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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-01-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001659323</issuerCik>
        <issuerName>Iterum Therapeutics plc</issuerName>
        <issuerTradingSymbol>ITRM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001247851</rptOwnerCik>
            <rptOwnerName>HUNT RONALD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ITERUM THERAPEUTICS PLC, BLK 2</rptOwnerStreet1>
            <rptOwnerStreet2>FL. 3, HARCOURT CENTRE, HARCOURT ST.</rptOwnerStreet2>
            <rptOwnerCity>DUBLIN</rptOwnerCity>
            <rptOwnerState>L2</rptOwnerState>
            <rptOwnerZipCode>2</rptOwnerZipCode>
            <rptOwnerStateDescription>IRELAND</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>6.500% Exchangeable Senior Subordinated Note due 2025</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-01-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>2208000.00</value>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <value>2208000.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-01-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2208000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>2208000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By New Leaf Ventures III, L.P.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>6.500% Exchangeable Senior Subordinated Note due 2025</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-01-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>792000.00</value>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <value>792000.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-01-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>792000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>792000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By New Leaf Biopharma Opportunities II, L.P.</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On January 21, 2020, Iterum Therapeutics Bermuda Limited (the &quot;Issuer&quot;), a wholly-owned subsidiary of Iterum Therapeutics plc (the &quot;Company&quot;), issued and sold, among other things, 6.500% exchangeable senior subordinated notes due 2025 (the &quot;Exchangeable Notes&quot;) pursuant to a securities purchase agreement among the Issuer, the Company, the Company's wholly-owned subsidiaries and a group of accredited investors. The Exchangeable Notes are exchangeable into, at the Company's election, Ordinary Shares of the Company, cash or a combination of Ordinary Shares and cash, at an initial exchange rate of 1,000 shares per $1,000 principal amount of Exchangeable Notes (equivalent to an initial exchange price of approximately $1.00 per Ordinary Share), subject to anti-dilution adjustments as set forth in the indenture governing the Exchangeable Notes.</footnote>
        <footnote id="F2">(Continued from Footnote 1) Subject to the terms of the indenture governing the Exchangeable Notes, on or after January 21, 2021 until the second scheduled trading day immediately preceding January 15, 2025, holders may exchange the Exchangeable Notes at any time.  The Exchangeable Notes mature on January 31, 2025, unless earlier exchanged, redeemed or repurchased in accordance with their terms.</footnote>
        <footnote id="F3">The Exchangeable Note is held directly by New Leaf Ventures III, L.P. (&quot;NLV-III&quot;). New Leaf Venture Associates III, L.P. (&quot;NLVA-III LP&quot;) is the general partner of NLV-III and New Leaf Venture Management III, L.L.C. (&quot;NLVM-III LLC&quot;) is the general partner of NLVA-III LP, and each of NLVA-III LP and NLVM-III LLC may be deemed to have sole voting, investment and dispositive power with respect to the Exchangeable Note held by NLV-III. The Reporting Person, a member of the Company's Board of Directors, is a managing director of NLVM-III LLC and, in his capacity as a managing director, may be deemed to have shared voting, investment and dispositive power with respect to the Exchangeable Note held by NLV-III. The Reporting Person disclaims Section 16 beneficial ownership of the securities held by NLV-III, except to the extent of his pecuniary interest therein, if any.</footnote>
        <footnote id="F4">The Exchangeable Note is held directly by New Leaf Biopharma Opportunities II, L.P. (&quot;NBPO-II&quot;). New Leaf BPO Associates II, L.P. (&quot;NBPO-IIA&quot;) is the general partner of NBPO-II and New Leaf BPO Management II, L.L.C. (&quot;NBPO-IIM&quot;) is the general partner of NBPO-IIA, and each of NBPO-IIA and NBPO-IIM may be deemed to have sole voting, investment and dispositive power with respect to the Exchangeable Note held by NBPO-II. The Reporting Person, a member of the Company's Board of Directors, is a managing director of NBPO-IIM and, in his capacity as a managing director, may be deemed to have shared voting, investment and dispositive power with respect to the Exchangeable Note held by NBPO-II. The Reporting Person disclaims Section 16 beneficial ownership of the securities held by NBPO-II, except to the extent of his pecuniary interest therein, if any.</footnote>
    </footnotes>

    <remarks>Exhibit Index: 24.1 Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Craig Slutzkin, attorney-in-fact for Ronald M. Hunt</signatureName>
        <signatureDate>2020-01-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
