FF9A1CFF2FB65D21974DDC2582D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8C033C5812339FE326A31974DDC26843" xlink:to="loc_us-gaap_VariableRateAxis_D5215FF9A1CFF2FB65D21974DDC2582D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_C30ED75F9E8A09C9E65F1974DDC232F4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_D5215FF9A1CFF2FB65D21974DDC2582D" xlink:to="loc_us-gaap_VariableRateDomain_C30ED75F9E8A09C9E65F1974DDC232F4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_C30ED75F9E8A09C9E65F1974DDC232F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_D5215FF9A1CFF2FB65D21974DDC2582D" xlink:to="loc_us-gaap_VariableRateDomain_C30ED75F9E8A09C9E65F1974DDC232F4" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AlternativeBaseRateABRMember" xlink:label="loc_bah_AlternativeBaseRateABRMember_449EA61466D8B022D72A1974DDC2383A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_C30ED75F9E8A09C9E65F1974DDC232F4" xlink:to="loc_bah_AlternativeBaseRateABRMember_449EA61466D8B022D72A1974DDC2383A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_3B68EEDC1799BE9EC1051974DDC28360" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_C30ED75F9E8A09C9E65F1974DDC232F4" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_3B68EEDC1799BE9EC1051974DDC28360" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_6C01F5CF9C1977EC28E31974DDC2E31B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8C033C5812339FE326A31974DDC26843" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_6C01F5CF9C1977EC28E31974DDC2E31B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3D1C712763BB23BFC3CF1974DDC2FDCC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6C01F5CF9C1977EC28E31974DDC2E31B" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3D1C712763BB23BFC3CF1974DDC2FDCC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3D1C712763BB23BFC3CF1974DDC2FDCC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6C01F5CF9C1977EC28E31974DDC2E31B" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3D1C712763BB23BFC3CF1974DDC2FDCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_8237135B2C6F85761B581974DDC215E5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3D1C712763BB23BFC3CF1974DDC2FDCC" xlink:to="loc_us-gaap_SecuredDebtMember_8237135B2C6F85761B581974DDC215E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_4B2C05115F44EB735CBD1974DDC25392" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3D1C712763BB23BFC3CF1974DDC2FDCC" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_4B2C05115F44EB735CBD1974DDC25392" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_D5F47BC74910C69A5E7F1974DDC24018" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_8C033C5812339FE326A31974DDC26843" xlink:to="loc_us-gaap_DebtInstrumentAxis_D5F47BC74910C69A5E7F1974DDC24018" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_32F34FF77623A01C35FC1974DDC210D8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_D5F47BC74910C69A5E7F1974DDC24018" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_32F34FF77623A01C35FC1974DDC210D8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_32F34FF77623A01C35FC1974DDC210D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_D5F47BC74910C69A5E7F1974DDC24018" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_32F34FF77623A01C35FC1974DDC210D8" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheALoansMember" xlink:label="loc_bah_TrancheALoansMember_F11F4FF670FAF65380A71974DDC260C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_32F34FF77623A01C35FC1974DDC210D8" xlink:to="loc_bah_TrancheALoansMember_F11F4FF670FAF65380A71974DDC260C2" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_TrancheBLoansMember" xlink:label="loc_bah_TrancheBLoansMember_F7611E772842E351AE9A1974DDC20703" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_32F34FF77623A01C35FC1974DDC210D8" xlink:to="loc_bah_TrancheBLoansMember_F7611E772842E351AE9A1974DDC20703" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_D82830D9771DC1A87320197936722F8F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_B6188A78C569BBB700B91974DDC247CF" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_D82830D9771DC1A87320197936722F8F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtCurrentAndNoncurrentAbstract" xlink:label="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_B6188A78C569BBB700B91974DDC247CF" xlink:to="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_F8F646238A8C27B5DC5B1974DDC2090C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_F8F646238A8C27B5DC5B1974DDC2090C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_70799F7523820A4C73861974DDC25D5B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_70799F7523820A4C73861974DDC25D5B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_2F884FFCACFDD27F65F91974DDC288BE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_2F884FFCACFDD27F65F91974DDC288BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_A78C5C34050A2DADA5DF1974DDC21A7E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_LineOfCredit_A78C5C34050A2DADA5DF1974DDC21A7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_F39744F4577F89B4DFAA1974DDC269DA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_F39744F4577F89B4DFAA1974DDC269DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_34BBEDAB403BA602EAF81974DDC20A88" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_LongTermDebt_34BBEDAB403BA602EAF81974DDC20A88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_0DBE79019CB6FBC459331974DDC293C1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_LongTermDebtCurrent_0DBE79019CB6FBC459331974DDC293C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_7705570F27BF0CDC00091974DDC22D32" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtCurrentAndNoncurrentAbstract_62C173CC4881B0A3D9BC1974DDC2BB8A" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_7705570F27BF0CDC00091974DDC22D32" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_Writeoffofdebtissuancecostsandcreditorfeesnotqualifyingfordeferral" xlink:label="loc_bah_Writeoffofdebtissuancecostsandcreditorfeesnotqualifyingfordeferral_328B43AF33D33E370AFC1979372296D8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_B6188A78C569BBB700B91974DDC247CF" xlink:to="loc_bah_Writeoffofdebtissuancecostsandcreditorfeesnotqualifyingfordeferral_328B43AF33D33E370AFC1979372296D8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DebtTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DeferredPaymentObligation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DeferredPaymentObligationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DeferredPaymentObligationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/DocumentAndEntityInformation" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityInformationLineItems" xlink:label="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntitiesTable" xlink:label="loc_dei_EntitiesTable_92500E3FFDB8DCA62D8EECCE2EBB68AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntitiesTable_92500E3FFDB8DCA62D8EECCE2EBB68AC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_BE2D541883FDEC606BFCECCE2EBCA991" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_92500E3FFDB8DCA62D8EECCE2EBB68AC" xlink:to="loc_us-gaap_StatementClassOfStockAxis_BE2D541883FDEC606BFCECCE2EBCA991" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_BE2D541883FDEC606BFCECCE2EBCA991" xlink:to="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_BE2D541883FDEC606BFCECCE2EBCA991" xlink:to="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_BD8DC3037CFE2667C0A2ECCE2EBCE93D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B" xlink:to="loc_us-gaap_CommonClassAMember_BD8DC3037CFE2667C0A2ECCE2EBCE93D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_DBCEB857AD0B5F39483AECCE2EBCBFF1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B" xlink:to="loc_us-gaap_CommonClassBMember_DBCEB857AD0B5F39483AECCE2EBCBFF1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_04E9338B0E3DD7DAE647ECCE2EBC5548" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B" xlink:to="loc_us-gaap_CommonClassCMember_04E9338B0E3DD7DAE647ECCE2EBC5548" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_CommonClassEMember" xlink:label="loc_bah_CommonClassEMember_5FF4389D142F97505FB5ECCE2EBCB30C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_092001BB1E0134E15B0BECCE2EBC945B" xlink:to="loc_bah_CommonClassEMember_5FF4389D142F97505FB5ECCE2EBCB30C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_2AA40CBB342AA049F4B3ECCE2EBC8D63" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityRegistrantName_2AA40CBB342AA049F4B3ECCE2EBC8D63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_851D32C0FD7BE0D33C2EECCE2EBDEB14" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityCentralIndexKey_851D32C0FD7BE0D33C2EECCE2EBDEB14" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_16D8F4D13B3D5BF68D09ECCE2EBDA23B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_DocumentType_16D8F4D13B3D5BF68D09ECCE2EBDA23B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_5365B8B4BA58298228FDECCE2EBDA934" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_DocumentPeriodEndDate_5365B8B4BA58298228FDECCE2EBDA934" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_D6AEDB274D6A99A7D86DECCE2EBDD7E2" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_AmendmentFlag_D6AEDB274D6A99A7D86DECCE2EBDD7E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_C3BFDA20016E09965A1BECCE2EBD58AC" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_DocumentFiscalYearFocus_C3BFDA20016E09965A1BECCE2EBD58AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_2AB4AD45EF3518B3BE11ECCE2EBD9DEA" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_DocumentFiscalPeriodFocus_2AB4AD45EF3518B3BE11ECCE2EBD9DEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_89CE3A9462AF1A803631ECCE2EC28F89" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_CurrentFiscalYearEndDate_89CE3A9462AF1A803631ECCE2EC28F89" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_238616959D5971E4D3BAECCE2EC285EE" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityFilerCategory_238616959D5971E4D3BAECCE2EC285EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_42DB1230D1D3E34B6450ECCE2EC3D5F1" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_42DB1230D1D3E34B6450ECCE2EC3D5F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="loc_dei_EntityVoluntaryFilers_D7982319F5F40DD8D5C8ECCE2EC34ADE" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityVoluntaryFilers_D7982319F5F40DD8D5C8ECCE2EC34ADE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="loc_dei_EntityCurrentReportingStatus_437B6EDAA38BE269A630ECCE2EC31254" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityCurrentReportingStatus_437B6EDAA38BE269A630ECCE2EC31254" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityPublicFloat" xlink:label="loc_dei_EntityPublicFloat_30DD8D1703E46300677CECCE2EC3DDA7" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityPublicFloat_30DD8D1703E46300677CECCE2EC3DDA7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_345A57B5DFA1630EBE64ECCE2EC3DBC8" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_39F2FE5989CF426F9A7AECCE2EBCDF55" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_345A57B5DFA1630EBE64ECCE2EC3DBC8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EarningsPerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:href="bah-20170331.xsd#bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems" xlink:label="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:type="locator" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassTable" xlink:label="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassTable_FBE9E60733F797F8CE41630BD89DC445" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassTable_FBE9E60733F797F8CE41630BD89DC445" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2E1F7522268F2572275F630BD89D0B53" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassTable_FBE9E60733F797F8CE41630BD89DC445" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2E1F7522268F2572275F630BD89D0B53" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2E1F7522268F2572275F630BD89D0B53" xlink:to="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2E1F7522268F2572275F630BD89D0B53" xlink:to="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_8A3645607F5A4194E323630BD89DC54A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01" xlink:to="loc_us-gaap_CommonClassAMember_8A3645607F5A4194E323630BD89DC54A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassBMember" xlink:label="loc_us-gaap_CommonClassBMember_8CF9C4F0B22A38AC888D630BD89E9280" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01" xlink:to="loc_us-gaap_CommonClassBMember_8CF9C4F0B22A38AC888D630BD89E9280" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_4EFED4ABD97E864460D2630BD89E2BFA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_63F7EC0AA5F5B5097C3A630BD89D2E01" xlink:to="loc_us-gaap_CommonClassCMember_4EFED4ABD97E864460D2630BD89E2BFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_E18511941C0AD7BCC6AC630BD89E2D55" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassTable_FBE9E60733F797F8CE41630BD89DC445" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_E18511941C0AD7BCC6AC630BD89E2D55" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BFF35AE7AE6A7D7310F3630BD89E1238_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_E18511941C0AD7BCC6AC630BD89E2D55" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BFF35AE7AE6A7D7310F3630BD89E1238_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BFF35AE7AE6A7D7310F3630BD89E1238" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_E18511941C0AD7BCC6AC630BD89E2D55" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BFF35AE7AE6A7D7310F3630BD89E1238" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_CA3002B157E5E8F06F20630BD89EAB00" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BFF35AE7AE6A7D7310F3630BD89E1238" xlink:to="loc_us-gaap_RestrictedStockMember_CA3002B157E5E8F06F20630BD89EAB00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_B8E88FFEDD8D54FA32BD630BD89EFF5A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BFF35AE7AE6A7D7310F3630BD89E1238" xlink:to="loc_us-gaap_EmployeeStockOptionMember_B8E88FFEDD8D54FA32BD630BD89EFF5A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UndistributedEarnings" xlink:label="loc_us-gaap_UndistributedEarnings_55A893CFF7476D63D2CB630BD89E25D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_UndistributedEarnings_55A893CFF7476D63D2CB630BD89E25D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_0834A994DAC833A5D022630BD89E4D4D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_0834A994DAC833A5D022630BD89E4D4D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UndistributedEarningsDiluted" xlink:label="loc_us-gaap_UndistributedEarningsDiluted_3A974D3E7592C6558C85630BD89E31F1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_UndistributedEarningsDiluted_3A974D3E7592C6558C85630BD89E31F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_8E2698A4EA9F3F48EC19630BD89FB652" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_8E2698A4EA9F3F48EC19630BD89FB652" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_16A583C2D118346197AC630BD89FDDF2" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_16A583C2D118346197AC630BD89FDDF2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_58B892570832C983ED76630BD89F5DD9" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_EarningsPerShareBasic_58B892570832C983ED76630BD89F5DD9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_026BB74C7F62994C18C8630BD89F4A42" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_EarningsPerShareDiluted_026BB74C7F62994C18C8630BD89F4A42" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights_5F5283F37D2C1BE6AAC2630BD89FE88C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights_5F5283F37D2C1BE6AAC2630BD89FE88C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsOfDividends" xlink:label="loc_us-gaap_PaymentsOfDividends_B3D3048B59B7135EA57A630BD89F2DE1" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_PaymentsOfDividends_B3D3048B59B7135EA57A630BD89F2DE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic" xlink:label="loc_us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic_161FF24FC1D0F89931E3630BD89FCF1A" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic_161FF24FC1D0F89931E3630BD89FCF1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesDiluted" xlink:label="loc_us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesDiluted_E8C5E1CA34A23D4690B6630BD89FCBE0" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesDiluted_E8C5E1CA34A23D4690B6630BD89FCBE0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_8B55BD9CCBA185485F8E630BD89F043A" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_ScheduleOfEarningsPerShareBasicAndDilutedByCommonClassLineItems_1BB2DE3931227629B6C7630BD89E3BB6" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_8B55BD9CCBA185485F8E630