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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>As filed with the Securities and Exchange Commission on August 8, 2024 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Registration <FONT STYLE="white-space:nowrap">No.&nbsp;333-&#8195;&#8195;</FONT> </B></P>
  <P STYLE="font-size:4pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
  <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT
  STYLE="white-space:nowrap">S-8</FONT></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>REGISTRATION STATEMENT </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>UNDER </I></B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B><I>THE
  SECURITIES ACT OF 1933 </I></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>Prothena Corporation Public Limited Company </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact name of registrant as specified in its charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:8pt" ALIGN="center">
  
  
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  <TD VALIGN="top" ALIGN="center"><B>Ireland</B></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">98-1111119</FONT></B></TD></TR>
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  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or other jurisdiction of</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>incorporation or organization)</B></P></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(IRS Employer</B></P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Identification No.)</B></P></TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>77 Sir John Rogerson&#146;s Quay, Block C </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Grand Canal Docklands </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Dublin 2, D02 VK60, Ireland </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Address of Principal Executive Offices, including Zip Code) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Prothena Corporation plc 2018 Long Term Incentive Plan, as amended </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Full title of the plan) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Michael J. Malecek </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Chief Legal Officer and Company Secretary </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Prothena Corporation plc </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>c/o Prothena Biosciences Inc </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>1800 Sierra Point Parkway </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Brisbane, California 94005 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(650) <FONT STYLE="white-space:nowrap">837-8550</FONT></B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Name, address, including zip code, and telephone number, including area code, of agent for service) </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><I>Copy to: </I></B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Sharon
  Flanagan </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Sidley Austin LLP </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>555 California Street, Suite 2000 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>San Francisco, California 94104 </B></P>
  <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(415) <FONT STYLE="white-space:nowrap">772-1271</FONT></B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
  <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether
  the registrant is a large accelerated filer, an accelerated filer, a <FONT STYLE="white-space:nowrap">non-accelerated</FONT> filer, a smaller reporting company or an emerging growth company. See the definitions of &#147;large accelerated
  filer,&#148; &#147;accelerated filer,&#148; &#147;smaller reporting company,&#148; and &#147;emerging growth company&#148; in Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Exchange Act. </P>
  <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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  <TD VALIGN="bottom">Large&nbsp;accelerated&nbsp;filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9746;</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Accelerated&nbsp;filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD></TR>
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  <TD VALIGN="bottom">Non-accelerated filer</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Smaller&nbsp;reporting&nbsp;company</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD></TR>
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  <TD VALIGN="bottom">&nbsp;</TD>
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  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom">Emerging&nbsp;growth&nbsp;company</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="bottom">&#9744;</TD></TR>
  </TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
  for complying with any new or revised financial accounting standards provided pursuant to Section&nbsp;7(a)(2)(B) of the Securities Act.&#8194;&#9744; </P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>PART I. INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The information called for in Part I of Form <FONT STYLE="white-space:nowrap">S-8</FONT> is not being filed with or included in this Form <FONT
  STYLE="white-space:nowrap">S-8</FONT> (by incorporation by reference or otherwise) in accordance with the rules and regulations of the Securities and Exchange Commission (the &#147;Commission&#148;). This Registration Statement on Form <FONT
  STYLE="white-space:nowrap">S-8</FONT> is filed by Prothena Corporation plc (the &#147;Registrant&#148;) regarding the Prothena Corporation plc 2018 Long Term Incentive Plan, as amended (the &#147;Plan&#148;). Documents containing the information
  required by Part I of the Registration Statement will be sent or given to participants in the Plan as specified by Rule 428(b)(1) under the Securities Act of 1933, as amended (the &#147;Securities Act&#148;). </P>
  <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>PART II. INFORMATION REQUIRED IN THE REGISTRATION STATEMENT </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;3. INCORPORATION OF DOCUMENTS BY REFERENCE </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The
  information incorporated by reference herein is considered to be part of this Registration Statement, and later information filed with the Commission will update and supersede this information. The following documents filed by the Registrant with
  the Commission are incorporated herein by reference: </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>(a)</B> The Registrant&#146;s Registration Statement on <A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000119312512411343/d411323d1012b.htm">Form
   10</A> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-35676)</FONT> filed with the Commission under Section&nbsp;12(b) of the Securities Exchange Act of 1934, as amended (the &#147;Exchange Act&#148;), on October&nbsp;1, 2012, including the
  description of the Registrant&#146;s ordinary shares contained therein, and any amendment or report filed for the purpose of updating such description, including <A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905324000008/prta2023xex42descriptionof.htm">Exhibit
   4.2</A> to the Company&#146;s Annual Report on Form <FONT STYLE="white-space:nowrap">10-K</FONT> for the year ended December&nbsp;31, 2023 and filed with the Commission on February&nbsp;22, 2024; </P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>(b)</B> The Registrant&#146;s Annual Report on Form <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000155905324000008/prta-20231231.htm">
  <FONT STYLE="white-space:nowrap">10-K</FONT></A> for the year ended December&nbsp;31, 2023, filed with the Commission on February&nbsp;22, 2024; </P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>(c)</B> The Registrant&#146;s Quarterly Report on Form <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000155905324000014/prta-20240331.htm">
