<SEC-DOCUMENT>0001567619-21-010962.txt : 20210521
<SEC-HEADER>0001567619-21-010962.hdr.sgml : 20210521
<ACCEPTANCE-DATETIME>20210521170616
ACCESSION NUMBER:		0001567619-21-010962
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210519
FILED AS OF DATE:		20210521
DATE AS OF CHANGE:		20210521

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Cooke Shane
		CENTRAL INDEX KEY:			0001524823

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35676
		FILM NUMBER:		21950088

	MAIL ADDRESS:	
		STREET 1:		TREASURY BUILDING LOWER GRAND CANAL ST.
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			00000

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PROTHENA CORP PUBLIC LTD CO
		CENTRAL INDEX KEY:			0001559053
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			L2
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		77 SIR JOHN ROGERSON'S QUAY, BLOCK C
		STREET 2:		GRAND CANAL DOCKLANDS
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			D02 VK60
		BUSINESS PHONE:		011-353-1-236-2500

	MAIL ADDRESS:	
		STREET 1:		77 SIR JOHN ROGERSON'S QUAY, BLOCK C
		STREET 2:		GRAND CANAL DOCKLANDS
		CITY:			DUBLIN 2
		STATE:			L2
		ZIP:			D02 VK60

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Prothena Corp plc
		DATE OF NAME CHANGE:	20121102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Neotope Corp Ltd
		DATE OF NAME CHANGE:	20120926
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-05-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001559053</issuerCik>
        <issuerName>PROTHENA CORP PUBLIC LTD CO</issuerName>
        <issuerTradingSymbol>PRTA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001524823</rptOwnerCik>
            <rptOwnerName>Cooke Shane</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PROTHENA BIOSCIENCES INC</rptOwnerStreet1>
            <rptOwnerStreet2>331 OYSTER POINT BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>SOUTH SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>23.97</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-05-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-05-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares subject to the option will vest and become exercisable as to 100% of the total number of shares subject to the option on the earlier of the first anniversary of the grant date or the day of the annual general meeting in 2022 of the Issuer's shareholders, assuming continuous service as a director until such vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Michael J. Malecek, as attorney-in-fact for Shane M. Cooke</signatureName>
        <signatureDate>2021-05-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