BD89F043A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EarningsPerShareTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlans" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_2E9A648AC839FDC941E7310DEB3350BD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D9A4A5E87B752F58431B310DEB3241ED" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_2E9A648AC839FDC941E7310DEB3350BD" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D9A4A5E87B752F58431B310DEB3241ED" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis" xlink:label="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_6DCB05C378AC11DA07DA312058C02D79" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D9A4A5E87B752F58431B310DEB3241ED" xlink:to="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_6DCB05C378AC11DA07DA312058C02D79" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NatureOfErrorDomain" xlink:label="loc_us-gaap_NatureOfErrorDomain_06381354D9EED7D3F51E312058C2BACB_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_6DCB05C378AC11DA07DA312058C02D79" xlink:to="loc_us-gaap_NatureOfErrorDomain_06381354D9EED7D3F51E312058C2BACB_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NatureOfErrorDomain" xlink:label="loc_us-gaap_NatureOfErrorDomain_06381354D9EED7D3F51E312058C2BACB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_6DCB05C378AC11DA07DA312058C02D79" xlink:to="loc_us-gaap_NatureOfErrorDomain_06381354D9EED7D3F51E312058C2BACB" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ImpacttogeneralandadministrativeexpenseMember" xlink:label="loc_bah_ImpacttogeneralandadministrativeexpenseMember_AE1EEFE87D0E691C32A33121C9D1B308" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NatureOfErrorDomain_06381354D9EED7D3F51E312058C2BACB" xlink:to="loc_bah_ImpacttogeneralandadministrativeexpenseMember_AE1EEFE87D0E691C32A33121C9D1B308" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_C2B4CCDBF0D0A1F6C6E8310DEB32CF75" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_D9A4A5E87B752F58431B310DEB3241ED" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_C2B4CCDBF0D0A1F6C6E8310DEB32CF75" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_BD823402AEE84ED27395310DEB330AF9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_C2B4CCDBF0D0A1F6C6E8310DEB32CF75" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_BD823402AEE84ED27395310DEB330AF9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_BD823402AEE84ED27395310DEB330AF9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_C2B4CCDBF0D0A1F6C6E8310DEB32CF75" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_BD823402AEE84ED27395310DEB330AF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:label="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_DFEA1E06DF23A8BB180F310DEB330DCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_BD823402AEE84ED27395310DEB330AF9" xlink:to="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_DFEA1E06DF23A8BB180F310DEB330DCE" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DeferredCompensationArrangementWithIndividualAnnualCashAwardGrantedPerYearOfServiceAmount" xlink:label="loc_bah_DeferredCompensationArrangementWithIndividualAnnualCashAwardGrantedPerYearOfServiceAmount_328E611F036F291F2743310DEB333EDC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_2E9A648AC839FDC941E7310DEB3350BD" xlink:to="loc_bah_DeferredCompensationArrangementWithIndividualAnnualCashAwardGrantedPerYearOfServiceAmount_328E611F036F291F2743310DEB333EDC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PostemploymentBenefitsLiabilityNoncurrent" xlink:label="loc_us-gaap_PostemploymentBenefitsLiabilityNoncurrent_C3CD0762629D33F7C8A13117A8B0AD9A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_2E9A648AC839FDC941E7310DEB3350BD" xlink:to="loc_us-gaap_PostemploymentBenefitsLiabilityNoncurrent_C3CD0762629D33F7C8A13117A8B0AD9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount" xlink:label="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount_6F25F4519184ECE63A58314C3D76EE74" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_2E9A648AC839FDC941E7310DEB3350BD" xlink:to="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount_6F25F4519184ECE63A58314C3D76EE74" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansChangeInBenefitObligationAndChangeInPlanAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_D47ADBCA5EABFD658D5623B9CE936089" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1F7204501DD450FB213B23B9CE936610" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_D47ADBCA5EABFD658D5623B9CE936089" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1F7204501DD450FB213B23B9CE936610" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_C54C71A4E1D3334B924623BBE5538437" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1F7204501DD450FB213B23B9CE936610" xlink:to="loc_us-gaap_TitleOfIndividualAxis_C54C71A4E1D3334B924623BBE5538437" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_EC912C7F11BC16776AC623BBE9A046AB_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_C54C71A4E1D3334B924623BBE5538437" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_EC912C7F11BC16776AC623BBE9A046AB_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_EC912C7F11BC16776AC623BBE9A046AB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_C54C71A4E1D3334B924623BBE5538437" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_EC912C7F11BC16776AC623BBE9A046AB" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_OfficerandVicePresidentMember" xlink:label="loc_bah_OfficerandVicePresidentMember_FB434B8C9A2BEE8EAA3823C26B36BAE9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_EC912C7F11BC16776AC623BBE9A046AB" xlink:to="loc_bah_OfficerandVicePresidentMember_FB434B8C9A2BEE8EAA3823C26B36BAE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OfficerMember" xlink:label="loc_us-gaap_OfficerMember_C3E55194C36A0255219123BBE6EA26BE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_EC912C7F11BC16776AC623BBE9A046AB" xlink:to="loc_us-gaap_OfficerMember_C3E55194C36A0255219123BBE6EA26BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_E49F03CADA87A45A298A23B9CE93AEC5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1F7204501DD450FB213B23B9CE936610" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_E49F03CADA87A45A298A23B9CE93AEC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_E1B5AEE0CA56592E3F8E23B9CE93F60B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_E49F03CADA87A45A298A23B9CE93AEC5" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_E1B5AEE0CA56592E3F8E23B9CE93F60B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_E1B5AEE0CA56592E3F8E23B9CE93F60B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_E49F03CADA87A45A298A23B9CE93AEC5" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_E1B5AEE0CA56592E3F8E23B9CE93F60B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_383294A5E153EFC2418A23B9CE93A074" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_E1B5AEE0CA56592E3F8E23B9CE93F60B" xlink:to="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_383294A5E153EFC2418A23B9CE93A074" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:label="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_025E3DBFF6D9148FD59023B9CE93DF86" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_E1B5AEE0CA56592E3F8E23B9CE93F60B" xlink:to="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_025E3DBFF6D9148FD59023B9CE93DF86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_D47ADBCA5EABFD658D5623B9CE936089" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_7E1FADC48F3088208E1523B9CE9363A1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_7E1FADC48F3088208E1523B9CE9363A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_8D422AEB26C0AEAEA55423B9CE932359" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_8D422AEB26C0AEAEA55423B9CE932359" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_0F3F57818B0D964ADE8323B9CE934CA2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_0F3F57818B0D964ADE8323B9CE934CA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_A7AF7203A228D784382E23B9CE93155F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_A7AF7203A228D784382E23B9CE93155F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitsPaid_0F7F0BC9FF912978E4B623B9CE935F21" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4B1DF5B679DB820E9E8D23B9CE93E097" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitsPaid_0F7F0BC9FF912978E4B623B9CE935F21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_5C024C9446D38AECF0BB23B9CE937E88" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_D47ADBCA5EABFD658D5623B9CE936089" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_5C024C9446D38AECF0BB23B9CE937E88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_11E5529484FE1B08A4F123B9CE9320AF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_5C024C9446D38AECF0BB23B9CE937E88" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_11E5529484FE1B08A4F123B9CE9320AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_807719E99C1CFD3FAEBC23B9CE931FE7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_5C024C9446D38AECF0BB23B9CE937E88" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_807719E99C1CFD3FAEBC23B9CE931FE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_B3AF9CEE38FDFD5479EB23B9CE930964" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_D47ADBCA5EABFD658D5623B9CE936089" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_B3AF9CEE38FDFD5479EB23B9CE930964" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansComponentsOfNetPostretirementMedicalExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8C1084B874DCBE364541ECCE2EDA706A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4A0E30364E079AF0A175ECCE2ED9E192" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8C1084B874DCBE364541ECCE2EDA706A" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4A0E30364E079AF0A175ECCE2ED9E192" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_D93D1F11AFA2CCCF5AF0ECCE2ED9E1CD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4A0E30364E079AF0A175ECCE2ED9E192" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_D93D1F11AFA2CCCF5AF0ECCE2ED9E1CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_B21A1D3620FB7A367E7BECCE2ED9D378_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_D93D1F11AFA2CCCF5AF0ECCE2ED9E1CD" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_B21A1D3620FB7A367E7BECCE2ED9D378_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_B21A1D3620FB7A367E7BECCE2ED9D378" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_D93D1F11AFA2CCCF5AF0ECCE2ED9E1CD" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_B21A1D3620FB7A367E7BECCE2ED9D378" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_A9C51D2B25E41BE119EEECCE2EDA0A49" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_B21A1D3620FB7A367E7BECCE2ED9D378" xlink:to="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_A9C51D2B25E41BE119EEECCE2EDA0A49" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_503C7526BB53D0B3037BECCE2EDAB3BF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8C1084B874DCBE364541ECCE2EDA706A" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_503C7526BB53D0B3037BECCE2EDAB3BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_39520B0C124F113CFA2EECCE2EDA64B5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8C1084B874DCBE364541ECCE2EDA706A" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_39520B0C124F113CFA2EECCE2EDA64B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9302A1968611ADA4A0E1ECCE2EDA20CB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8C1084B874DCBE364541ECCE2EDA706A" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9302A1968611ADA4A0E1ECCE2EDA20CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_6E50C9AB21E10F138615ECCE2EDACC07" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8C1084B874DCBE364541ECCE2EDA706A" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_6E50C9AB21E10F138615ECCE2EDACC07" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansFutureBenefitPaymentsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansHealthcareCostTrendRatesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_F7D5D073229A6C806BAFECCE2BC84B00" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_F7D5D073229A6C806BAFECCE2BC84B00" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_44E08A6A796DB9A2B384ECCE2BC8061B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_F7D5D073229A6C806BAFECCE2BC84B00" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_44E08A6A796DB9A2B384ECCE2BC8061B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_171A51CCD8496CEA7809ECCE2BC8B763_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_44E08A6A796DB9A2B384ECCE2BC8061B" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_171A51CCD8496CEA7809ECCE2BC8B763_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_171A51CCD8496CEA7809ECCE2BC8B763" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_44E08A6A796DB9A2B384ECCE2BC8061B" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_171A51CCD8496CEA7809ECCE2BC8B763" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_9AFBC4F81BBCA8DEDD9DECCE2BC8D4A4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_171A51CCD8496CEA7809ECCE2BC8B763" xlink:to="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_9AFBC4F81BBCA8DEDD9DECCE2BC8D4A4" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearPre65" xlink:label="loc_bah_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearPre65_4EE3346BD532853BCAB9ECCE2BC811CE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_bah_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearPre65_4EE3346BD532853BCAB9ECCE2BC811CE" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DefinedBenefitPlanUltimateHealthCareCostTrendRatePre65" xlink:label="loc_bah_DefinedBenefitPlanUltimateHealthCareCostTrendRatePre65_93B4196CCB95EFDBA9E4ECCE2BC88884" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_bah_DefinedBenefitPlanUltimateHealthCareCostTrendRatePre65_93B4196CCB95EFDBA9E4ECCE2BC88884" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DefinedBenefitPlanYearThatRateReachesUltimateTrendRatePre65" xlink:label="loc_bah_DefinedBenefitPlanYearThatRateReachesUltimateTrendRatePre65_BF2FEE28020A0CFB8152ECCE2BC80143" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_bah_DefinedBenefitPlanYearThatRateReachesUltimateTrendRatePre65_BF2FEE28020A0CFB8152ECCE2BC80143" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearPost65" xlink:label="loc_bah_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearPost65_D1AB94CD1DA6736E280AECCE2BC8C9B7" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_bah_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYearPost65_D1AB94CD1DA6736E280AECCE2BC8C9B7" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DefinedBenefitPlanUltimateHealthCareCostTrendRatePost65" xlink:label="loc_bah_DefinedBenefitPlanUltimateHealthCareCostTrendRatePost65_8BCF2D7BEAB3E7C8944EECCE2BC9E9C6" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_bah_DefinedBenefitPlanUltimateHealthCareCostTrendRatePost65_8BCF2D7BEAB3E7C8944EECCE2BC9E9C6" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DefinedBenefitPlanYearThatRateReachesUltimateTrendRatePost65" xlink:label="loc_bah_DefinedBenefitPlanYearThatRateReachesUltimateTrendRatePost65_178FDB9D5EFE7788097CECCE2BC92FC0" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_bah_DefinedBenefitPlanYearThatRateReachesUltimateTrendRatePost65_178FDB9D5EFE7788097CECCE2BC92FC0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_2F6331BAA43D75DF0B14ECCE2BC9472E" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_2F6331BAA43D75DF0B14ECCE2BC9472E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_5458103458D8A8D8EE64ECCE2BC99FCC" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_5458103458D8A8D8EE64ECCE2BC99FCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_11595BFA24D572F7B33BECCE2BC99310" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_11595BFA24D572F7B33BECCE2BC99310" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1" xlink:label="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_2201CB4463D6E4184A5AECCE2BCA3927" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_FBEA853BC7C0F259EC5CECCE2BC84223" xlink:to="loc_us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_2201CB4463D6E4184A5AECCE2BCA3927" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansRetiredOfficersBonusPlanAndRetiredVpBonusPlanDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_A6BD951401CABEB76FCD2C31EDA1D513" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9C49ED20CF8D992DD8B62C31EDA102D4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_A6BD951401CABEB76FCD2C31EDA1D513" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9C49ED20CF8D992DD8B62C31EDA102D4" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_73E22CE6FB0E7F23DE352C31EDA1D8C7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9C49ED20CF8D992DD8B62C31EDA102D4" