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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-10-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001735707</issuerCik>
        <issuerName>Garrett Motion Inc.</issuerName>
        <issuerTradingSymbol>GTX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001776724</rptOwnerCik>
            <rptOwnerName>FIN Capital Partners LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>336 WEST 37TH STREET, SUITE 200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10018</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Member of 10% owner group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>370000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks>FIN Capital Partners LP (the &quot;Reporting Person&quot;) directly holds 370,000 shares of common stock of Garrett Motion Inc. (the &quot;Company&quot;). Finn Management GP LLC (&quot;FMGP&quot;) is the general partner of the Reporting Person. FIN Capital Management LLC (&quot;FCM&quot;) is the investment manager to the Reporting Person. Mr. Brian A. Finn is the manager of both FMGP and FCM.

The Reporting Person may be deemed to be a member of a group (for purposes of Rule 13d-3 under the Securities Exchange Act of 1934) with the other shareholders of the Company party to the Amended and Restated Coordination Agreement, dated October 20, 2020, filed as Exhibit 99.1 to the Reporting Persons' Schedule 13D filed on October 28, 2020. The Reporting Person disclaims beneficial ownership of any securities reported by any person except to the extent of its pecuniary interest therein.</remarks>

    <ownerSignature>
        <signatureName>FIN Capital Partners LP, By: Finn Management GP LLC, General Partner, By: /s/ Brian A. Finn, Name: Brian A. Finn, Title: Manager</signatureName>
        <signatureDate>2020-10-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
