<?xml version="1.0"?>
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    <periodOfReport>2021-02-23</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>
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            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, CEO</officerTitle>
        </reportingOwnerRelationship>
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                    <value>24854.13</value>
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    <footnotes>
        <footnote id="F1">Represents a transaction by the Moelis Family Trust. Mr. Moelis is a beneficiary of The Moelis Family Trust. Mr. Moelis shares voting and dispositive power over the assets of The Moelis Family Trust with Mrs. Julie Moelis.</footnote>
        <footnote id="F2">On February 23, 2021 certain of the holder's partnership interests (&quot;Partnership Interests&quot;) in Moelis &amp; Company Partner Holdings LP (&quot;Partner Holdings&quot;) were exchanged for an equal number of Class A partnership units (&quot;Group Units&quot;) in Moelis &amp; Company Group LP (&quot;Group LP&quot;) and the Group Units were exchanged for an equal number of shares of Moelis &amp; Company Class A common stock. The exchanges were approved by the Company's board of directors under Rule 16b-3. Partnership Interests became exchangeable for an equal number of Group Units, following the expiration of the lock-up restriction, which expired on April 22, 2020. Each Group Unit became exchangeable for a share of Moelis &amp; Company Class A common stock (subject to customary adjustments) or cash, at Group LP's option. The form of Group LP's agreement of limited partnership has been filed as an exhibit to Moelis &amp; Company's registration statement on Form S-1 (File No. 333194306) dated April 8, 2014.</footnote>
        <footnote id="F3">This number excludes (i) 450,579 units of unvested equity granted to Mr. Moelis as incentive compensation for fiscal years 2016 through 2020 and (ii) 4,076,314 shares of Class A common stock issuable in exchange for Group Units held by The Moelis Family Trust.</footnote>
        <footnote id="F4">The conversion covered by this footnote automatically occurred pursuant to the terms of the Company's Amended and Restated Certificate of Incorporation when certain Group Units were exchanged for Class A common stock by certain selling Stockholders.</footnote>
        <footnote id="F5">Shares of Class A Common Stock were acquired upon settlement of Restricted Stock Units (RSUs).</footnote>
        <footnote id="F6">Each share of Class B common stock is convertible into approximately 0.00055 shares of Class A common stock in certain circumstances, including when and if certain holders of Group Units elect to exchange such units for 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, the Company will pay the holder (Partner Holdings) 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="F7">The RSUs were settled for Class A Common Stock on February 23, 2021.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Osamu Watanabe as attorney-in-fact for Kenneth Moelis</signatureName>
        <signatureDate>2021-02-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
