<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2014-07-29</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001604665</issuerCik>
        <issuerName>Westlake Chemical Partners LP</issuerName>
        <issuerTradingSymbol>WLKP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001299504</rptOwnerCik>
            <rptOwnerName>Jenkins Dorothy C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2801 POST OAK BOULEVARD, SUITE 600</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77056</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Units (Limited Partner Interests)</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1436115</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>TTWF LP &amp; TTWF GP LLC</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Subordinated Units (Limited Partner Interests)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Units</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>12686115</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>TTWF LP &amp; TTWF GP LLC</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This Form 3 is being filed in connection with the effectiveness of the Issuer's Registration Statement on Form S-1. Immediately following the closing of the initial public offering of the Issuer, WPT LLC (&quot;WPT&quot;) will own 1,436,115 common units (&quot;Common Units&quot;) and 12,686,115 subordinated units (&quot;Subordinated Units&quot;), representing 55.7% of the outstanding limited partner interests in the Issuer. Westlake Chemical Corporation (&quot;Westlake&quot;) owns 100% of Westlake Olefins Corporation, which owns 100% of Westlake Chemical Investments, Inc., which owns 100% of Westlake Polymers LLC, which owns 100% of WPT. The reporting person may be deemed to indirectly own the Common Units and the Subordinated Units through her ownership interest in TTWF LP, a Delaware limited partnership through which the reporting person indirectly holds 92,010,554 shares of Westlake.</footnote>
        <footnote id="F2">Two trusts for the benefit of members of the Chao family, including the reporting person, are the managers of TTWF GP LLC, a Delaware limited liability company that is the general partner of TTWF LP. The limited partners of TTWF LP are five trusts, principally for the benefit of members of the Chao family, including the reporting person, and two corporations owned, indirectly or directly, by certain of these trusts and by other entities owned by members of the Chao family, including the reporting person. The reporting person shares investment and voting power with respect to the common units beneficially owned by TTWF LP. The reporting person disclaims beneficial ownership of the common units except to the extent of her pecuniary interest therein.</footnote>
        <footnote id="F3">Each subordinated unit will convert into one common unit at the end of the subordination period, which will end if the Issuer has earned and paid an aggregate amount of at least the minimum quarterly distribution multiplied by the total number of outstanding common and subordinated units for each of three consecutive on each outstanding unit for any three consecutive, non-overlapping four-quarter periods ending on or after June 30, 2017, but may end as soon as June 30, 2015 if the Issuer meets additional financial tests described in its partnership agreement. The subordinated units have no expiration date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Dorothy C. Jenkins by J. Iglesias POA</signatureName>
        <signatureDate>2014-07-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