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_73E22CE6FB0E7F23DE352C31EDA1D8C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_6EA3A68D7D53C29278BC2C31EDA1C153_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_73E22CE6FB0E7F23DE352C31EDA1D8C7" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_6EA3A68D7D53C29278BC2C31EDA1C153_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_6EA3A68D7D53C29278BC2C31EDA1C153" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_73E22CE6FB0E7F23DE352C31EDA1D8C7" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_6EA3A68D7D53C29278BC2C31EDA1C153" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:label="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_3756DC7F8DE6E93E7E702C31EDA11574" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_6EA3A68D7D53C29278BC2C31EDA1C153" xlink:to="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_3756DC7F8DE6E93E7E702C31EDA11574" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_EB40ED830F55B0E8B3612C31EDA16E26" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9C49ED20CF8D992DD8B62C31EDA102D4" xlink:to="loc_us-gaap_TitleOfIndividualAxis_EB40ED830F55B0E8B3612C31EDA16E26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4966921D17FCE9BCB03A2C31EDA19A52_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_EB40ED830F55B0E8B3612C31EDA16E26" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4966921D17FCE9BCB03A2C31EDA19A52_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4966921D17FCE9BCB03A2C31EDA19A52" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_EB40ED830F55B0E8B3612C31EDA16E26" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4966921D17FCE9BCB03A2C31EDA19A52" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OfficerMember" xlink:label="loc_us-gaap_OfficerMember_8BC7B223B3B46CB7CA3B2C31EDA13428" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4966921D17FCE9BCB03A2C31EDA19A52" xlink:to="loc_us-gaap_OfficerMember_8BC7B223B3B46CB7CA3B2C31EDA13428" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VicePresidentMember" xlink:label="loc_us-gaap_VicePresidentMember_A30966D76F5A91536FD92C31EDA1C492" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4966921D17FCE9BCB03A2C31EDA19A52" xlink:to="loc_us-gaap_VicePresidentMember_A30966D76F5A91536FD92C31EDA1C492" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_40DF58AD7FFC33120ADC2C31EDA1EA67" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_A6BD951401CABEB76FCD2C31EDA1D513" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_40DF58AD7FFC33120ADC2C31EDA1EA67" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitsPaid" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitsPaid_28CA9F47066A6E9B4F3A2C31EDA13E70" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_A6BD951401CABEB76FCD2C31EDA1D513" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitsPaid_28CA9F47066A6E9B4F3A2C31EDA13E70" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_82CE4A811376FDAABBBE2C31EDA144CA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_A6BD951401CABEB76FCD2C31EDA1D513" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_82CE4A811376FDAABBBE2C31EDA144CA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/EmployeeBenefitPlansWeightedAverageDiscountRateDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1987B9FDB6FEAC37099D2C31EDAB18CA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_617C9494EDCDED81A0CB2C31EDAB1181" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1987B9FDB6FEAC37099D2C31EDAB18CA" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_617C9494EDCDED81A0CB2C31EDAB1181" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_60D4A308D562984A4DD72C31EDAB7193" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_617C9494EDCDED81A0CB2C31EDAB1181" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_60D4A308D562984A4DD72C31EDAB7193" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_9C2A0810249A97AA736C2C31EDAB59A8_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_60D4A308D562984A4DD72C31EDAB7193" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_9C2A0810249A97AA736C2C31EDAB59A8_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_9C2A0810249A97AA736C2C31EDAB59A8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_60D4A308D562984A4DD72C31EDAB7193" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_9C2A0810249A97AA736C2C31EDAB59A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_FAA819C473E95AA9E99E2C31EDAB3E6D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_9C2A0810249A97AA736C2C31EDAB59A8" xlink:to="loc_us-gaap_OtherPensionPlansPostretirementOrSupplementalPlansDefinedBenefitMember_FAA819C473E95AA9E99E2C31EDAB3E6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember" xlink:label="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_BAAD7DEAF18A3FCE13A22C31EDAB8B28" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_9C2A0810249A97AA736C2C31EDAB59A8" xlink:to="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_BAAD7DEAF18A3FCE13A22C31EDAB8B28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_D7CC2B6C7F6317A968EB2C31EDABD2BA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_617C9494EDCDED81A0CB2C31EDAB1181" xlink:to="loc_us-gaap_TitleOfIndividualAxis_D7CC2B6C7F6317A968EB2C31EDABD2BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_8A3F71649D51EC8FD3E42C31EDAB1644_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_D7CC2B6C7F6317A968EB2C31EDABD2BA" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_8A3F71649D51EC8FD3E42C31EDAB1644_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_8A3F71649D51EC8FD3E42C31EDAB1644" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_D7CC2B6C7F6317A968EB2C31EDABD2BA" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_8A3F71649D51EC8FD3E42C31EDAB1644" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OfficerMember" xlink:label="loc_us-gaap_OfficerMember_BC4706E2463E8A610E232C31EDAB084F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_8A3F71649D51EC8FD3E42C31EDAB1644" xlink:to="loc_us-gaap_OfficerMember_BC4706E2463E8A610E232C31EDAB084F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VicePresidentMember" xlink:label="loc_us-gaap_VicePresidentMember_C77FD08049452DB18C0D2C31EDAB0462" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_8A3F71649D51EC8FD3E42C31EDAB1644" xlink:to="loc_us-gaap_VicePresidentMember_C77FD08049452DB18C0D2C31EDAB0462" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_AD81F9B298ABB382809C2C31EDAEDDC3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1987B9FDB6FEAC37099D2C31EDAB18CA" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_AD81F9B298ABB382809C2C31EDAEDDC3" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/FairValueMeasurements" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/FairValueMeasurementsFairValueMeasurementsLevel3RollforwardDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/FairValueMeasurementsRecurringFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_6E86192BEDF72B2FAE461F598CF49114" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0E13D723300E148C5D181F598CE58029" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_6E86192BEDF72B2FAE461F598CF49114" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0E13D723300E148C5D181F598CE58029" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A8721A22B83368BF09D1F598CE5D148" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0E13D723300E148C5D181F598CE58029" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A8721A22B83368BF09D1F598CE5D148" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_B67E9A5400BC0DFE1C9B1F598CF4A0E2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A8721A22B83368BF09D1F598CE5D148" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_B67E9A5400BC0DFE1C9B1F598CF4A0E2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_B67E9A5400BC0DFE1C9B1F598CF4A0E2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A8721A22B83368BF09D1F598CE5D148" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_B67E9A5400BC0DFE1C9B1F598CF4A0E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_321FAF57AE1418F55BBD1F598CF4014B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_B67E9A5400BC0DFE1C9B1F598CF4A0E2" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_321FAF57AE1418F55BBD1F598CF4014B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E1617D8EA2FDF0B32B911F598CF4FD21" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0E13D723300E148C5D181F598CE58029" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E1617D8EA2FDF0B32B911F598CF4FD21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E1617D8EA2FDF0B32B911F598CF4FD21" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_E1617D8EA2FDF0B32B911F598CF4FD21" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_8CA7BFAFBAD126AD7D0B1F598CF4B0FD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_8CA7BFAFBAD126AD7D0B1F598CF4B0FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_2B09B4D41E1401A78F841F598CF47EC5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_2B09B4D41E1401A78F841F598CF47EC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_1C54408B93DB38020A5D1F598CF48969" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_AA1E4BC88B42A3FCBEA21F598CF4836F" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_1C54408B93DB38020A5D1F598CF48969" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_B89DB6B99D1D4DDFD6371F598CF4EF0D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0E13D723300E148C5D181F598CE58029" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_B89DB6B99D1D4DDFD6371F598CF4EF0D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_287E854A32DA9178B5931F598CF403E2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_B89DB6B99D1D4DDFD6371F598CF4EF0D" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_287E854A32DA9178B5931F598CF403E2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_287E854A32DA9178B5931F598CF403E2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_B89DB6B99D1D4DDFD6371F598CF4EF0D" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_287E854A32DA9178B5931F598CF403E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashMember" xlink:label="loc_us-gaap_CashMember_380CDB94A1D0526246F31F598CF48B2F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_287E854A32DA9178B5931F598CF403E2" xlink:to="loc_us-gaap_CashMember_380CDB94A1D0526246F31F598CF48B2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="loc_us-gaap_MoneyMarketFundsMember_CC07483EA301AEAB0C081F598CF493A6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_287E854A32DA9178B5931F598CF403E2" xlink:to="loc_us-gaap_MoneyMarketFundsMember_CC07483EA301AEAB0C081F598CF493A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_BE504FDDB50EFD30BC631F598CF48C6E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_0E13D723300E148C5D181F598CE58029" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_BE504FDDB50EFD30BC631F598CF48C6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47E09ECD9DD32EB8797E1F598CF418DF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_BE504FDDB50EFD30BC631F598CF48C6E" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47E09ECD9DD32EB8797E1F598CF418DF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47E09ECD9DD32EB8797E1F598CF418DF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_BE504FDDB50EFD30BC631F598CF48C6E" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47E09ECD9DD32EB8797E1F598CF418DF" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ContingentConsiderationMember" xlink:label="loc_bah_ContingentConsiderationMember_93044648BB80919D5D201F9D08CA68BB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47E09ECD9DD32EB8797E1F598CF418DF" xlink:to="loc_bah_ContingentConsiderationMember_93044648BB80919D5D201F9D08CA68BB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherNoncurrentLiabilitiesMember" xlink:label="loc_us-gaap_OtherNoncurrentLiabilitiesMember_707E5A92F9F66DDE6EE81F598CF4FDF2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_47E09ECD9DD32EB8797E1F598CF418DF" xlink:to="loc_us-gaap_OtherNoncurrentLiabilitiesMember_707E5A92F9F66DDE6EE81F598CF4FDF2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_B51018CC1D425D0927BF1F598CF47F16" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_6E86192BEDF72B2FAE461F598CF49114" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_B51018CC1D425D0927BF1F598CF47F16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureRecurring" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureRecurring_0B6C58C927E6A310098E1F598CF45250" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_6E86192BEDF72B2FAE461F598CF49114" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureRecurring_0B6C58C927E6A310098E1F598CF45250" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_86F5ACFFBC5F420DB1ED1F598CF4CA75" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_6E86192BEDF72B2FAE461F598CF49114" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_86F5ACFFBC5F420DB1ED1F598CF4CA75" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_CashAndCashEquivalentsInvestedInMoneyMarketFundsNetAssetValuePerShare" xlink:label="loc_bah_CashAndCashEquivalentsInvestedInMoneyMarketFundsNetAssetValuePerShare_57DCCC04E2F4CAD6E62F1F598CF401E7" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_6E86192BEDF72B2FAE461F598CF49114" xlink:to="loc_bah_CashAndCashEquivalentsInvestedInMoneyMarketFundsNetAssetValuePerShare_57DCCC04E2F4CAD6E62F1F598CF401E7" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/FairValueMeasurementsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/GoodwillAndIntangibleAssets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsExpectedAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_AA92352E17462B64D4FD4B314FF9A813" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_CE0C6A3459C309855A2B4B314FF9EEB9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_AA92352E17462B64D4FD4B314FF9A813" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_CE0C6A3459C309855A2B4B314FF9EEB9" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_C50B5A986653D986A82B4B314FF92368" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_CE0C6A3459C309855A2B4B314FF9EEB9" xlink:to="loc_us-gaap_RangeAxis_C50B5A986653D986A82B4B314FF92368" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_C50B5A986653D986A82B4B314FF92368" xlink:to="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_C50B5A986653D986A82B4B314FF92368" xlink:to="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_0908F6DDAB5551539C444B314FF9FD1A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265" xlink:to="loc_us-gaap_MinimumMember_0908F6DDAB5551539C444B314FF9FD1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_02CB4F05591CE639D4B14B314FF97BE1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265" xlink:to="loc_us-gaap_MaximumMember_02CB4F05591CE639D4B14B314FF97BE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageMember" xlink:label="loc_us-gaap_WeightedAverageMember_EE12133DD0902B47957E4B314FF9913E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_146D04838869D6F908404B314FF9A265" xlink:to="loc_us-gaap_WeightedAverageMember_EE12133DD0902B47957E4B314FF9913E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_50320710C7B5967339714B314FF9954D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_CE0C6A3459C309855A2B4B314FF9EEB9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_50320710C7B5967339714B314FF9954D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_121B6D1EB3811033D9654B314FF98106_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_50320710C7B5967339714B314FF9954D" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_121B6D1EB3811033D9654B314FF98106_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_121B6D1EB3811033D9654B314FF98106" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_50320710C7B5967339714B314FF9954D" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_121B6D1EB3811033D9654B314FF98106" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_B74C98136A3A1B55E6454B314FF9E3C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_121B6D1EB3811033D9654B314FF98106" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_B74C98136A3A1B55E6454B314FF9E3C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_C751CC73E4AD4E29AE154B314FF996C5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_AA92352E17462B64D4FD4B314FF9A813" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_C751CC73E4AD4E29AE154B314FF996C5" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsFiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_42E654DA2A18D0E86B3E196ED04E78D0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_C9671B958BFEE09E2BE9196ED04DA612" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_42E654DA2A18D0E86B3E196ED04E78D0" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_C9671B958BFEE09E2BE9196ED04DA612" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_82CA480A4787D62FA4EB196ED04EFE98" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_C9671B958BFEE09E2BE9196ED04