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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-09-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001210708</issuerCik>
        <issuerName>Hudson Global, Inc.</issuerName>
        <issuerTradingSymbol>HSON</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001423385</rptOwnerCik>
            <rptOwnerName>Sagard Capital Partners, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>325 GREENWICH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001423386</rptOwnerCik>
            <rptOwnerName>Sagard Capital Partners Management Corp</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>325 GREENWICH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>2ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001423388</rptOwnerCik>
            <rptOwnerName>Sagard Capital Partners GP, Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>325 GREENWICH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2016-09-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1100000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3191584</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>SEE FOOTNOTE</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Consists of shares of common stock, par value, $0.001 per share, of HSON (&quot;Shares&quot;).</footnote>
        <footnote id="F2">Sagard is the direct beneficial owner of the Shares reported herein.  GP and Sagard Management are indirect beneficial owners of such Shares.  Each of the Reporting Persons disclaims beneficial ownership (as defined in Rule 16a-1(a)(2)) of the securities reported herein except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F3">The sale transaction reported on this Form 4 is pursuant to a Securities Purchase Agreement, dated as of September 6, 2016, by and between Sagard and the Issuer.  Subject to the satisfaction of the conditions set forth therein, it is expected that the sale transaction contemplated thereby will be consummated on or before September 9, 2016.</footnote>
    </footnotes>

    <remarks>This Form 4 is being filed by Sagard Capital Partners, L.P., a Delaware limited partnership (&quot;Sagard&quot;), Sagard Capital Partners GP, Inc., a Delaware corporation (&quot;GP&quot;), and Sagard Capital Partners Management Corp., a Delaware corporation (&quot;Sagard Management,&quot; and together with Sagard and GP, the &quot;Reporting Persons&quot;).  As a result of direct and indirect securities holdings, Power Corporation of Canada and The Desmarais Family Residuary Trust (the &quot;Trust&quot;), which was formed under the Last Will and Testament of Paul G. Desmarais, may be deemed (i) to control the Reporting Persons, although the filing of this Form 4 shall not be construed as an admission that any such control relationship actually exists, and (ii) to beneficially own the securities reported herein.  Each of Power Corporation of Canada and the Trust and the trustees of the Trust disclaims beneficial ownership of the securities reported herein except to the extent of its pecuniary interest therein, if any.</remarks>

    <ownerSignature>
        <signatureName>/s/ Charles J. Downey III, Attorney-in-Fact for Sagard Capital Partners, L.P.</signatureName>
        <signatureDate>2016-09-08</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Charles J. Downey III, Attorney-in-Fact for Sagard Capital Partners GP, Inc.</signatureName>
        <signatureDate>2016-09-08</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Charles J. Downey III, Attorney-in-Fact for Sagard Capital Partners Management Corp.</signatureName>
        <signatureDate>2016-09-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
