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      <link:roleType id="GOODWILLDetails" roleURI="http://telos.com/role/GOODWILLDetails">
        <link:definition>9954495 - Disclosure - GOODWILL (Details)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType id="INTANGIBLEASSETSNETFiniteLivedIntangibleAssetsDetails" roleURI="http://telos.com/role/INTANGIBLEASSETSNETFiniteLivedIntangibleAssetsDetails">
        <link:definition>9954496 - Disclosure - INTANGIBLE ASSETS, NET - Finite-Lived Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
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      <link:roleType id="INTANGIBLEASSETSNETFiniteLivedIntangibleAssetsDetails_1" roleURI="http://telos.com/role/INTANGIBLEASSETSNETFiniteLivedIntangibleAssetsDetails_1">
        <link:definition>9954496 - Disclosure - INTANGIBLE ASSETS, NET - Finite-Lived Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType id="INTANGIBLEASSETSNETAmortizationExpenseDetails" roleURI="http://telos.com/role/INTANGIBLEASSETSNETAmortizationExpenseDetails">
        <link:definition>9954497 - Disclosure - INTANGIBLE ASSETS, NET - Amortization Expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType id="OTHERBALANCESHEETCOMPONENTSOtherAssetsDetails" roleURI="http://telos.com/role/OTHERBALANCESHEETCOMPONENTSOtherAssetsDetails">
        <link:definition>9954498 - Disclosure - OTHER BALANCE SHEET COMPONENTS - Other Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OTHERBALANCESHEETCOMPONENTSAccountsPayableandOtherAccruedLiabilitiesDetails" roleURI="http://telos.com/role/OTHERBALANCESHEETCOMPONENTSAccountsPayableandOtherAccruedLiabilitiesDetails">
        <link:definition>9954499 - Disclosure - OTHER BALANCE SHEET COMPONENTS - Accounts Payable and Other Accrued Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType id="OTHERBALANCESHEETCOMPONENTSOtherCurrentLiabilitiesDetails" roleURI="http://telos.com/role/OTHERBALANCESHEETCOMPONENTSOtherCurrentLiabilitiesDetails">
        <link:definition>9954500 - Disclosure - OTHER BALANCE SHEET COMPONENTS - Other Current Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTANDOTHEROBLIGATIONSRevolvingCreditFacilityDetails" roleURI="http://telos.com/role/DEBTANDOTHEROBLIGATIONSRevolvingCreditFacilityDetails">
        <link:definition>9954501 - Disclosure - DEBT AND OTHER OBLIGATIONS - Revolving Credit Facility (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DEBTANDOTHEROBLIGATIONSOtherFinancingObligationsDetails" roleURI="http://telos.com/role/DEBTANDOTHEROBLIGATIONSOtherFinancingObligationsDetails">
        <link:definition>9954502 - Disclosure - DEBT AND OTHER OBLIGATIONS - Other Financing Obligations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONNarrativeDetails" roleURI="http://telos.com/role/STOCKBASEDCOMPENSATIONNarrativeDetails">
        <link:definition>9954503 - Disclosure - STOCK-BASED COMPENSATION - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONStockBasedCompensationExpenseIncurredDetails" roleURI="http://telos.com/role/STOCKBASEDCOMPENSATIONStockBasedCompensationExpenseIncurredDetails">
        <link:definition>9954504 - Disclosure - STOCK-BASED COMPENSATION - Stock-Based Compensation Expense Incurred (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONNonvestedRestrictedStockUnitsActivityDetails" roleURI="http://telos.com/role/STOCKBASEDCOMPENSATIONNonvestedRestrictedStockUnitsActivityDetails">
        <link:definition>9954505 - Disclosure - STOCK-BASED COMPENSATION - Nonvested Restricted Stock Units Activity (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONStockOptionActivityDetails" roleURI="http://telos.com/role/STOCKBASEDCOMPENSATIONStockOptionActivityDetails">
        <link:definition>9954506 - Disclosure - STOCK-BASED COMPENSATION - Stock Option Activity (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SHAREREPURCHASESNarrativeDetails" roleURI="http://telos.com/role/SHAREREPURCHASESNarrativeDetails">
        <link:definition>9954507 - Disclosure - SHARE REPURCHASES - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCUMULATEDOTHERCOMPREHENSIVELOSSDetails" roleURI="http://telos.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSDetails">
        <link:definition>9954508 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LOSSPERSHAREDetails" roleURI="http://telos.com/role/LOSSPERSHAREDetails">
        <link:definition>9954509 - Disclosure - LOSS PER SHARE (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RELATEDPARTYTRANSACTIONSDetails" roleURI="http://telos.com/role/RELATEDPARTYTRANSACTIONSDetails">
        <link:definition>9954510 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTINFORMATIONNarrativeDetails" roleURI="http://telos.com/role/SEGMENTINFORMATIONNarrativeDetails">
        <link:definition>9954511 - Disclosure - SEGMENT INFORMATION - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTINFORMATIONOperationsbyBusinessSegmentDetails" roleURI="http://telos.com/role/SEGMENTINFORMATIONOperationsbyBusinessSegmentDetails">
        <link:definition>9954512 - Disclosure - SEGMENT INFORMATION - Operations by Business Segment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUPPLEMENTALCASHFLOWINFORMATIONCashCashEquivalentsandRestrictedCashDetails" roleURI="http://telos.com/role/SUPPLEMENTALCASHFLOWINFORMATIONCashCashEquivalentsandRestrictedCashDetails">
        <link:definition>9954513 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION - Cash, Cash Equivalents, and Restricted Cash (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUPPLEMENTALCASHFLOWINFORMATIONSupplementalCashFlowInformationDetails" roleURI="http://telos.com/role/SUPPLEMENTALCASHFLOWINFORMATIONSupplementalCashFlowInformationDetails">
        <link:definition>9954514 - Disclosure - SUPPLEMENTAL CASH FLOW INFORMATION - Supplemental Cash Flow Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
