<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2021-05-07T16:42:57.1316261+00:00 -->
<!-- Version            : 5.0.1.615 -->
<!-- Package ID         : 3e298f1a475d4f0eade0ce6736f3b17f -->
<!-- Copyright (c) 2021 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="smlp_CommonUnitsNotPledgedAsCollateral" name="CommonUnitsNotPledgedAsCollateral" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_ConsiderationForConsensualDebtDischargeAndRestructuring" name="ConsiderationForConsensualDebtDischargeAndRestructuring" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_OrganizationAndBusinessOperationsLineItems" name="OrganizationAndBusinessOperationsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_OrganizationAndBusinessOperationsTable" name="OrganizationAndBusinessOperationsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SummitMidstreamPartnersHoldingsLLCMember" name="SummitMidstreamPartnersHoldingsLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SummitInvestmentsMember" name="SummitInvestmentsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SMPHoldingsMember" name="SMPHoldingsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_EnergyCapitalPartnersMember" name="EnergyCapitalPartnersMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_GatheringServicesandRelatedFeesMember" name="GatheringServicesandRelatedFeesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_NaturalGasNGLAndCondensateSalesMember" name="NaturalGasNGLAndCondensateSalesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_OtherProductsAndServicesMember" name="OtherProductsAndServicesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_UticaShaleSegmentMember" name="UticaShaleSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_WillistonBasinSegmentMember" name="WillistonBasinSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_DJBasinSegmentMember" name="DJBasinSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_PermianBasinSegmentMember" name="PermianBasinSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_PiceanceBasinSegmentMember" name="PiceanceBasinSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_BarnettShaleSegmentMember" name="BarnettShaleSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_MarcellusShaleSegmentMember" name="MarcellusShaleSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_ContractWithCustomerAssetAdditions" name="ContractWithCustomerAssetAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_RevenueFromContractWithCustomerLineItems" name="RevenueFromContractWithCustomerLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_RevenueFromContractWithCustomerTable" name="RevenueFromContractWithCustomerTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_LandandLineFillMember" name="LandandLineFillMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_OhioGatheringCompanyLLCMember" name="OhioGatheringCompanyLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_EquityMethodInvestmentAmortizationofDifferenceBetweenCarryingAmountandUnderlyingEquity" name="EquityMethodInvestmentAmortizationofDifferenceBetweenCarryingAmountandUnderlyingEquity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_SummitMidstreamPartnersLLCMember" name="SummitMidstreamPartnersLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_ContractWithCustomerLiabilityCurrentAdditions" name="ContractWithCustomerLiabilityCurrentAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smlp_ContractWithCustomerLiabilityCurrentRevenueRecognized" name="ContractWithCustomerLiabilityCurrentRevenueRecognized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_ContractWithCustomerLiabilityNoncurrentAdditions" name="ContractWithCustomerLiabilityNoncurrentAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smlp_ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" name="ContractWithCustomerLiabilityNoncurrentReclassificationToCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_SeniorNotesDueMayTwentyTwentyTwoMember" name="SeniorNotesDueMayTwentyTwentyTwoMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_FivePointFivePercentTwoThousandTwentyTwoSeniorNotesMember" name="FivePointFivePercentTwoThousandTwentyTwoSeniorNotesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_FivePointSevenFivePercentTwoThousandTwentyFiveSeniorNotesMember" name="FivePointSevenFivePercentTwoThousandTwentyFiveSeniorNotesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_LineOfCreditFacilityMaturityDateMonthAndYear" name="LineOfCreditFacilityMaturityDateMonthAndYear" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smlp_RatioOfConsolidatedTrailing12monthEBITDAToNetInterestExpense" name="RatioOfConsolidatedTrailing12monthEBITDAToNetInterestExpense" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_RatioOfNetIndebtednessToConsolidatedTrailing12MonthEBITDA" name="RatioOfNetIndebtednessToConsolidatedTrailing12MonthEBITDA" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_RatioOfFirstLienNetIndebtednessToConsolidatedTrailing12MonthEBITDA" name="RatioOfFirstLienNetIndebtednessToConsolidatedTrailing12MonthEBITDA" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_TermLoanCreditFacilityMember" name="TermLoanCreditFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_WorkingCapitalCreditFacilityMember" name="WorkingCapitalCreditFacilityMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_CreditAgreementMember" name="CreditAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SummitHoldingsAndFinanceCorporationMember" name="SummitHoldingsAndFinanceCorporationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_TwoThousandTwentyTwoSeniorNotesMember" name="TwoThousandTwentyTwoSeniorNotesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_TwoThousandTwentyFiveSeniorNotesMember" name="TwoThousandTwentyFiveSeniorNotesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SummitMidstreamHoldingsLLCMember" name="SummitMidstreamHoldingsLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SeniorNotesDue2022Member" name="SeniorNotesDue2022Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_SeniorNotesDue2025Member" name="SeniorNotesDue2025Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_LimitedPartnerCommonUnitsMember" name="LimitedPartnerCommonUnitsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_PartnersCapitalLineItems" name="PartnersCapitalLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_PartnersCapitalTable" name="PartnersCapitalTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_ECPHoldingsWarrantMember" name="ECPHoldingsWarrantMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_NumberOfCommonUnits" name="NumberOfCommonUnits" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_ExchangeOfferExpiredDate" name="ExchangeOfferExpiredDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smlp_NumberOfCommonUnitsExchanged" name="NumberOfCommonUnitsExchanged" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_CommonUnitsNetOfUnitsWithheldForWithholdingTaxes" name="CommonUnitsNetOfUnitsWithheldForWithholdingTaxes" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smlp_DateUptoWhichWarrantsAreExercisable" name="DateUptoWhichWarrantsAreExercisable" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smlp_DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" name="DistributionOfAllAvailableCashMaximumPeriodFollowingEndOfQuarter" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smlp_LongTermIncentivePlanMember" name="LongTermIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_NumberOfDirectors" name="NumberOfDirectors" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smlp_LossContingencyPollutionLiabilityInsurancePolicyCoverage" name="LossContingencyPollutionLiabilityInsurancePolicyCoverage" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_LossContingencyPropertyAndBusinessInterruptionInsurancePolicyCoverage" name="LossContingencyPropertyAndBusinessInterruptionInsurancePolicyCoverage" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_MeadowlarkMidstreamGatheringSystemMember" name="MeadowlarkMidstreamGatheringSystemMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_TwoThousandTwentyRestructuringActivitiesMember" name="TwoThousandTwentyRestructuringActivitiesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_TwoThousandNineteenRestructuringActivitiesMember" name="TwoThousandNineteenRestructuringActivitiesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_OhioGatheringSegmentMember" name="OhioGatheringSegmentMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_CapitalExpenditures" name="CapitalExpenditures" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smlp_DoubleEPipelineLLCMember" name="DoubleEPipelineLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smlp_ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" name="ReconciliationOfNetIncomeToEBITDAAdditionsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
</xsd:schema>