DA612" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_82CA480A4787D62FA4EB196ED04EFE98" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_736B83E62FFE14622E5C196ED04E2BA9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_82CA480A4787D62FA4EB196ED04EFE98" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_736B83E62FFE14622E5C196ED04E2BA9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_736B83E62FFE14622E5C196ED04E2BA9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_82CA480A4787D62FA4EB196ED04EFE98" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_736B83E62FFE14622E5C196ED04E2BA9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_4A01FBE57F8C1930459D196ED04ECD1C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_736B83E62FFE14622E5C196ED04E2BA9" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_4A01FBE57F8C1930459D196ED04ECD1C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_9D9782FB4187F2B0C454196ED04E2102" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_42E654DA2A18D0E86B3E196ED04E78D0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_9D9782FB4187F2B0C454196ED04E2102" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_C6DF8A00025ED38F1C56196ED04EF4AE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_42E654DA2A18D0E86B3E196ED04E78D0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_C6DF8A00025ED38F1C56196ED04EF4AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_058FC985AFFE18C44485196ED04E188A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_42E654DA2A18D0E86B3E196ED04E78D0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_058FC985AFFE18C44485196ED04E188A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_9C2DC2ADF9A530AD6F49196ED04E8B02" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_42E654DA2A18D0E86B3E196ED04E78D0" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_9C2DC2ADF9A530AD6F49196ED04E8B02" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsGoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems" xlink:label="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_6608B109FA22D8CCF6CF314C3F3DC028" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_B5C93876DEDA20D71BBF314C3F3C6F80" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_6608B109FA22D8CCF6CF314C3F3DC028" xlink:to="loc_us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_B5C93876DEDA20D71BBF314C3F3C6F80" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis" xlink:label="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_B53DFAB9A8EE79E2ECBB314C3F3C467A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfQuantifyingPriorYearMisstatementCorrectedInCurrentYearFinancialStatementsTable_B5C93876DEDA20D71BBF314C3F3C6F80" xlink:to="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_B53DFAB9A8EE79E2ECBB314C3F3C467A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NatureOfErrorDomain" xlink:label="loc_us-gaap_NatureOfErrorDomain_21A10BF59F9159E00F7E314C3F3C7D16_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_B53DFAB9A8EE79E2ECBB314C3F3C467A" xlink:to="loc_us-gaap_NatureOfErrorDomain_21A10BF59F9159E00F7E314C3F3C7D16_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NatureOfErrorDomain" xlink:label="loc_us-gaap_NatureOfErrorDomain_21A10BF59F9159E00F7E314C3F3C7D16" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsByNatureOfErrorAxis_B53DFAB9A8EE79E2ECBB314C3F3C467A" xlink:to="loc_us-gaap_NatureOfErrorDomain_21A10BF59F9159E00F7E314C3F3C7D16" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ImpacttogoodwillMember" xlink:label="loc_bah_ImpacttogoodwillMember_BBD4787C9210E5D65C6B314C3F3CD0C7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NatureOfErrorDomain_21A10BF59F9159E00F7E314C3F3C7D16" xlink:to="loc_bah_ImpacttogoodwillMember_BBD4787C9210E5D65C6B314C3F3CD0C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount" xlink:label="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount_D766D93A3880D76EBC9C314C3F3D3F9E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_6608B109FA22D8CCF6CF314C3F3DC028" xlink:to="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsAmount_D766D93A3880D76EBC9C314C3F3D3F9E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_D10E35D2C7B11961B4AB314C3F3D7080" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_QuantifyingMisstatementInCurrentYearFinancialStatementsLineItems_6608B109FA22D8CCF6CF314C3F3DC028" xlink:to="loc_us-gaap_Goodwill_D10E35D2C7B11961B4AB314C3F3D7080" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/GoodwillAndIntangibleAssetsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/GoodwillAndIntangilbeAssetsIndefiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_CFF3CC55DF2318209A5EECCE2C6ADDCD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_DF77EF3027F0BF905AA7ECCE2C6A1927" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_CFF3CC55DF2318209A5EECCE2C6ADDCD" xlink:to="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_DF77EF3027F0BF905AA7ECCE2C6A1927" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_1117D8DC1B7094F79E14ECCE2C6A487F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_DF77EF3027F0BF905AA7ECCE2C6A1927" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_1117D8DC1B7094F79E14ECCE2C6A487F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_008DD041F7EC3F3A9AB3ECCE2C6AAA03_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_1117D8DC1B7094F79E14ECCE2C6A487F" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_008DD041F7EC3F3A9AB3ECCE2C6AAA03_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_008DD041F7EC3F3A9AB3ECCE2C6AAA03" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_1117D8DC1B7094F79E14ECCE2C6A487F" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_008DD041F7EC3F3A9AB3ECCE2C6AAA03" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_004D160D49BEAE8D033CECCE2C6A93D3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_008DD041F7EC3F3A9AB3ECCE2C6AAA03" xlink:to="loc_us-gaap_TradeNamesMember_004D160D49BEAE8D033CECCE2C6A93D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_D2DB3623F4951E1CF903ECCE2C6AEC5F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_CFF3CC55DF2318209A5EECCE2C6ADDCD" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_D2DB3623F4951E1CF903ECCE2C6AEC5F" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/IncomeTaxesComponentsOfIncomeTaxesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/IncomeTaxesComponentsOfNetDeferredIncomeTaxesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/IncomeTaxesIncomeTaxes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/IncomeTaxesReconciliationOfIncomeTaxDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/IncomeTaxesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/IncomeTaxesUncertainTaxPositionsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/OtherLongTermLiabilities" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/OtherLongTermLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_D84305ECEFACBBE3B22331699725BDCA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_87248CC842844450DB1231699725EC6C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D84305ECEFACBBE3B22331699725BDCA" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_87248CC842844450DB1231699725EC6C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_8ADEC7D50FEE42E32E58316997256D3A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_87248CC842844450DB1231699725EC6C" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_8ADEC7D50FEE42E32E58316997256D3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_F4129E8D86E27D4E22B631699725158F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8ADEC7D50FEE42E32E58316997256D3A" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_F4129E8D86E27D4E22B631699725158F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_F4129E8D86E27D4E22B631699725158F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8ADEC7D50FEE42E32E58316997256D3A" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_F4129E8D86E27D4E22B631699725158F" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_EGovHoldingsInc.dbaAquilentMember" xlink:label="loc_bah_EGovHoldingsInc.dbaAquilentMember_86E80EAAA45F7EED36CD316997253D93" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_F4129E8D86E27D4E22B631699725158F" xlink:to="loc_bah_EGovHoldingsInc.dbaAquilentMember_86E80EAAA45F7EED36CD316997253D93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PostemploymentBenefitsLiabilityNoncurrent" xlink:label="loc_us-gaap_PostemploymentBenefitsLiabilityNoncurrent_84B4A3BEC70E1C50D5A2316F59A5E6C3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D84305ECEFACBBE3B22331699725BDCA" xlink:to="loc_us-gaap_PostemploymentBenefitsLiabilityNoncurrent_84B4A3BEC70E1C50D5A2316F59A5E6C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_7E858C499FF1F3E17B5B316997257CBD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D84305ECEFACBBE3B22331699725BDCA" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_7E858C499FF1F3E17B5B316997257CBD" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/OtherLongTermLiabilitiesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/PropertyAndEquipmentNet" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/PropertyAndEquipmentNetDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_BCDBC3E73C71525896DFECCE2C371B35" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FA4E0DD954848B76602AECCE2C37093D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_BCDBC3E73C71525896DFECCE2C371B35" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FA4E0DD954848B76602AECCE2C37093D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_8409591EE99B0196FB2DECCE2C378149" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_FA4E0DD954848B76602AECCE2C37093D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_8409591EE99B0196FB2DECCE2C378149" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_8409591EE99B0196FB2DECCE2C378149" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_8409591EE99B0196FB2DECCE2C378149" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_EB817A08810ADC99E3B5ECCE2C378D96" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_EB817A08810ADC99E3B5ECCE2C378D96" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="loc_us-gaap_ComputerEquipmentMember_85C10C6A896AAA137018ECCE2C3729E2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:to="loc_us-gaap_ComputerEquipmentMember_85C10C6A896AAA137018ECCE2C3729E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_33FFDA66D7DE43BEB478ECCE2C372D8A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_33FFDA66D7DE43BEB478ECCE2C372D8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_2ADAE076EE8CFB9FF64BECCE2C3782FB" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_2ADAE076EE8CFB9FF64BECCE2C3782FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="loc_us-gaap_SoftwareDevelopmentMember_D5DCF79C663F60BA9A47ECCE2C37EBB4" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_86DAA41F1D806E0FAC0FECCE2C37E356" xlink:to="loc_us-gaap_SoftwareDevelopmentMember_D5DCF79C663F60BA9A47ECCE2C37EBB4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_C21B63E8FB7EE70767C6ECCE2C37C44E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_BCDBC3E73C71525896DFECCE2C371B35" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_C21B63E8FB7EE70767C6ECCE2C37C44E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_81C5C717E1FCA1C891B0ECCE2C37D340" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_BCDBC3E73C71525896DFECCE2C371B35" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_81C5C717E1FCA1C891B0ECCE2C37D340" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_79C3320452F388FE3F1BECCE2C3796BA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_BCDBC3E73C71525896DFECCE2C371B35" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_79C3320452F388FE3F1BECCE2C3796BA" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/PropertyAndEquipmentNetTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/RelatedPartyTransactions" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_87D774F089B2F73364841FA499FDCDAD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D222749C3297079441801FA499F3F9EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_87D774F089B2F73364841FA499FDCDAD" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D222749C3297079441801FA499F3F9EE" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9803189BA5A380FFCB831FA499F3792B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D222749C3297079441801FA499F3F9EE" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9803189BA5A380FFCB831FA499F3792B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_724AEDA21C8EF0D64BA51FA499F3C04E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9803189BA5A380FFCB831FA499F3792B" xlink:to="loc_us-gaap_RelatedPartyDomain_724AEDA21C8EF0D64BA51FA499F3C04E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_724AEDA21C8EF0D64BA51FA499F3C04E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_9803189BA5A380FFCB831FA499F3792B" xlink:to="loc_us-gaap_RelatedPartyDomain_724AEDA21C8EF0D64BA51FA499F3C04E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AffiliatedEntityMember" xlink:label="loc_us-gaap_AffiliatedEntityMember_968733F3BCB773C230D11FA4FF82B720" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_724AEDA21C8EF0D64BA51FA499F3C04E" xlink:to="loc_us-gaap_AffiliatedEntityMember_968733F3BCB773C230D11FA4FF82B720" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_599BA83BFE6167E4BE661FA499F35F15" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_D222749C3297079441801FA499F3F9EE" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_599BA83BFE6167E4BE661FA499F35F15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_A60B0E8CC13D3E48D3C51FA499FDEDE4_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_599BA83BFE6167E4BE661FA499F35F15" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_A60B0E8CC13D3E48D3C51FA499FDEDE4_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_A60B0E8CC13D3E48D3C51FA499FDEDE4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_599BA83BFE6167E4BE661FA499F35F15" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_A60B0E8CC13D3E48D3C51FA499FDEDE4" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_PledgeObligationMember" xlink:label="loc_bah_PledgeObligationMember_CB7B90BD00491F93CD921FA62949C708" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_A60B0E8CC13D3E48D3C51FA499FDEDE4" xlink:to="loc_bah_PledgeObligationMember_CB7B90BD00491F93CD921FA62949C708" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DueToAffiliateCurrent" xlink:label="loc_us-gaap_DueToAffiliateCurrent_2D1879939F3FFE9ABABF1FA47927F1FC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_87D774F089B2F73364841FA499FDCDAD" xlink:to="loc_us-gaap_DueToAffiliateCurrent_2D1879939F3FFE9ABABF1FA47927F1FC" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ManagementAgreementAnnualFee" xlink:label="loc_bah_ManagementAgreementAnnualFee_207E8A1BA396D9DB20641F598CE5DC12" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_87D774F089B2F73364841FA499FDCDAD" xlink:to="loc_bah_ManagementAgreementAnnualFee_207E8A1BA396D9DB20641F598CE5DC12" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_RelatedPartyTransactionManagementAgreementAdvisoryFees" xlink:label="loc_bah_RelatedPartyTransactionManagementAgreementAdvisoryFees_A8E8F0B27D05E18BAF591F598CE51169" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_87D774F089B2F73364841FA499FDCDAD" xlink:to="loc_bah_RelatedPartyTransactionManagementAgreementAdvisoryFees_A8E8F0B27D05E18BAF591F598CE51169" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationSpecialDividendsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7AA2277D88438FC2EE6E1DB846A3CF90" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7AA2277D88438FC2EE6E1DB846A3CF90" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_5658A1D13069421EE5D31DB846A3F44C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7AA2277D88438FC2EE6E1DB846A3CF90" xlink:to="loc_us-gaap_AwardTypeAxis_5658A1D13069421EE5D31DB846A3F44C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_DF1B5511C6D35EAD3AB61DB846A334CB_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_5658A1D13069421EE5D31DB846A3F44C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_DF1B5511C6D35EAD3AB61DB846A334CB_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_DF1B5511C6D35EAD3AB61DB846A334CB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_5658A1D13069421EE5D31DB846A3F44C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_DF1B5511C6D35EAD3AB61DB846A334CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_84DDBA9D9B624D38B63B1DB846A3588F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_DF1B5511C6D35EAD3AB61DB846A334CB" xlink:to="loc_us-gaap_EmployeeStockOptionMember_84DDBA9D9B624D38B63B1DB846A3588F" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeAxis" xlink:label="loc_bah_DividendTypeAxis_0F6226181182EBA843AF1DB846A36A22" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7AA2277D88438FC2EE6E1DB