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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2018-06-07</periodOfReport>

    <dateOfOriginalSubmission>2018-06-08</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001465885</issuerCik>
        <issuerName>Western Asset Mortgage Capital Corp</issuerName>
        <issuerTradingSymbol>WMC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001284574</rptOwnerCik>
            <rptOwnerName>MITCHELL M CHRISTIAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WESTERN ASSET MORTGAGE CAPITAL CORP</rptOwnerStreet1>
            <rptOwnerStreet2>385 EAST COLORADO BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>PASADENA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91101</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2018-06-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6476</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23286</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These restricted stock units will vest on the first anniversary of the date of grant, subject to the reporting person's continued service to Western Asset Mortgage Capital Corporation (the &quot;Company&quot;) through the vesting date, and will be settled in shares of the Company's common stock upon the reporting person's separation from service with the Company.</footnote>
    </footnotes>

    <remarks>This filing restates in its entirety the Form 4 filed with respect to Mr. Mitchell on June 8, 2018 at 12:58 p.m., which reflected a transcription error.</remarks>

    <ownerSignature>
        <signatureName>/s/ Charles A. Ruys de Perez as Attorney-in-Fact</signatureName>
        <signatureDate>2018-06-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
