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

    <schemaVersion>X0407</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001675644</issuerCik>
        <issuerName>FVCBankcorp, Inc.</issuerName>
        <issuerTradingSymbol>FVCB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001752331</rptOwnerCik>
            <rptOwnerName>Deacon Jennifer L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11325 RANDOM HILLS ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>FAIRFAX</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-05-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6800</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9300</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19843</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On January 31, 2023, the Issuer effected a five-for-four stock split in the form of a dividend (the &quot;Stock Split&quot;) of all of its issued and outstanding shares of common stock (&quot;Common Stock&quot;), which resulted in the Reporting Person's ownership of issued and outstanding Common Stock being increased from 2,000 shares of Common Stock to 2,500 shares of Common Stock prior to the disclosed transaction.</footnote>
        <footnote id="F2">On January 31, 2023, the Issuer effected a Stock Split of all of its issued and outstanding shares of Common Stock, which resulted in the Reporting Person's ownership of issued and outstanding Common Stock being increased from 15,875 shares of Common Stock to 19,843 shares of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Jennifer L. Deacon</signatureName>
        <signatureDate>2023-05-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