846A3CF90" xlink:to="loc_bah_DividendTypeAxis_0F6226181182EBA843AF1DB846A36A22" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_0834D14FD1A152D4D05E1DB846A3621D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_bah_DividendTypeAxis_0F6226181182EBA843AF1DB846A36A22" xlink:to="loc_bah_DividendTypeDomain_0834D14FD1A152D4D05E1DB846A3621D_default" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_0834D14FD1A152D4D05E1DB846A3621D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_bah_DividendTypeAxis_0F6226181182EBA843AF1DB846A36A22" xlink:to="loc_bah_DividendTypeDomain_0834D14FD1A152D4D05E1DB846A3621D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_SpecialCashDividendMember" xlink:label="loc_bah_SpecialCashDividendMember_13D923353EE17CBD9BBA1DB846A3B581" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_0834D14FD1A152D4D05E1DB846A3621D" xlink:to="loc_bah_SpecialCashDividendMember_13D923353EE17CBD9BBA1DB846A3B581" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_OrdinaryCashDividendMember" xlink:label="loc_bah_OrdinaryCashDividendMember_36F5BA9C2A1BE289DF811DB846A3BCCF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_0834D14FD1A152D4D05E1DB846A3621D" xlink:to="loc_bah_OrdinaryCashDividendMember_36F5BA9C2A1BE289DF811DB846A3BCCF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_E1857E4E45CACA2EF8471DB846A382EF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7AA2277D88438FC2EE6E1DB846A3CF90" xlink:to="loc_us-gaap_PlanNameAxis_E1857E4E45CACA2EF8471DB846A382EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_B4330FF73A84F6B45A7D1DB846A328DC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_E1857E4E45CACA2EF8471DB846A382EF" xlink:to="loc_us-gaap_PlanNameDomain_B4330FF73A84F6B45A7D1DB846A328DC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_B4330FF73A84F6B45A7D1DB846A328DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_E1857E4E45CACA2EF8471DB846A382EF" xlink:to="loc_us-gaap_PlanNameDomain_B4330FF73A84F6B45A7D1DB846A328DC" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AmendedAndRestatedEquityIncentivePlanMember" xlink:label="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_6A6A1BF7BC76FC4E645C1DB846A397EF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_B4330FF73A84F6B45A7D1DB846A328DC" xlink:to="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_6A6A1BF7BC76FC4E645C1DB846A397EF" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_RolloverOptionsMember" xlink:label="loc_bah_RolloverOptionsMember_375F02C7B0D29B0F33D91DB846A35799" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_B4330FF73A84F6B45A7D1DB846A328DC" xlink:to="loc_bah_RolloverOptionsMember_375F02C7B0D29B0F33D91DB846A35799" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_575C3D5B3CEBB92D58461DB846A3BEB9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_575C3D5B3CEBB92D58461DB846A3BEB9" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsDividendEquivalentPerShare" xlink:label="loc_bah_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsDividendEquivalentPerShare_2D2FD4D60AE3D9F438B71DB846A3CC8C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_bah_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsDividendEquivalentPerShare_2D2FD4D60AE3D9F438B71DB846A3CC8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsOfCapitalDistribution" xlink:label="loc_us-gaap_PaymentsOfCapitalDistribution_A940BB9A63D77F6BB1B21DB846A33A6F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_us-gaap_PaymentsOfCapitalDistribution_A940BB9A63D77F6BB1B21DB846A33A6F" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostRecognized" xlink:label="loc_bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostRecognized_D0C7D99DA9A01957B7DF1DB846A3EDEF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostRecognized_D0C7D99DA9A01957B7DF1DB846A3EDEF" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDeferredIncrementalCompensationCost" xlink:label="loc_bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDeferredIncrementalCompensationCost_CC8910B2C20C40259ACB1DB846A33C03" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDeferredIncrementalCompensationCost_CC8910B2C20C40259ACB1DB846A33C03" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDeferredIncrementalCompensationCostRecognitionPeriod" xlink:label="loc_bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDeferredIncrementalCompensationCostRecognitionPeriod_ADC61255A33EAE95BD001DB846A344E9" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_bah_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationDeferredIncrementalCompensationCostRecognitionPeriod_ADC61255A33EAE95BD001DB846A344E9" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DeferredCompensationShareBasedArrangementsLiabilityCurrentAndNoncurrentRecordedAndUnrecorded" xlink:label="loc_bah_DeferredCompensationShareBasedArrangementsLiabilityCurrentAndNoncurrentRecordedAndUnrecorded_BB3C20A6A658D8940DEF1DB846A32EBF" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_bah_DeferredCompensationShareBasedArrangementsLiabilityCurrentAndNoncurrentRecordedAndUnrecorded_BB3C20A6A658D8940DEF1DB846A32EBF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent" xlink:label="loc_us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent_9B482383B32676C9CA711DB846A3251C" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent_9B482383B32676C9CA711DB846A3251C" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DeferredCompensationShareBasedArrangementsLiabilityCurrentAndNoncurrentUnrecorded" xlink:label="loc_bah_DeferredCompensationShareBasedArrangementsLiabilityCurrentAndNoncurrentUnrecorded_2B264CA39BAF422ECCCE1DB846A3A510" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_bah_DeferredCompensationShareBasedArrangementsLiabilityCurrentAndNoncurrentUnrecorded_2B264CA39BAF422ECCCE1DB846A3A510" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_24C63332C9E6FEBF7F6F1DB846A3BACB" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_A040CFE5F538886224AE1DB846A33C27" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_24C63332C9E6FEBF7F6F1DB846A3BACB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationStockBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_C86714005E491B7A0B23197C37369194" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_D7D61F1619728893DDFF197C372FAA5D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_C86714005E491B7A0B23197C37369194" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_D7D61F1619728893DDFF197C372FAA5D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_1840041C20A603C4D88A197C372F2361" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_D7D61F1619728893DDFF197C372FAA5D" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_1840041C20A603C4D88A197C372F2361" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_B01AC132F8B2044C5807197C372F2CBC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1840041C20A603C4D88A197C372F2361" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_B01AC132F8B2044C5807197C372F2CBC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_B01AC132F8B2044C5807197C372F2CBC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1840041C20A603C4D88A197C372F2361" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_B01AC132F8B2044C5807197C372F2CBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfSalesMember" xlink:label="loc_us-gaap_CostOfSalesMember_BB61D95C7CC57F810ACD197C372FB147" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_B01AC132F8B2044C5807197C372F2CBC" xlink:to="loc_us-gaap_CostOfSalesMember_BB61D95C7CC57F810ACD197C372FB147" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_DD5BD45CF1D42CC045A9197C3730D2D9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_B01AC132F8B2044C5807197C372F2CBC" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_DD5BD45CF1D42CC045A9197C3730D2D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_76E94E974684D0F34357197C3730FFE7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_D7D61F1619728893DDFF197C372FAA5D" xlink:to="loc_us-gaap_PlanNameAxis_76E94E974684D0F34357197C3730FFE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_89C089DA284F2480AAF4197C373019D2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_76E94E974684D0F34357197C3730FFE7" xlink:to="loc_us-gaap_PlanNameDomain_89C089DA284F2480AAF4197C373019D2_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_89C089DA284F2480AAF4197C373019D2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_76E94E974684D0F34357197C3730FFE7" xlink:to="loc_us-gaap_PlanNameDomain_89C089DA284F2480AAF4197C373019D2" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AmendedAndRestatedEquityIncentivePlanMember" xlink:label="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_11F0894FE3531CD12965197C37308CC1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_89C089DA284F2480AAF4197C373019D2" xlink:to="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_11F0894FE3531CD12965197C37308CC1" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AnnualIncentivePlanMember" xlink:label="loc_bah_AnnualIncentivePlanMember_BC0078CA955C940202A6197C3730A578" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_11F0894FE3531CD12965197C37308CC1" xlink:to="loc_bah_AnnualIncentivePlanMember_BC0078CA955C940202A6197C3730A578" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_04C15857035D362D733F197C373534C2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_D7D61F1619728893DDFF197C372FAA5D" xlink:to="loc_us-gaap_AwardTypeAxis_04C15857035D362D733F197C373534C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AE6A0226B09F1920824B197C3735B197_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_04C15857035D362D733F197C373534C2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AE6A0226B09F1920824B197C3735B197_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AE6A0226B09F1920824B197C3735B197" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_04C15857035D362D733F197C373534C2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AE6A0226B09F1920824B197C3735B197" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_CC522049DBAB537C0D65197C37359B45" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AE6A0226B09F1920824B197C3735B197" xlink:to="loc_us-gaap_EmployeeStockOptionMember_CC522049DBAB537C0D65197C37359B45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_2DB4A60425CF55E846CC197C37357E04" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AE6A0226B09F1920824B197C3735B197" xlink:to="loc_us-gaap_RestrictedStockMember_2DB4A60425CF55E846CC197C37357E04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2233EA461358A70709DF197C37352E45" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_D7D61F1619728893DDFF197C372FAA5D" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2233EA461358A70709DF197C37352E45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_B8171D023AB08483D507197C37369759_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2233EA461358A70709DF197C37352E45" xlink:to="loc_us-gaap_ClassOfStockDomain_B8171D023AB08483D507197C37369759_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_B8171D023AB08483D507197C37369759" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2233EA461358A70709DF197C37352E45" xlink:to="loc_us-gaap_ClassOfStockDomain_B8171D023AB08483D507197C37369759" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_4F0BF728040B0E952788197C37365011" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_B8171D023AB08483D507197C37369759" xlink:to="loc_us-gaap_CommonClassAMember_4F0BF728040B0E952788197C37365011" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_E48C7E8583AC62AF897B197C3736A2C5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_B8171D023AB08483D507197C37369759" xlink:to="loc_us-gaap_CommonClassCMember_E48C7E8583AC62AF897B197C3736A2C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_DF7698D0D8CCF08A5121197C37360AC7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_C86714005E491B7A0B23197C37369194" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_DF7698D0D8CCF08A5121197C37360AC7" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationStockOptionAndRestrictedStockAwardActivityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1D68E5C44227F821AEC7197C3614AC88" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1D68E5C44227F821AEC7197C3614AC88" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_36312E097628E3A8D8D2197C3614BBE8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1D68E5C44227F821AEC7197C3614AC88" xlink:to="loc_us-gaap_StatementClassOfStockAxis_36312E097628E3A8D8D2197C3614BBE8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_B2BF0D54F88AD6A623E4197C36146AF1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_36312E097628E3A8D8D2197C3614BBE8" xlink:to="loc_us-gaap_ClassOfStockDomain_B2BF0D54F88AD6A623E4197C36146AF1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_B2BF0D54F88AD6A623E4197C36146AF1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_36312E097628E3A8D8D2197C3614BBE8" xlink:to="loc_us-gaap_ClassOfStockDomain_B2BF0D54F88AD6A623E4197C36146AF1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_7D2E542DBFCCDD6B120A197C361476C6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_B2BF0D54F88AD6A623E4197C36146AF1" xlink:to="loc_us-gaap_EmployeeStockOptionMember_7D2E542DBFCCDD6B120A197C361476C6" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeAxis" xlink:label="loc_bah_DividendTypeAxis_D799A525F0B5B1076F53197C36148854" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1D68E5C44227F821AEC7197C3614AC88" xlink:to="loc_bah_DividendTypeAxis_D799A525F0B5B1076F53197C36148854" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_FA3E30A03A15D057FEFC197C3614E2AC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_bah_DividendTypeAxis_D799A525F0B5B1076F53197C36148854" xlink:to="loc_bah_DividendTypeDomain_FA3E30A03A15D057FEFC197C3614E2AC_default" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_FA3E30A03A15D057FEFC197C3614E2AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_bah_DividendTypeAxis_D799A525F0B5B1076F53197C36148854" xlink:to="loc_bah_DividendTypeDomain_FA3E30A03A15D057FEFC197C3614E2AC" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_OrdinaryCashDividendMember" xlink:label="loc_bah_OrdinaryCashDividendMember_EC28B483E65626E616FB197C3614B164" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_FA3E30A03A15D057FEFC197C3614E2AC" xlink:to="loc_bah_OrdinaryCashDividendMember_EC28B483E65626E616FB197C3614B164" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_SpecialCashDividendMember" xlink:label="loc_bah_SpecialCashDividendMember_EBE5D76F7E314F1491CB197C36149B27" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_FA3E30A03A15D057FEFC197C3614E2AC" xlink:to="loc_bah_SpecialCashDividendMember_EBE5D76F7E314F1491CB197C36149B27" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_A4D5F6FDF0F88F7B3DD6197C3615D7DD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1D68E5C44227F821AEC7197C3614AC88" xlink:to="loc_us-gaap_PlanNameAxis_A4D5F6FDF0F88F7B3DD6197C3615D7DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_31DA08695E0D4040A344197C36157DE3_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_A4D5F6FDF0F88F7B3DD6197C3615D7DD" xlink:to="loc_us-gaap_PlanNameDomain_31DA08695E0D4040A344197C36157DE3_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_31DA08695E0D4040A344197C36157DE3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_A4D5F6FDF0F88F7B3DD6197C3615D7DD" xlink:to="loc_us-gaap_PlanNameDomain_31DA08695E0D4040A344197C36157DE3" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AmendedAndRestatedEquityIncentivePlanMember" xlink:label="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_6515C67C21D3C30A7F96197C361AD77C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_31DA08695E0D4040A344197C36157DE3" xlink:to="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_6515C67C21D3C30A7F96197C361AD77C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_7EF9332058FFFDD28805197C361A7639" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1D68E5C44227F821AEC7197C3614AC88" xlink:to="loc_us-gaap_AwardTypeAxis_7EF9332058FFFDD28805197C361A7639" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_927B027A17E720139CB0197C361AAED1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_7EF9332058FFFDD28805197C361A7639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_927B027A17E720139CB0197C361AAED1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_927B027A17E720139CB0197C361AAED1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_7EF9332058FFFDD28805197C361A7639" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_927B027A17E720139CB0197C361AAED1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_C593310DEB157B16F9FA197C361AC157" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_927B027A17E720139CB0197C361AAED1" xlink:to="loc_us-gaap_EmployeeStockOptionMember_C593310DEB157B16F9FA197C361AC157" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_6544F9F9A39D185752E7197C361A4BCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_6544F9F9A39D185752E7197C361A4BCