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

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    <periodOfReport>2021-07-16</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001752828</issuerCik>
        <issuerName>Celularity Inc</issuerName>
        <issuerTradingSymbol>CELU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001752834</rptOwnerCik>
            <rptOwnerName>GX Sponsor LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1325 AVENUE OF THE AMERICAS, 25TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

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            <deemedExecutionDate></deemedExecutionDate>
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                <transactionFormType>4</transactionFormType>
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                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
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                    <value>7187500</value>
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            <securityTitle>
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        <derivativeTransaction>
            <securityTitle>
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                <transactionPricePerShare>
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            <transactionTimeliness>
                <value></value>
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                <transactionShares>
                    <value>7000000</value>
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                <transactionPricePerShare>
                    <footnoteId id="F8"/>
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                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <footnoteId id="F7"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7000000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On July 16, 2021, in connection with the consummation of the business combination (the &quot;Business Combination&quot;) among GX Acquisition Corp. (&quot;GX&quot;), Alpha First Merger Sub Corp., Celularity LLC and Celularity Inc., pursuant to that certain Merger Agreement and Plan of Merger and Reorganization, dated January 8, 2021, each share of Class B common stock of GX held by GX Sponsor LLC (&quot;Sponsor&quot;) automatically converted into one share of Class A common stock (&quot;Common Stock&quot;) of Celularity Inc., formerly known as GX Acquisition Corp. (the &quot;Issuer&quot;).</footnote>
        <footnote id="F2">25% of the shares are subject to vesting. Such shares shall vest on the first day that the volume weighted average price of the Common Stock on Nasdaq is at or above $12.00 for 20 trading days over a 30 consecutive trading day period immediately preceding such day. Shares that do not vest by July 15, 2031 will be forfeited.  Vesting is subject to acceleration upon certain change of control events at the Issuer.</footnote>
        <footnote id="F3">Sponsor is the record holder of these securities. Cooper Road, LLC (an entity controlled by Jay R. Bloom) and Dean C. Kehler are the managing members of Sponsor, and as such Messrs. Bloom and Kehler have voting and investment discretion with respect to the securities held of record by Sponsor and may be deemed to have shared beneficial ownership of the securities held directly by Sponsor. Each such entity or person disclaims any beneficial ownership of the reported securities other than to the extent of any pecuniary interest they may have therein, directly or indirectly.</footnote>
        <footnote id="F4">Represents a pro rata distribution of Common Stock to direct and indirect members of Sponsor.</footnote>
        <footnote id="F5">Reflects warrants of the Issuer (&quot;Private Warrants&quot;), which were acquired from the Issuer at a price of $1.00 per warrant in a private placement that closed simultaneously with the closing of the Issuer's initial public offering. These Private Warrants were later exchanged for warrants having the same terms, except that they are non-transferable other than to permitted transferees. Pursuant to the terms of the issuance, such warrants were not eligible to become exercisable unless the Issuer consummated its initial business combination, which occurred on July 16, 2021.</footnote>
        <footnote id="F6">The warrants will become exercisable 30 days after the completion of the Business Combination.</footnote>
        <footnote id="F7">The warrants will expire on the fifth anniversary of the completion of the Business Combination.</footnote>
        <footnote id="F8">Represents a pro rata distribution of Private Warrants to direct and indirect members of Sponsor.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jay R. Bloom, Authorized Signatory</signatureName>
        <signatureDate>2021-07-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
