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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-04-22</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001724979</issuerCik>
        <issuerName>Rain Therapeutics Inc.</issuerName>
        <issuerTradingSymbol>RAIN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001465914</rptOwnerCik>
            <rptOwnerName>Davis Aaron I.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O RAIN THERAPEUTICS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>8000 JARVIS AVENUE, SUITE 204</rptOwnerStreet2>
            <rptOwnerCity>NEWARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94560</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001468223</rptOwnerCik>
            <rptOwnerName>MVA Investors, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12860 EL CAMINO REAL, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3263986</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>86097</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Series B Preferred Stock is convertible into common stock on a one-for-1.0799 basis into the number of shares of common stock shown in column 3 at any time at the holder's election and will convert automatically upon the closing of the Issuer's initial public offering.  The Series B Preferred Stock has no expiration date.</footnote>
        <footnote id="F2">These securities are owned directly by Boxer Capital, LLC (&quot;Boxer Capital&quot;), which may be deemed to be a member of a &quot;group&quot; for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, consisting of (i) Boxer Capital, (ii) Boxer Asset Management Inc. (&quot;Boxer Management&quot;), (iii) MVA Investors, LLC (&quot;MVA Investors&quot;), (iv) Joe Lewis and (v) Aaron I. Davis (collectively, the &quot;Boxer Group&quot;), and indirectly by Boxer Management, Mr. Lewis and Mr. Davis by virtue of their ownership in Boxer Capital. Each member of the Boxer Group other than Boxer Capital disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein.</footnote>
        <footnote id="F3">These securities are owned directly by MVA Investors, which may be deemed to be a member of the Boxer Group for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, and indirectly by Mr. Davis who is a member of and has voting and dispositive power over securities held by MVA Investors. Each member of the Boxer Group other than MVA Investors disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein.</footnote>
    </footnotes>

    <remarks>Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Nelson Cabatuan, Attorney-in-fact for Aaron Davis</signatureName>
        <signatureDate>2021-04-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>MVA Investors, LLC, By: /s/ Aaron Davis, Aaron Davis, Chief Executive Officer</signatureName>
        <signatureDate>2021-04-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
