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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-10-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001289848</issuerCik>
        <issuerName>Huron Consulting Group Inc.</issuerName>
        <issuerTradingSymbol>[HURN]</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001173720</rptOwnerCik>
            <rptOwnerName>HCG HOLDINGS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>676 N. MICHIGAN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001305693</rptOwnerCik>
            <rptOwnerName>Lake Partners LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>676 N. MICHIGAN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001305694</rptOwnerCik>
            <rptOwnerName>Lake Capital Investment Partners LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>676 N. MICHIGAN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001187668</rptOwnerCik>
            <rptOwnerName>LAKE CAPITAL PARTNERS LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>676 N. MICHIGAN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001305710</rptOwnerCik>
            <rptOwnerName>Lake Capital Management LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>676 N. MICHIGAN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001183580</rptOwnerCik>
            <rptOwnerName>YOVOVICH PAUL G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LAKE CAPITAL MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>676 NORTH MICHIGAN AVENUE, SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001072744</rptOwnerCik>
            <rptOwnerName>GRAUNKE TERENCE M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LAKE CAPITAL MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>676 NORTH MICHIGAN AVENUE, SUITE 3900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60611</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>2004-10-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>750000</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8864576</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">HCG Holdings LLC directly owns 9,614,576 shares of common stock.  Lake Capital Partners LP and Lake Capital Management LLC are members of HCG Holdings LLC and collectively have investment and voting control over the shares of Common Stock held by HCG Holdings LLC. Lake Capital Investment Partners LP is the sole general partner of Lake Capital Partners LP and Lake Partners LLC is the sole general partner of Lake Capital Investment Partners LP.</footnote>
        <footnote id="F2">Terence M. Graunke and Paul G. Yovovich are the members and managers of Lake Partners LLC as well as members of an investment committee of Lake Capital Investment Partners LP and, in such roles, these individuals have investment and voting control over, and may be deemed to be the beneficial owners of, the shares ultimately controlled by Lake Capital Investment Partners LP. Mr. Graunke is also the controlling member of Lake Capital Management LLC and, pursuant to the Lake Capital Management LLC operating agreement, has investment and voting control over, and may be deemed to be the beneficial owner of, the shares controlled by that entity.</footnote>
        <footnote id="F3">Information with respect to each of the Reporting Persons is given solely by such Reporting Persons, and no Reporting Person has responsibility for the accuracy or completeness of information supplied by another Reporting Person. Any disclosures made hereunder with respect to persons other than the Reporting Persons are made on information and belief after making appropriate inquiry.</footnote>
        <footnote id="F4">Pursuant to Rule 16a-1(4) promulgated under the Securities Exchange Act of 1934, as amended, each of the Reporting Persons herein states that this filing shall not be deemed an admission that he or it is the beneficial owner of any of the shares of Common Stock covered by this Statement. Each of Lake Capital Partners LP, Lake Capital Management LLC, Lake Capital Investment Partners LP, Lake Partners  LLC, Messrs. Terence M. Graunke and Paul G. Yovovich disclaims beneficial ownership of the Common Stock, except to the extent of his or its pecuniary interest in such shares of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Paul G. Yovovich, on behalf of HCG Holdings LLC as Reporting Person</signatureName>
        <signatureDate>2004-10-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>(Please see Joint Filer Information for signatures of other Reporting Persons)</signatureName>
        <signatureDate>2004-10-22</signatureDate>
    </ownerSignature>
</ownershipDocument>

