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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-05-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001082506</issuerCik>
        <issuerName>Great Elm Capital Group, Inc.</issuerName>
        <issuerTradingSymbol>GEC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001805378</rptOwnerCik>
            <rptOwnerName>Imperial Capital Asset Management, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10100 SANTA MONICA BLVD., SUITE 2400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001308057</rptOwnerCik>
            <rptOwnerName>LONG BALL PARTNERS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IMPERIAL CAPITAL ASSET MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>10100 SANTA MONICA BLVD., SUITE 2400</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001479613</rptOwnerCik>
            <rptOwnerName>Reese Jason W.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IMPERIAL CAPITAL ASSET MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>10100 SANTA MONICA BLVD., SUITE 2400</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2020-05-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.3478</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2329312</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock, par value $0.001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36517</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.25 to $2.38, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F2">The Common Stock is held directly by Long Ball Partners, LLC (&quot;Long Ball&quot;). Jason Reese is portfolio manager to Long Ball and is Chairman and Chief Executive Officer of Imperial Capital Asset Management, LLC (&quot;ICAM&quot;), which is the managing member and investment manager to Long Ball. Each of Mr. Reese and ICAM disclaims beneficial ownership of the securities held by Long Ball except to the extent of that person's pecuniary interest therein.</footnote>
        <footnote id="F3">Mr. Reese was awarded 36,517 restricted shares that vest commencing April 10, 2020, with 3,502 shares vesting immediately and of the remaining amount, one-twelfth vesting each monthly anniversary of such date, contingent upon continued service as a member of the board of directors of Great Elm Capital Group, Inc. Each of Long Ball and ICAM disclaims beneficial ownership of the securities held by Mr. Reese.</footnote>
    </footnotes>

    <remarks>Mr. Reese is a director and Executive Co-Chairman of the Issuer.
The Reporting Persons are jointly filing this Form 4.</remarks>

    <ownerSignature>
        <signatureName>Long Ball Partners, LLC, By: Imperial Capital Asset Management, LLC, its Managing Member, By: /s/ Jason Reese, Chairman &amp; CEO</signatureName>
        <signatureDate>2020-06-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Imperial Capital Asset Management, LLC, By: /s/ Jason Reese, Chairman &amp; CEO</signatureName>
        <signatureDate>2020-06-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Jason Reese, /s/ Jason Reese</signatureName>
        <signatureDate>2020-06-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
