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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2018-10-18</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001664106</issuerCik>
        <issuerName>LogicBio Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>LOGC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001568077</rptOwnerCik>
            <rptOwnerName>Kariv Tomer</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LOGICBIO THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>610 MAIN ST., 3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02139</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Convertible 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>674431</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Pontifax Investment Fund</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Convertible 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>364643</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Pontifax Investment Fund</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Convertible 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>328339</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Pontifax Investment Fund</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Series B Convertible Preferred Stock is convertible into shares of common stock at any time at the holder's election and automatically upon the consummation of a qualified public offering of the registrant. There is no expiration date for the Series B Convertible Preferred Stock.</footnote>
        <footnote id="F2">Represents shares of the Issuer held by Pontifax (Israel) IV, L.P. (&quot;Israel IV&quot;). Pontifax IV GP L.P. (&quot;Pontifax IV&quot;) is the general partner of Israel IV. Pontifax Management 4 G.P. (2015) Ltd. (&quot;Management 4&quot;) is the general partner of Pontifax IV. The Reporting Person is a Managing Partner of Management 4. By virtue of this relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by Israel IV. The Reporting Person disclaims beneficial ownership, within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), or otherwise of such portion of these securities in which he has no pecuniary interest.</footnote>
        <footnote id="F3">Represents shares of the Issuer held by Pontifax (China) IV, L.P. (&quot;China IV&quot;). Pontifax IV is the general partner of China IV. Management 4 is the general partner of Pontifax IV. By virtue of this relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by China IV. The Reporting Person disclaims beneficial ownership, within the meaning of Section 16 of the Exchange Act or otherwise of such portion of these securities in which he has no pecuniary interest.</footnote>
        <footnote id="F4">Represents shares of the Issuer held by Pontifax (Cayman) IV, L.P. (&quot;Cayman IV&quot;). Pontifax IV is the general partner of Cayman IV. Management 4 is the general partner of Pontifax IV. By virtue of this relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by Cayman IV. The Reporting Person disclaims beneficial ownership, within the meaning of Section 16 of the Exchange Act or otherwise of such portion of these securities in which he has no pecuniary interest.</footnote>
    </footnotes>

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

    <ownerSignature>
        <signatureName>/s/ Matthias Jaffe, as Attorney-In-Fact</signatureName>
        <signatureDate>2018-10-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
