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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-09-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001596967</issuerCik>
        <issuerName>Moelis &amp; Co</issuerName>
        <issuerTradingSymbol>MC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001604686</rptOwnerCik>
            <rptOwnerName>MOELIS KENNETH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MOELIS &amp; COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>399 PARK AVENUE, 5TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
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            <securityTitle>
                <value>2014 Incentive RSUs Granted in 2015</value>
            </securityTitle>
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                <footnoteId id="F1"/>
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            <transactionDate>
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            <deemedExecutionDate></deemedExecutionDate>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>721.33</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
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                <transactionAcquiredDisposedCode>
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            <expirationDate>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
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            </underlyingSecurity>
            <postTransactionAmounts>
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                    <value>47694.52</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>2015 Incentive RSUs</value>
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                <value>0.00</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-09-27</value>
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            <deemedExecutionDate></deemedExecutionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
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            </transactionCoding>
            <transactionTimeliness>
                <value></value>
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            <transactionAmounts>
                <transactionShares>
                    <value>1364.04</value>
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                <transactionPricePerShare>
                    <value>0.00</value>
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                <transactionAcquiredDisposedCode>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
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                <underlyingSecurityShares>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>90190.03</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>2016 Incentive RSUs</value>
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            <conversionOrExercisePrice>
                <value>0.00</value>
                <footnoteId id="F1"/>
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            <transactionDate>
                <value>2019-09-27</value>
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            <deemedExecutionDate></deemedExecutionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1036.3</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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            <exerciseDate>
                <footnoteId id="F4"/>
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            <expirationDate>
                <footnoteId id="F4"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1036.3</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>68519.91</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>2017 Incentive RSUs</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-09-27</value>
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            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
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                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1124.5</value>
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                <transactionPricePerShare>
                    <value>0.00</value>
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                <transactionAcquiredDisposedCode>
                    <value>A</value>
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            <exerciseDate>
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            <expirationDate>
                <footnoteId id="F5"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1124.5</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>74351.68</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>2017 Long Term Incentive Award</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-09-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>203.21</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F6"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>203.21</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13436.41</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>2018 Incentive RSUs</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-09-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1659.05</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F7"/>
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            <expirationDate>
                <footnoteId id="F7"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1659.05</value>
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            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>109696.48</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B common stock, par value $0.01</value>
                <footnoteId id="F8"/>
                <footnoteId id="F9"/>
                <footnoteId id="F10"/>
                <footnoteId id="F11"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F8"/>
                <footnoteId id="F9"/>
                <footnoteId id="F10"/>
                <footnoteId id="F11"/>
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            <transactionDate>
                <value>2019-09-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>33507</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0186</value>
                    <footnoteId id="F12"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F8"/>
                <footnoteId id="F9"/>
                <footnoteId id="F10"/>
                <footnoteId id="F11"/>
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            <expirationDate>
                <footnoteId id="F8"/>
                <footnoteId id="F9"/>
                <footnoteId id="F10"/>
                <footnoteId id="F11"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock, par value $0.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>18</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10397915</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Partnership</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each Restricted Stock Unit (RSU) represents the right to receive upon settlement either, at Moelis &amp; Company's option, a share of Class A common stock or an amount of cash equal to the fair market value of such share.</footnote>
        <footnote id="F2">Incentive RSUs were issued as dividend equivalents on holder's unvested underlying Incentive RSUs issued on March 2, 2015 (and dividend equivalents thereon). The dividend equivalent Incentive RSUs will vest concurrently with the vesting of the unvested underlying Incentive RSUs.</footnote>
        <footnote id="F3">Incentive RSUs were issued as dividend equivalents on holder's unvested underlying Incentive RSUs issued on February 24, 2016 (and dividend equivalents thereon). The dividend equivalent Incentive RSUs will vest concurrently with the vesting of the unvested underlying Incentive RSUs.</footnote>
        <footnote id="F4">Incentive RSUs were issued as dividend equivalents on holder's unvested underlying Incentive RSUs issued on February 23, 2017 (and dividend equivalents thereon). The dividend equivalent Incentive RSUs will vest concurrently with the vesting of the unvested underlying Incentive RSUs.</footnote>
        <footnote id="F5">Incentive RSUs were issued as dividend equivalents on holder's unvested underlying Incentive RSUs issued on February 15, 2018 (and dividend equivalents thereon). The dividend equivalent Incentive RSUs will vest concurrently with the vesting of the unvested underlying Incentive RSUs.</footnote>
        <footnote id="F6">Long Term Incentive RSUs were issued as dividend equivalents on holder's unvested underlying Incentive RSUs issued on February 15, 2018 (and dividend equivalents thereon). The dividend equivalent Incentive RSUs will vest concurrently with the vesting of the unvested underlying Incentive RSUs.</footnote>
        <footnote id="F7">Incentive RSUs were issued as dividend equivalents on the holder's unvested underlying Incentive RSUs issued on February 14, 2019 (and dividend equivalents subsequently issued thereon). The dividend equivalent Incentive RSUs will vest concurrently with the vesting of the unvested underlying Incentive RSUs.</footnote>
        <footnote id="F8">Each share of Moelis &amp; Company (the &quot;Company&quot;) Class B common stock is convertible into approximately 0.00055 shares of Moelis &amp; Company Class A common stock in certain circumstances, including when and if certain holders of Moelis &amp; Company Group LP (&quot;Group LP&quot;) Class A partnership units elect to exchange such units for Moelis &amp; Company Class A common stock. Such conversions of Class B common stock may often result in conversion into less than 1 share of Class A common stock and in such case in lieu of such fractional share, Moelis &amp; Company will pay the holder (Moelis &amp; Company Partner Holdings LP) cash equal to the Value (as defined in the Company's Amended and Restated Certificate of Incorporation) of the fractional share of Class A common stock.</footnote>
        <footnote id="F9">In addition, upon the forfeiture or other retirement of Group LP Class A partnership units, Moelis &amp; Company generally will be required to repurchase a corresponding number of shares of Class B common stock from the holder at the Value (as defined in the Company's Amended and Restated Certificate of Incorporation) of the underlying Class A common stock into which such Class B common stock is convertible. The transactions reported on this Form 4 are repurchases as described in this Footnote (9).</footnote>
        <footnote id="F10">The transactions reported in this Form 4 were approved by the issuer's Board of Directors pursuant to Exchange Act Rule 16b-3.</footnote>
        <footnote id="F11">Conversions and repurchase transactions referred to in Footnotes (8) and (9) are expected to occur on a regular, periodic basis.</footnote>
        <footnote id="F12">Price per Class B share.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Osamu Watanabe as attorney-in-fact for Kenneth Moelis</signatureName>
        <signatureDate>2019-10-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
