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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2020-08-25</periodOfReport>

    <dateOfOriginalSubmission>2020-08-26</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001451809</issuerCik>
        <issuerName>SITIME Corp</issuerName>
        <issuerTradingSymbol>SITM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001688236</rptOwnerCik>
            <rptOwnerName>Bonnot Lionel</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SITIME CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>5451 PATRICK HENRY DR.</rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>See Remarks</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-08-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6083</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>65.02</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>124911</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 automatic trading plan adopted by the Reporting Person.</footnote>
        <footnote id="F2">Includes an aggregate of 124,406 shares of common stock issuable pursuant to previously reported restricted stock units that have not vested.</footnote>
        <footnote id="F3">This amended Form 4 is being filed to correct the number of shares originally reported as sold. The original report included the sale of 505 shares which were incorrectly sold by the broker but were not included in the Reporting Person's 10b5-1 automatic trading plan. Those 505 shares have been returned to the Reporting Person.</footnote>
    </footnotes>

    <remarks>EVP, Worldwide Sales and Business Development</remarks>

    <ownerSignature>
        <signatureName>Samsheer Ahamad, Attorney-in-fact</signatureName>
        <signatureDate>2020-11-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