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_204E46B8EFA9713AADE6197C361AB276" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_204E46B8EFA9713AADE6197C361AB276" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_34B14A0B537A76DDD3C0197C361B0380" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_34B14A0B537A76DDD3C0197C361B0380" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1AA7F4B012AC1DC0FD38197C361BADDD" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1AA7F4B012AC1DC0FD38197C361BADDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_BFACE9C9B0E992CB01B5197C361B87AF" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_BFACE9C9B0E992CB01B5197C361B87AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_A5392721CC6FA9C0FE95197C361B027D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_A5392721CC6FA9C0FE95197C361B027D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1EB29892AC5415F2F1FB197C361B608A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1EB29892AC5415F2F1FB197C361B608A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_B2124815CC20482C1A97197C361B39FC" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9323C416AEDF91554D78197C361AEC12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_B2124815CC20482C1A97197C361B39FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_FBCDA1C435CB2F13C296197C361B6971" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_FBCDA1C435CB2F13C296197C361B6971" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_912FE8B91C3D3416C884197C36203BF0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_912FE8B91C3D3416C884197C36203BF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_5EFE51AB50EA5899E189197C3621FC04" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_5EFE51AB50EA5899E189197C3621FC04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_BA255E285F1901110BCC197C3621D97B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_BA255E285F1901110BCC197C3621D97B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_859955477C529482067F197C36214152" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_859955477C529482067F197C36214152" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_4DC02B2F992410C5D783197C36210C5E" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_4DC02B2F992410C5D783197C36210C5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_40F687EB14F26FA5509B197C36213258" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_40F687EB14F26FA5509B197C36213258" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_C1BB0D6F1EBB640EAE19197C36213E85" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_C1BB0D6F1EBB640EAE19197C36213E85" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_CFDAB70CBE52E60D46B1197C36219B36" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_CFDAB70CBE52E60D46B1197C36219B36" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_E3E5F8487E999A39F3AB197C3621BC90" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_5A1AA09FC99A8FABB3D2197C361BC8B2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_E3E5F8487E999A39F3AB197C3621BC90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_8FCCBC849B5AA600286F197C36216ED2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_8FCCBC849B5AA600286F197C36216ED2" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendOptionExercisePriceReductionPerShare" xlink:label="loc_bah_DividendOptionExercisePriceReductionPerShare_5FB3F5E679FAF6B4BF07197C36217C86" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_bah_DividendOptionExercisePriceReductionPerShare_5FB3F5E679FAF6B4BF07197C36217C86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_DA649F20B67663933D3B197C36218A53" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_DA649F20B67663933D3B197C36218A53" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_2496AFA512F88F5F21D8197C3621863E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_2496AFA512F88F5F21D8197C3621863E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_CF88CDB0B2C4A1FBC676197C3621F088" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_CF88CDB0B2C4A1FBC676197C3621F088" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_1D7523F547A897B16F35197C3622B86D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_1D7523F547A897B16F35197C3622B86D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_077546763C16A2BDF015197C362227E2" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_077546763C16A2BDF015197C362227E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_ACE8332C52E391E8CA9D197C36222329" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestAbstract_A08512ABA5321E8B6FC7197C36210176" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_ACE8332C52E391E8CA9D197C36222329" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_EC0454113C1E871317CC197C361A0064" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_269BFAA53652CB2EBE4A197C36277F03" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_269BFAA53652CB2EBE4A197C36277F03" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_6E92AB6E57FABA5666EE197C3627ECE5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_6E92AB6E57FABA5666EE197C3627ECE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_01F5A96ABCF7023CF1F8197C36270509" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_01F5A96ABCF7023CF1F8197C36270509" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_95DEE5D497AE3BAC746A197C362876D6" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_95DEE5D497AE3BAC746A197C362876D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_5BCF70272E4135070A30197C362811B1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_5BCF70272E4135070A30197C362811B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_D2F5D801717E16CA2682197C36284A17" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_D2F5D801717E16CA2682197C36284A17" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_F9F3FBB6E198344B4D34197C36283C33" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_F9F3FBB6E198344B4D34197C36283C33" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_0ABE402834ACA9E73006197C36284F0E" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_49D4B6955DB6D63936BA197C3627E621" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_0ABE402834ACA9E73006197C36284F0E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationStockOptionAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4571B8814410F9ED13C0ECCE2BAB0954" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4571B8814410F9ED13C0ECCE2BAB0954" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeAxis" xlink:label="loc_bah_DividendTypeAxis_F08A6C63031ACFC6D484ECCE2BAB5724" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4571B8814410F9ED13C0ECCE2BAB0954" xlink:to="loc_bah_DividendTypeAxis_F08A6C63031ACFC6D484ECCE2BAB5724" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_00DF92786CA59FE9B84EECCE2BAB6EC6_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_bah_DividendTypeAxis_F08A6C63031ACFC6D484ECCE2BAB5724" xlink:to="loc_bah_DividendTypeDomain_00DF92786CA59FE9B84EECCE2BAB6EC6_default" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_00DF92786CA59FE9B84EECCE2BAB6EC6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_bah_DividendTypeAxis_F08A6C63031ACFC6D484ECCE2BAB5724" xlink:to="loc_bah_DividendTypeDomain_00DF92786CA59FE9B84EECCE2BAB6EC6" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_OrdinaryCashDividendMember" xlink:label="loc_bah_OrdinaryCashDividendMember_C41C4545F77319FAD203ECCE2BABC137" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_00DF92786CA59FE9B84EECCE2BAB6EC6" xlink:to="loc_bah_OrdinaryCashDividendMember_C41C4545F77319FAD203ECCE2BABC137" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_E14CC05A2CF44125BA73ECCE2BAB4CB1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4571B8814410F9ED13C0ECCE2BAB0954" xlink:to="loc_us-gaap_AwardTypeAxis_E14CC05A2CF44125BA73ECCE2BAB4CB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4CC90914472B7329B195ECCE2BAB0F4D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_E14CC05A2CF44125BA73ECCE2BAB4CB1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4CC90914472B7329B195ECCE2BAB0F4D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4CC90914472B7329B195ECCE2BAB0F4D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_E14CC05A2CF44125BA73ECCE2BAB4CB1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4CC90914472B7329B195ECCE2BAB0F4D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_8D92CD64FC4B9450B573ECCE2BABDB5A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4CC90914472B7329B195ECCE2BAB0F4D" xlink:to="loc_us-gaap_EmployeeStockOptionMember_8D92CD64FC4B9450B573ECCE2BABDB5A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_3F908CE2BEC962245CE9ECCE2BAC98DD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4571B8814410F9ED13C0ECCE2BAB0954" xlink:to="loc_us-gaap_RangeAxis_3F908CE2BEC962245CE9ECCE2BAC98DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_9737C150F9E459396EC0ECCE2BAC9C1E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_3F908CE2BEC962245CE9ECCE2BAC98DD" xlink:to="loc_us-gaap_RangeMember_9737C150F9E459396EC0ECCE2BAC9C1E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_9737C150F9E459396EC0ECCE2BAC9C1E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_3F908CE2BEC962245CE9ECCE2BAC98DD" xlink:to="loc_us-gaap_RangeMember_9737C150F9E459396EC0ECCE2BAC9C1E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_BDC38DAAFCF367EDE085ECCE2BAC5730" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_9737C150F9E459396EC0ECCE2BAC9C1E" xlink:to="loc_us-gaap_MinimumMember_BDC38DAAFCF367EDE085ECCE2BAC5730" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_3708392A4EAFE78B29DAECCE2BACEBCC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_9737C150F9E459396EC0ECCE2BAC9C1E" xlink:to="loc_us-gaap_MaximumMember_3708392A4EAFE78B29DAECCE2BACEBCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_4491C371D296A6A92E86ECCE2BAC68E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_4491C371D296A6A92E86ECCE2BAC68E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_10E177A4E628540BBCC5ECCE2BAC1759" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_10E177A4E628540BBCC5ECCE2BAC1759" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_ABD475581F21FDA67440ECCE2BACCF56" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_ABD475581F21FDA67440ECCE2BACCF56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_299713F103C1AEAC4BAAECCE2BACCCD1" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_299713F103C1AEAC4BAAECCE2BACCCD1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_090430CFA153FCF9AC30ECCE2BACC506" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_090430CFA153FCF9AC30ECCE2BACC506" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_66852ABE90B4D135F9F9ECCE2BACC7FB" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_F307B61AD9AE75663214ECCE2BACEE8E" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_66852ABE90B4D135F9F9ECCE2BACC7FB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationStockPlansDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeAxis" xlink:label="loc_bah_DividendTypeAxis_46F425BD65C431BD378D1FD3E281517D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:to="loc_bah_DividendTypeAxis_46F425BD65C431BD378D1FD3E281517D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_244064438CEB09A388CE1FD3E281CEC2_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_bah_DividendTypeAxis_46F425BD65C431BD378D1FD3E281517D" xlink:to="loc_bah_DividendTypeDomain_244064438CEB09A388CE1FD3E281CEC2_default" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_244064438CEB09A388CE1FD3E281CEC2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_bah_DividendTypeAxis_46F425BD65C431BD378D1FD3E281517D" xlink:to="loc_bah_DividendTypeDomain_244064438CEB09A388CE1FD3E281CEC2" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_SpecialCashDividendMember" xlink:label="loc_bah_SpecialCashDividendMember_EF3D995C2C0563746FBD1FD3E28112ED" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_244064438CEB09A388CE1FD3E281CEC2" xlink:to="loc_bah_SpecialCashDividendMember_EF3D995C2C0563746FBD1FD3E28112ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_84237FFD67123EAB40041FD3E281F3D1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:to="loc_us-gaap_TitleOfIndividualAxis_84237FFD67123EAB40041FD3E281F3D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_2D0F47CB1CE482C05BEA1FD3E2816D5C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_84237FFD67123EAB40041FD3E281F3D1" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_2D0F47CB1CE482C05BEA1FD3E2816D5C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_2D0F47CB1CE482C05BEA1FD3E2816D5C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_84237FFD67123EAB40041FD3E281F3D1" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_2D0F47CB1CE482C05BEA1FD3E2816D5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DirectorMember" xlink:label="loc_us-gaap_DirectorMember_CD7BB93D66379DAC63E41FD3E2811E2A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_2D0F47CB1CE482C05BEA1FD3E2816D5C" xlink:to="loc_us-gaap_DirectorMember_CD7BB93D66379DAC63E41FD3E2811E2A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_656053A8742D4C2C31E01FD3E2818EC5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:to="loc_us-gaap_PlanNameAxis_656053A8742D4C2C31E01FD3E2818EC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_76CA7C3D027AE50E7D401FD3E28151AF_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_656053A8742D4C2C31E01FD3E2818EC5" xlink:to="loc_us-gaap_PlanNameDomain_76CA7C3D027AE50E7D401FD3E28151AF_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_76CA7C3D027AE50E7D401FD3E28151AF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_656053A8742D4C2C31E01FD3E2818EC5" xlink:to="loc_us-gaap_PlanNameDomain_76CA7C3D027AE50E7D401FD3E28151AF" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_RolloverOptionsMember" xlink:label="loc_bah_RolloverOptionsMember_AE67BFA6D669FADE89EC1FD3E2816BB7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_76CA7C3D027AE50E7D401FD3E28151AF" xlink:to="loc_bah_RolloverOptionsMember_AE67BFA6D669FADE89EC1FD3E2816BB7" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AmendedAndRestatedEquityIncentivePlanMember" xlink:label="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_1235B9700C5CDB51B96C1FD3E281A908" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_76CA7C3D027AE50E7D401FD3E28151AF" xlink:to="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_1235B9700C5CDB51B96C1FD3E281A908" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AnnualIncentivePlanMember" xlink:label="loc_bah_AnnualIncentivePlanMember_F93E74407B8B2C728B6C1FD3E2818FCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_1235B9700C5CDB51B96C1FD3E281A908" xlink:to="loc_bah_AnnualIncentivePlanMember_F93E74407B8B2C728B6C1FD3E2818FCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_3B4EEC49E8ADDD9826501FD3E2813305" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:to="loc_us-gaap_AwardTypeAxis_3B4EEC49E8ADDD9826501FD3E2813305" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_3B4EEC49E8ADDD9826501FD3E2813305" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_3B4EEC49E8ADDD9826501FD3E2813305" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_8CA71EF2BFABFAD973751FD3E2812CE7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC" xlink:to="loc_us-gaap_EmployeeStockOptionMember_8CA71EF2BFABFAD973751FD3E2812CE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_29D41F1B456AA2CCFCCA1FD3E2817ED6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC" xlink:to="loc_us-gaap_RestrictedStockMember_29D41F1B456AA2CCFCCA1FD3E2817ED6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_2D90FCC662534F5DDF2F1FD3E2813E16" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_598CC9486EDF5838640E1FD3E28118BC" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_2D90FCC662534F5DDF2F1FD3E2813E16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_BF22C6122C2CD310D3E91FD3E281E29B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_37F4C5E7BFB4C19AEA781FD3E281F29B" xlink:to="loc_us-gaap_StatementClassOfStockAxis_BF22C6122C2CD310D3E91FD3E281E29B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_174BDC786AD58928ED291FD3E2937C3A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_BF22C6122C2CD310D3E91FD3E281E29B" xlink:to="loc_us-gaap_ClassOfStockDomain_174BDC786AD58928ED291FD3E2937C3A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_174BDC786AD58928ED291FD3E2937C3A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_BF22C6122C2CD310D3E91FD3E281E29B" xlink:to="loc_us-gaap_ClassOfStockDomain_174BDC786AD58928ED291FD3E2937C3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_9C3BE661FE5E455424C01FD3E293ACBB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_174BDC786AD58928ED291FD3E2937C3A" xlink:to="loc_us-gaap_CommonClassAMember_9C3BE661FE5E455424C01FD3E293ACBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassCMember" xlink:label="