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  <xs:element id="tls_DebtInstrumentNumberOfVariableRates" abstract="false" name="DebtInstrumentNumberOfVariableRates" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="tls_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstandingExercisableAndVestedOrExpectedToVest" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstandingExercisableAndVestedOrExpectedToVest" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_LineOfCreditFacilityAccordionFeatureHigherBorrowingCapacityOption" abstract="false" name="LineOfCreditFacilityAccordionFeatureHigherBorrowingCapacityOption" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_EmmettWoodMember" abstract="true" name="EmmettWoodMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_BillContractsReceivableNetOfAllowance" abstract="false" name="BillContractsReceivableNetOfAllowance" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_IntangibleAssetsAmortizationExpense" abstract="false" name="IntangibleAssetsAmortizationExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_ResearchAndDevelopmentNettingMember" abstract="true" name="ResearchAndDevelopmentNettingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="tls_SoftwareLicensesUnderDeliveryOrderMember" abstract="true" name="SoftwareLicensesUnderDeliveryOrderMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_IssuanceOfCommonStockFor401KMatch" abstract="false" name="IssuanceOfCommonStockFor401KMatch" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_FederalGovernmentMember" abstract="true" name="FederalGovernmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_ServiceBasedRSUAwardsMember" abstract="true" name="ServiceBasedRSUAwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_DebtInstrumentCovenantSeniorLeverageRatioMaximum" abstract="false" name="DebtInstrumentCovenantSeniorLeverageRatioMaximum" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="tls_AdjustedTermSecuredOvernightFinancingRateSOFRMember" abstract="true" name="AdjustedTermSecuredOvernightFinancingRateSOFRMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_InProcessSoftwareDevelopmentCostsMember" abstract="true" name="InProcessSoftwareDevelopmentCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="tls_DebtInstrumentIncrementalIncreaseInInterestRateDueToDefault" abstract="false" name="DebtInstrumentIncrementalIncreaseInInterestRateDueToDefault" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="tls_AdjustedDailySimpleSecuredOvernightFinancingRateSOFRMember" abstract="true" name="AdjustedDailySimpleSecuredOvernightFinancingRateSOFRMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_PaymentOfDFTHoldbackAmount" abstract="false" name="PaymentOfDFTHoldbackAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_USDepartmentOfDefenseMember" abstract="true" name="USDepartmentOfDefenseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_CreditAgreementMember" abstract="true" name="CreditAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_TelosIdMember" abstract="true" name="TelosIdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_Two016OmnibusLongTermIncentivePlanMember" abstract="true" name="Two016OmnibusLongTermIncentivePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_IntangibleAssetsTransferredToExtinguishOtherFinancingObligations" abstract="false" name="IntangibleAssetsTransferredToExtinguishOtherFinancingObligations" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_ReceivablesExcludedFromCollateral" abstract="false" name="ReceivablesExcludedFromCollateral" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_StateLocalAndCommercialMember" abstract="true" name="StateLocalAndCommercialMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_AlternativeBaseRateMember" abstract="true" name="AlternativeBaseRateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_SoftwareLicenseDeliveryOrderNumberOfExercisableExtensionOptions" abstract="false" name="SoftwareLicenseDeliveryOrderNumberOfExercisableExtensionOptions" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="tls_DebtInstrumentPriorNoticePeriod" abstract="false" name="DebtInstrumentPriorNoticePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="tls_RevenueTimingOfTransferOfGoodsOrServiceMember" abstract="true" name="RevenueTimingOfTransferOfGoodsOrServiceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_OtherCurrentLiabilitiesOther" abstract="false" name="OtherCurrentLiabilitiesOther" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_WithholdingTaxOnNetShareSettlementUnderOtherCurrentLiabilities" abstract="false" name="WithholdingTaxOnNetShareSettlementUnderOtherCurrentLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_SoftwareLicenseDeliveryOrderPeriodOfExercisableExtensionOptions" abstract="false" name="SoftwareLicenseDeliveryOrderPeriodOfExercisableExtensionOptions" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="tls_CostPlusFixedFeeMember" abstract="true" name="CostPlusFixedFeeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_IncrementalCommonSharesExcludedFromTheDilutiveEffect" abstract="false" name="IncrementalCommonSharesExcludedFromTheDilutiveEffect" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="tls_OtherAccruedExpensesCurrent" abstract="false" name="OtherAccruedExpensesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_PurchaseOfInvestmentInAccountsPayableAndOtherAccruedLiabilities" abstract="false" name="PurchaseOfInvestmentInAccountsPayableAndOtherAccruedLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="tls_SecuritySolutionsSegmentMember" abstract="true" name="SecuritySolutionsSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="tls_SecureNetworksSegmentMember" abstract="true" name="SecureNetworksSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>