loc_us-gaap_CommonClassCMember_D0FD95C0D950112ED25E1FD3E2932DA9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_174BDC786AD58928ED291FD3E2937C3A" xlink:to="loc_us-gaap_CommonClassCMember_D0FD95C0D950112ED25E1FD3E2932DA9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent" xlink:label="loc_us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent_CF977529B579EB512BA71FD3E2937C60" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent_CF977529B579EB512BA71FD3E2937C60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_61F6559EC9650A83FCE61FD3E293BD56" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_61F6559EC9650A83FCE61FD3E293BD56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_CC5CF6924FE5A363BAC91FD3E2939893" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_CC5CF6924FE5A363BAC91FD3E2939893" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_001650A533CDF9149E921FD3E2938879" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_001650A533CDF9149E921FD3E2938879" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ShareBasedCompensationArrangementbyShareBasedPaymentAwardOptionsGrantsinPeriodGrantDateFairValue" xlink:label="loc_bah_ShareBasedCompensationArrangementbyShareBasedPaymentAwardOptionsGrantsinPeriodGrantDateFairValue_8B546575A65844E9E4141FD3E293A12D" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_bah_ShareBasedCompensationArrangementbyShareBasedPaymentAwardOptionsGrantsinPeriodGrantDateFairValue_8B546575A65844E9E4141FD3E293A12D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1753819EC7BDBDFAFF331FD3E2946095" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1753819EC7BDBDFAFF331FD3E2946095" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_A73C1EF157F3520D942A1FD3E294E779" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_A73C1EF157F3520D942A1FD3E294E779" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_5859209C8E8ADAD9952A1FD3E294CBF1" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_5859209C8E8ADAD9952A1FD3E294CBF1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_02411949BB2F52C3243A1FD3E2940C84" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_02411949BB2F52C3243A1FD3E2940C84" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_ShareBasedCompensationArrangementBySharebasedPaymentAwardAnnualIncentivePaymentEquityPortionIncreasePercentage" xlink:label="loc_bah_ShareBasedCompensationArrangementBySharebasedPaymentAwardAnnualIncentivePaymentEquityPortionIncreasePercentage_3CA790F56B134CC6AF031FD3E294A8C2" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_bah_ShareBasedCompensationArrangementBySharebasedPaymentAwardAnnualIncentivePaymentEquityPortionIncreasePercentage_3CA790F56B134CC6AF031FD3E294A8C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_020B0010BBD2FD6A50BA1FD3E294DEA6" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_020B0010BBD2FD6A50BA1FD3E294DEA6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_F62E051AD0036F3CF1A31FD3E294754E" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_F62E051AD0036F3CF1A31FD3E294754E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_4F8FC72B379463943C1F1FD3E294B615" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_4F8FC72B379463943C1F1FD3E294B615" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice_2A02DF4BAE321EFED6701FD3E294B03B" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_SharePrice_2A02DF4BAE321EFED6701FD3E294B03B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_2B90558175D3E14BB0661FD3E294A40C" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_2B90558175D3E14BB0661FD3E294A40C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_08FC72EFA579724818981FD3E29412A7" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_08FC72EFA579724818981FD3E29412A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_4F6919D167299765702E1FD3E294F2C8" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_4F6919D167299765702E1FD3E294F2C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_12D9007138527AC962E81FD3E2947C4B" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_FE6558EBAE60C3028AED1FD3E2939533" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_12D9007138527AC962E81FD3E2947C4B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockBasedCompensationUnrecognizedCompensationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B704D7502563B3BC98B7197C3704DA35" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B704D7502563B3BC98B7197C3704DA35" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_51B166E2E11F8564516F197C37045AE1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B704D7502563B3BC98B7197C3704DA35" xlink:to="loc_us-gaap_PlanNameAxis_51B166E2E11F8564516F197C37045AE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_5F9B0CC9CB2D13E9128D197C37046D0D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_51B166E2E11F8564516F197C37045AE1" xlink:to="loc_us-gaap_PlanNameDomain_5F9B0CC9CB2D13E9128D197C37046D0D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_5F9B0CC9CB2D13E9128D197C37046D0D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_51B166E2E11F8564516F197C37045AE1" xlink:to="loc_us-gaap_PlanNameDomain_5F9B0CC9CB2D13E9128D197C37046D0D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AmendedAndRestatedEquityIncentivePlanMember" xlink:label="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_F1D713F4830FC0CC19C3197C3704DD38" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_5F9B0CC9CB2D13E9128D197C37046D0D" xlink:to="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_F1D713F4830FC0CC19C3197C3704DD38" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_AnnualIncentivePlanMember" xlink:label="loc_bah_AnnualIncentivePlanMember_836E862F0970D5E2D90C197C37047A7C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_AmendedAndRestatedEquityIncentivePlanMember_F1D713F4830FC0CC19C3197C3704DD38" xlink:to="loc_bah_AnnualIncentivePlanMember_836E862F0970D5E2D90C197C37047A7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_71F0F79CB4F74760D084197C3704E6BD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B704D7502563B3BC98B7197C3704DA35" xlink:to="loc_us-gaap_AwardTypeAxis_71F0F79CB4F74760D084197C3704E6BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_C14043C0A4CBD471BF1E197C37043B29_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_71F0F79CB4F74760D084197C3704E6BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_C14043C0A4CBD471BF1E197C37043B29_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_C14043C0A4CBD471BF1E197C37043B29" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_71F0F79CB4F74760D084197C3704E6BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_C14043C0A4CBD471BF1E197C37043B29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_C2D9359F7F02FB3FC977197C370A58AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_C14043C0A4CBD471BF1E197C37043B29" xlink:to="loc_us-gaap_EmployeeStockOptionMember_C2D9359F7F02FB3FC977197C370A58AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_03C7EB4A0E8239C579C6197C370ACBB2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_C14043C0A4CBD471BF1E197C37043B29" xlink:to="loc_us-gaap_RestrictedStockMember_03C7EB4A0E8239C579C6197C370ACBB2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_9032A08B0DC5C61394FB197C370AFB15" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B704D7502563B3BC98B7197C3704DA35" xlink:to="loc_us-gaap_StatementClassOfStockAxis_9032A08B0DC5C61394FB197C370AFB15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_A55C15738F6555358860197C370A521E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9032A08B0DC5C61394FB197C370AFB15" xlink:to="loc_us-gaap_ClassOfStockDomain_A55C15738F6555358860197C370A521E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_A55C15738F6555358860197C370A521E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_9032A08B0DC5C61394FB197C370AFB15" xlink:to="loc_us-gaap_ClassOfStockDomain_A55C15738F6555358860197C370A521E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_786086C1B6C1E30DA507197C370A7108" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_A55C15738F6555358860197C370A521E" xlink:to="loc_us-gaap_CommonClassAMember_786086C1B6C1E30DA507197C370A7108" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_6340716F03BEBAAF9A95197C370AF358" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_6340716F03BEBAAF9A95197C370AF358" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_0ABD50073B8BCF9A4BAF197C370A3849" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_0ABD50073B8BCF9A4BAF197C370A3849" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnrecognizedCompensationCostNext12Months" xlink:label="loc_bah_UnrecognizedCompensationCostNext12Months_26A7FAC7C47A2B0B0AB0197C370ADBCC" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_bah_UnrecognizedCompensationCostNext12Months_26A7FAC7C47A2B0B0AB0197C370ADBCC" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnrecognizedCompensationCostYearTwo" xlink:label="loc_bah_UnrecognizedCompensationCostYearTwo_8E2FFBF1FEEC8BC72115197C370AE127" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_bah_UnrecognizedCompensationCostYearTwo_8E2FFBF1FEEC8BC72115197C370AE127" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnrecognizedCompensationCostYearThree" xlink:label="loc_bah_UnrecognizedCompensationCostYearThree_66CE6E6A994A34BA1B79197C370B1E70" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_bah_UnrecognizedCompensationCostYearThree_66CE6E6A994A34BA1B79197C370B1E70" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnrecognizedCompensationCostYearFour" xlink:label="loc_bah_UnrecognizedCompensationCostYearFour_A9D1EF9CA48E91C8D6C0197C370B8546" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_bah_UnrecognizedCompensationCostYearFour_A9D1EF9CA48E91C8D6C0197C370B8546" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_UnrecognizedCompensationCostYearFive" xlink:label="loc_bah_UnrecognizedCompensationCostYearFive_F07E4A12468B3DB7F81D197C370B0971" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_CA315E414822868D18CB197C370A744B" xlink:to="loc_bah_UnrecognizedCompensationCostYearFive_F07E4A12468B3DB7F81D197C370B0971" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockholdersEquity" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockholdersEquityCommonStockSharesActivityDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockholdersEquityDividendsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_014461CEFB9F98E4B4F2197C3744224E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B35B8032FA3C781BD028197C3744395A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_014461CEFB9F98E4B4F2197C3744224E" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B35B8032FA3C781BD028197C3744395A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeAxis" xlink:label="loc_bah_DividendTypeAxis_4E74AEBE669CA06346BB197C3744851A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B35B8032FA3C781BD028197C3744395A" xlink:to="loc_bah_DividendTypeAxis_4E74AEBE669CA06346BB197C3744851A" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_bah_DividendTypeAxis_4E74AEBE669CA06346BB197C3744851A" xlink:to="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B_default" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendTypeDomain" xlink:label="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_bah_DividendTypeAxis_4E74AEBE669CA06346BB197C3744851A" xlink:to="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_OrdinaryCashDividendMember" xlink:label="loc_bah_OrdinaryCashDividendMember_28938E78AA7F8E180DE2197C3744214A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B" xlink:to="loc_bah_OrdinaryCashDividendMember_28938E78AA7F8E180DE2197C3744214A" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_SpecialCashDividendMember" xlink:label="loc_bah_SpecialCashDividendMember_F545D178CF505837C16C197C37444D0D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B" xlink:to="loc_bah_SpecialCashDividendMember_F545D178CF505837C16C197C37444D0D" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_DividendequivalentMember" xlink:label="loc_bah_DividendequivalentMember_60A537F4B679F0C02331197C3744E6E8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_bah_DividendTypeDomain_A4FDE754B26408FB8D0D197C3744B39B" xlink:to="loc_bah_DividendequivalentMember_60A537F4B679F0C02331197C3744E6E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Dividends" xlink:label="loc_us-gaap_Dividends_A1AC78EEAF50814A11E4197C3744F097" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_014461CEFB9F98E4B4F2197C3744224E" xlink:to="loc_us-gaap_Dividends_A1AC78EEAF50814A11E4197C3744F097" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockDividendsPerShareCashPaid" xlink:label="loc_us-gaap_CommonStockDividendsPerShareCashPaid_7B9716C32CBF96F31E58197C37440EC1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_014461CEFB9F98E4B4F2197C3744224E" xlink:to="loc_us-gaap_CommonStockDividendsPerShareCashPaid_7B9716C32CBF96F31E58197C37440EC1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockholdersEquityEmployeeStockPurchasePlanAndShareRepurchaseProgramDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_75CAA87F109E8CF141DE1FCF8D2CC3E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_75CAA87F109E8CF141DE1FCF8D2CC3E0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_9D6A4741BEF7ABE113781FCF8D2C6393" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_75CAA87F109E8CF141DE1FCF8D2CC3E0" xlink:to="loc_us-gaap_PlanNameAxis_9D6A4741BEF7ABE113781FCF8D2C6393" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_EB6A81EFEFB3351640DB1FCF8D2CE965_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_9D6A4741BEF7ABE113781FCF8D2C6393" xlink:to="loc_us-gaap_PlanNameDomain_EB6A81EFEFB3351640DB1FCF8D2CE965_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_EB6A81EFEFB3351640DB1FCF8D2CE965" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_9D6A4741BEF7ABE113781FCF8D2C6393" xlink:to="loc_us-gaap_PlanNameDomain_EB6A81EFEFB3351640DB1FCF8D2CE965" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_EmployeeStockPurchasePlanMember" xlink:label="loc_bah_EmployeeStockPurchasePlanMember_36F8E94ED65A3CF2A8A01FD3ADD9E537" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_EB6A81EFEFB3351640DB1FCF8D2CE965" xlink:to="loc_bah_EmployeeStockPurchasePlanMember_36F8E94ED65A3CF2A8A01FD3ADD9E537" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_A876F94793DD71869C871FCF8D2CDEE7" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_75CAA87F109E8CF141DE1FCF8D2CC3E0" xlink:to="loc_us-gaap_StatementClassOfStockAxis_A876F94793DD71869C871FCF8D2CDEE7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_669320F8F55019D0195E1FCF8D2C7F2E_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_A876F94793DD71869C871FCF8D2CDEE7" xlink:to="loc_us-gaap_ClassOfStockDomain_669320F8F55019D0195E1FCF8D2C7F2E_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_669320F8F55019D0195E1FCF8D2C7F2E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_A876F94793DD71869C871FCF8D2CDEE7" xlink:to="loc_us-gaap_ClassOfStockDomain_669320F8F55019D0195E1FCF8D2C7F2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonClassAMember" xlink:label="loc_us-gaap_CommonClassAMember_0DCE2B8497D85B2A7E8D1FCF8D2C253F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_669320F8F55019D0195E1FCF8D2C7F2E" xlink:to="loc_us-gaap_CommonClassAMember_0DCE2B8497D85B2A7E8D1FCF8D2C253F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_DC98B4B31262EF137BAE1FCF8D2C0070" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_DC98B4B31262EF137BAE1FCF8D2C0070" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_767EA792FE78E9E62FD31FCF8D2C9C5C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_767EA792FE78E9E62FD31FCF8D2C9C5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_701A6F15459B234AAF7A1FCF8D2C5BF5" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_701A6F15459B234AAF7A1FCF8D2C5BF5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_E9A1CFC07341D1730F921FCF8D2C8E59" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_E9A1CFC07341D1730F921FCF8D2C8E59" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_27690731A42265563E411FCF8D2C8A28" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_27690731A42265563E411FCF8D2C8A28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_A37BF8896F3CFBCE13AE1FCF8D2CC69B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_A37BF8896F3CFBCE13AE1FCF8D2CC69B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_813ABE502CBA25BD391E1FCF8D2CCF28" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_813ABE502CBA25BD391E1FCF8D2CCF28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_0B1DB151D9FE749964D41FCF8D2CEED0" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C61850DB05BF7F0E441D1FCF8D2C58B5" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_0B1DB151D9FE749964D41FCF8D2CEED0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/StockholdersEquityTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SubsequentEvents" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SubsequentEventsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_58A7C06145CDA224956B2DCC03CA4B7C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:to="loc_us-gaap_DebtInstrumentAxis_58A7C06145CDA224956B2DCC03CA4B7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_98295A14264DFB2E178D2DCC03CA009C_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_58A7C06145CDA224956B2DCC03CA4B7C" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_98295A14264DFB2E178D2DCC03CA009C_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_98295A14264DFB2E178D2DCC03CA009C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_58A7C06145CDA224956B2DCC03CA4B7C" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_98295A14264DFB2E178D2DCC03CA009C" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_SeniorNotesDue2025Member" xlink:label="loc_bah_SeniorNotesDue2025Member_877DE98EAE002D32F0712DCC03CAB1DB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_98295A14264DFB2E178D2DCC03CA009C" xlink:to="loc_bah_SeniorNotesDue2025Member_877DE98EAE002D32F0712DCC03CAB1DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_B942DF60F267F39E7C552DCC03CA146F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_B942DF60F267F39E7C552DCC03CA146F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_B915B63DDC52786850832DCC03CA8F77_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_B942DF60F267F39E7C552DCC03CA146F" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_B915B63DDC52786850832DCC03CA8F77_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_B915B63DDC52786850832DCC03CA8F77" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_B942DF60F267F39E7C552DCC03CA146F" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_B915B63DDC52786850832DCC03CA8F77" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_E53F95EC2CC0CE08084E2DCC03CABEC1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_B915B63DDC52786850832DCC03CA8F77" xlink:to="loc_us-gaap_SeniorNotesMember_E53F95EC2CC0CE08084E2DCC03CABEC1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateAxis" xlink:label="loc_us-gaap_VariableRateAxis_172B92434C6D9B3DC9702DCC03D917BC" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:to="loc_us-gaap_VariableRateAxis_172B92434C6D9B3DC9702DCC03D917BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_5902798E38609455C7ED2DCC03D9AC5F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_172B92434C6D9B3DC9702DCC03D917BC" xlink:to="loc_us-gaap_VariableRateDomain_5902798E38609455C7ED2DCC03D9AC5F_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VariableRateDomain" xlink:label="loc_us-gaap_VariableRateDomain_5902798E38609455C7ED2DCC03D9AC5F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_172B92434C6D9B3DC9702DCC03D917BC" xlink:to="loc_us-gaap_VariableRateDomain_5902798E38609455C7ED2DCC03D9AC5F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_44DEB3E89FABA35A3AC12DCC03D9028A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_5902798E38609455C7ED2DCC03D9AC5F" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_44DEB3E89FABA35A3AC12DCC03D9028A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_40F4FD434F42D81BAE082DCC03D95D6D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_40F4FD434F42D81BAE082DCC03D95D6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_339A04365C21452424A72DCC03D95054_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_40F4FD434F42D81BAE082DCC03D95D6D" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_339A04365C21452424A72DCC03D95054_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_339A04365C21452424A72DCC03D95054" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_40F4FD434F42D81BAE082DCC03D95D6D" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_339A04365C21452424A72DCC03D95054" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_412D25A9D6844C583B752DCC03D94DEF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_339A04365C21452424A72DCC03D95054" xlink:to="loc_us-gaap_InterestRateSwapMember_412D25A9D6844C583B752DCC03D94DEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_7A91F70DB28ACCB6BAA52DCC03D9EE7B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_FA15F3D72784BDF01A1F2DCC03CAF07B" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_7A91F70DB28ACCB6BAA52DCC03D9EE7B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_0903C4EAEE7041A1BEFD2DCC03D9228A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_7A91F70DB28ACCB6BAA52DCC03D9EE7B" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_0903C4EAEE7041A1BEFD2DCC03D9228A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_0903C4EAEE7041A1BEFD2DCC03D9228A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_7A91F70DB28ACCB6BAA52DCC03D9EE7B" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_0903C4EAEE7041A1BEFD2DCC03D9228A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_1CA797520E0B9894F7B92DCC03D93CC5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_0903C4EAEE7041A1BEFD2DCC03D9228A" xlink:to="loc_us-gaap_SubsequentEventMember_1CA797520E0B9894F7B92DCC03D93CC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NumberOfInterestRateDerivativesHeld" xlink:label="loc_us-gaap_NumberOfInterestRateDerivativesHeld_FFEAC88BE3D3A9B22E2A2DCC03D9941E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_NumberOfInterestRateDerivativesHeld_FFEAC88BE3D3A9B22E2A2DCC03D9941E" xlink:type="arc" />
    <link:loc xlink:href="bah-20170331.xsd#bah_NumberOfDifferentFinancialInstitutionsEnteredIntoAgreementWith" xlink:label="loc_bah_NumberOfDifferentFinancialInstitutionsEnteredIntoAgreementWith_F6FB97AC566819B627472DCC03D97DCE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_bah_NumberOfDifferentFinancialInstitutionsEnteredIntoAgreementWith_F6FB97AC566819B627472DCC03D97DCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_900A81ECCD135A3BBD3F2DCC03D922A7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_invest_DerivativeNotionalAmount_900A81ECCD135A3BBD3F2DCC03D922A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate" xlink:label="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_DB7A6F6C5D09616DEBB72DCC03D91118" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_DB7A6F6C5D09616DEBB72DCC03D91118" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_E3A42B41680565C7F55C2DCC03D992FA" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_E3A42B41680565C7F55C2DCC03D992FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_E1F53AB9BFC83EAD88F82DCC03D9805C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_E1F53AB9BFC83EAD88F82DCC03D9805C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_2269DD523F9210ECBD732DCC03D9B474" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_2269DD523F9210ECBD732DCC03D9B474" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_D9F4C333AAE285C9BF5E2DCC03D923EA" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_D9F4C333AAE285C9BF5E2DCC03D923EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsPayableDateDeclaredDayMonthAndYear" xlink:label="loc_us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_93571C54D05C974206B32DCC03D97371" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_93571C54D05C974206B32DCC03D97371" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsPayableAmountPerShare" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_13C48B6D85402A6504382DCC03D94DEA" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_13C48B6D85402A6504382DCC03D94DEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_24265E0BD75086C7C8562DCC03D90534" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_24265E0BD75086C7C8562DCC03D90534" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_36EBB488AA3A0BE3F0BE2DCC03D9545A" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_D470AF74EB3BD74430EF2DCC03D99EF0" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_36EBB488AA3A0BE3F0BE2DCC03D9545A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SummaryOfSignificantAccountingPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SummaryOfSignificantAccountingPoliciesIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_619900F119FC0F3A3D46ECCE2DE42FE6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_095D4B61D7B51A9FD40AECCE2DE3AB75" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_619900F119FC0F3A3D46ECCE2DE42FE6" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_095D4B61D7B51A9FD40AECCE2DE3AB75" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_73C0BD0C2E115E52479EECCE2DE3D0F2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_095D4B61D7B51A9FD40AECCE2DE3AB75" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_73C0BD0C2E115E52479EECCE2DE3D0F2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_BDDC2D319B2BD3044A52ECCE2DE3A033_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_73C0BD0C2E115E52479EECCE2DE3D0F2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_BDDC2D319B2BD3044A52ECCE2DE3A033_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_BDDC2D319B2BD3044A52ECCE2DE3A033" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_73C0BD0C2E115E52479EECCE2DE3D0F2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_BDDC2D319B2BD3044A52ECCE2DE3A033" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OrderOrProductionBacklogMember" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_8E868D8406CA7358B218ECCE2DE3310F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_BDDC2D319B2BD3044A52ECCE2DE3A033" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_8E868D8406CA7358B218ECCE2DE3310F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_5EF8A732F9199C54CC13ECCE2DE365CD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_095D4B61D7B51A9FD40AECCE2DE3AB75" xlink:to="loc_us-gaap_RangeAxis_5EF8A732F9199C54CC13ECCE2DE365CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_7229C4CFA98D553AC693ECCE2DE3A425_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_5EF8A732F9199C54CC13ECCE2DE365CD" xlink:to="loc_us-gaap_RangeMember_7229C4CFA98D553AC693ECCE2DE3A425_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_7229C4CFA98D553AC693ECCE2DE3A425" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_5EF8A732F9199C54CC13ECCE2DE365CD" xlink:to="loc_us-gaap_RangeMember_7229C4CFA98D553AC693ECCE2DE3A425" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_4549FC10A36D97C7A170ECCE2DE45D13" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_7229C4CFA98D553AC693ECCE2DE3A425" xlink:to="loc_us-gaap_MinimumMember_4549FC10A36D97C7A170ECCE2DE45D13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_84216872ACBB9A9FB5C7ECCE2DE4EE90" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_7229C4CFA98D553AC693ECCE2DE3A425" xlink:to="loc_us-gaap_MaximumMember_84216872ACBB9A9FB5C7ECCE2DE4EE90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_5F262A41223765F77920ECCE2DE4CB26" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_619900F119FC0F3A3D46ECCE2DE42FE6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_5F262A41223765F77920ECCE2DE4CB26" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SummaryOfSignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_A9AE8220460E8B01DA36ECCE2B81601E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9705841E8F840BEF84D0ECCE2B7FEC56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_A9AE8220460E8B01DA36ECCE2B81601E" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9705841E8F840BEF84D0ECCE2B7FEC56" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE02AB180BE8A64B1292ECCE2B7FC5E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9705841E8F840BEF84D0ECCE2B7FEC56" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE02AB180BE8A64B1292ECCE2B7FC5E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE02AB180BE8A64B1292ECCE2B7FC5E9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_FE02AB180BE8A64B1292ECCE2B7FC5E9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_EA8386D2E3CE167E7B92ECCE2B80CFA3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_EA8386D2E3CE167E7B92ECCE2B80CFA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="loc_us-gaap_ComputerEquipmentMember_345EA8598E20A22DF9A6ECCE2B807A2E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC" xlink:to="loc_us-gaap_ComputerEquipmentMember_345EA8598E20A22DF9A6ECCE2B807A2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_866D819A284A5D1B7215ECCE2B803EAA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_759A52833AB7AC018C0DECCE2B7FA5CC" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_866D819A284A5D1B7215ECCE2B803EAA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_7E2C16658C63249D63EAECCE2B80D3E4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9705841E8F840BEF84D0ECCE2B7FEC56" xlink:to="loc_us-gaap_RangeAxis_7E2C16658C63249D63EAECCE2B80D3E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_F7A2F6F605F56BB10022ECCE2B800873_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_7E2C16658C63249D63EAECCE2B80D3E4" xlink:to="loc_us-gaap_RangeMember_F7A2F6F605F56BB10022ECCE2B800873_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_F7A2F6F605F56BB10022ECCE2B800873" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_7E2C16658C63249D63EAECCE2B80D3E4" xlink:to="loc_us-gaap_RangeMember_F7A2F6F605F56BB10022ECCE2B800873" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_E1E66D8068C1F27A266AECCE2B80C1FA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_F7A2F6F605F56BB10022ECCE2B800873" xlink:to="loc_us-gaap_MinimumMember_E1E66D8068C1F27A266AECCE2B80C1FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_6F077D556FF910EFBC5FECCE2B8103C9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_F7A2F6F605F56BB10022ECCE2B800873" xlink:to="loc_us-gaap_MaximumMember_6F077D556FF910EFBC5FECCE2B8103C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_C6A114249ECA0A1D5049ECCE2B81160F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_A9AE8220460E8B01DA36ECCE2B81601E" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_C6A114249ECA0A1D5049ECCE2B81160F" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SupplementalFinancialInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SupplementalFinancialInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_C8F0B3D03DE3D42EFC2B20DDF24E04CB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_30DDFE6C39FBE3E66D6120DDF24D0EBD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_C8F0B3D03DE3D42EFC2B20DDF24E04CB" xlink:to="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_30DDFE6C39FBE3E66D6120DDF24D0EBD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_E7F764A0B1AB37F0425120DDF24DA8E6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_30DDFE6C39FBE3E66D6120DDF24D0EBD" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_E7F764A0B1AB37F0425120DDF24DA8E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_8EC174CDC7EF60E0497720DDF24E2F2B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_E7F764A0B1AB37F0425120DDF24DA8E6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_8EC174CDC7EF60E0497720DDF24E2F2B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_8EC174CDC7EF60E0497720DDF24E2F2B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_E7F764A0B1AB37F0425120DDF24DA8E6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_8EC174CDC7EF60E0497720DDF24E2F2B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsContinuingOperationsMember" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsContinuingOperationsMember_2A5C8141CB753FEBD3B520DDF24E7E8B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_8EC174CDC7EF60E0497720DDF24E2F2B" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsContinuingOperationsMember_2A5C8141CB753FEBD3B520DDF24E7E8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_5C4907E6CB970AA2DC6520DDF24E8BA2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_C8F0B3D03DE3D42EFC2B20DDF24E04CB" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_5C4907E6CB970AA2DC6520DDF24E8BA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_D997CF2A012E751E196420DDF24EC232" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_5C4907E6CB970AA2DC6520DDF24E8BA2" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_D997CF2A012E751E196420DDF24EC232" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_B072EB29CF8DE35C324620DDF24E1995" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_5C4907E6CB970AA2DC6520DDF24E8BA2" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_B072EB29CF8DE35C324620DDF24E1995" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_D4CF81010202F1A9078F20DDF24E4AF1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_5C4907E6CB970AA2DC6520DDF24E8BA2" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_D4CF81010202F1A9078F20DDF24E4AF1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.boozallen.com/role/SupplementalFinancialInformationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/UnauditedQuarterlyFinancialData" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/UnauditedQuarterlyFinancialDataDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.boozallen.com/role/UnauditedQuarterlyFinancialDataTables" xlink:type="extended" />
</link:linkbase>