  <FONT STYLE="white-space:nowrap">10-Q</FONT></A> for the quarter ended March&nbsp;31, 2024, filed with the Commission on May&nbsp;8, 2024; </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>(d) </B>The
  Registrant&#146;s Quarterly Report on Form <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000155905324000025/prta-20240630.htm"><FONT STYLE="white-space:nowrap">10-Q</FONT></A> for the quarter ended
  June<B></B><B></B>&nbsp;30, 2024, filed with the Commission on August 8, 2024; and </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>(e)</B> The Registrant&#146;s Current Reports on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000119312524003972/d707357d8k.htm">January&nbsp;
  8, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000155905324000005/prta-20240221.htm">February&nbsp;
  21, 2024</A>, <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000155905324000017/prta-20240514.htm">May&nbsp;
  17, 2024</A> and <A HREF="http://www.sec.gov/Archives/edgar/data/../../../ix?doc=/Archives/edgar/data/1559053/000155905324000019/prta-20240524.htm">May&nbsp;28, 2024</A>. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">All documents that the Registrant subsequently files pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a
  post-effective amendment to the Registration Statement which indicates that all of the ordinary shares offered have been sold or which deregisters all of such shares then remaining unsold shall be deemed to be incorporated by reference in this
  Registration Statement and to be a part hereof from the date of the filing of such documents, except as to any portion of any future annual or quarterly report to shareholders or document or current report furnished under Items 2.02 or 7.01 of Form <FONT
  STYLE="white-space:nowrap">8-K,</FONT> and exhibits furnished on such form that relate to such items, that is not deemed filed under such provisions. For the purposes of this Registration Statement, any statement contained in a document incorporated
  or deemed to be incorporated by reference herein shall be deemed to be modified or superseded to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference
  herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement. </P>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Under no circumstances will any information filed under current Items 2.02 or 7.01 of Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> be deemed incorporated herein by reference unless such Form <FONT STYLE="white-space:nowrap">8-K</FONT> expressly provides to the contrary. </P>
  <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;4. DESCRIPTION OF SECURITIES </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Not applicable.
  </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;5. INTERESTS OF NAMED EXPERTS AND COUNSEL </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Not applicable. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;6. INDEMNIFICATION OF DIRECTORS
  AND OFFICERS </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Under Irish law, a company may not exempt or indemnify its directors from liability for negligence or a breach of duty. However, where a
  breach of duty has been established, directors may be statutorily exempted by an Irish court from personal liability for negligence or breach of duty if, among other things, the court determines that they have acted honestly and reasonably, and that
  they may fairly be excused as a result. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Irish Companies Act 2014 (the &#147;Companies Act&#148;) permits a company to pay the costs or discharge the
  liability of a director or the secretary only where judgment is given in his/her favor in any civil or criminal action in respect of such costs or liability, or where an Irish court grants relief because the director or secretary acted honestly and
  reasonably and ought fairly to be excused. This restriction does not apply to executives who are not directors or the secretary. Any obligation of an Irish company that purports to indemnify a director or secretary of an Irish company over and above
  this will be void under Irish law, whether contained in its articles of association or any contract between the director or secretary and the company. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Registrant&#146;s Amended and Restated Memorandum and Articles of Association (the &#147;Constitution&#148;), which has been publicly filed with the
  Commission, provides, so far as is permitted under the Companies Act, that every director and the secretary shall be entitled to be indemnified by the Registrant against all costs, charges, losses, expenses and liabilities incurred by him or her in
  the execution and discharge of his or her duties or in relation thereto including any liability incurred by him or her in defending any proceedings, civil or criminal, which relate to anything done or omitted or alleged to have been done or omitted
  by him or her as an officer or employee of the Registrant and in which judgement is given in his or her favour (or the proceedings are otherwise disposed of without any finding or admission of any material breach of duty on his or her part) or in
  which he or she is acquitted or in connection with any application under any statute for relief from liability in respect of any such act or omission in which relief is granted to him or her by the court. </P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">In addition, the Constitution provides that the Registrant shall indemnify any of its current or former executives (excluding any directors or secretary), or
  any person who is serving or has served at the Registrant&#146;s request as a director, executive or trustee of another company, joint venture, trust or other enterprise (each, a &#147;Covered Person&#148;), against expenses, including
  attorneys&#146; fees, judgements, fines and amounts paid in settlement actually and reasonably incurred by him or her in connection with any threatened, pending, or completed action, suit or proceeding, whether civil, criminal, administrative or
  investigative, to which he or she was, is, or is threatened to be made a party, by reason of the fact that he or she is or was a Covered Person. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The
  directors and officers of the Registrant are covered by insurance policies indemnifying against certain liabilities, including certain liabilities arising under the Securities Act, which might be incurred by them in such capacities and against which
  they may not be indemnified by us. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Registrant has also entered into indemnification agreements with each of its directors and executive officers.
  These agreements, among other things, require the Registrant to indemnify an indemnitee to the fullest extent permitted by applicable law, including indemnification of expenses such as attorneys&#146; fees, judgments, fines and settlement amounts
  incurred by the indemnitee in any action or proceeding, arising out of the person&#146;s services as a director or executive officer. </P>
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   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;7. EXEMPTION FROM REGISTRATION CLAIMED </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Not applicable. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;8. EXHIBITS </B></P>
  <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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  <TD></TD>
  
  <TD VALIGN="bottom" WIDTH="5%"></TD>
  <TD WIDTH="92%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Exhibit</B><br><B>Number</B></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Description</B></P></TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.1</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905316000060/prta8-k2016agmexhibit31con.htm">Amended and Restated Memorandum and Articles of Association (Constitution) of Prothena Corporation plc.
  (1)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.2</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905318000017/a2018longtermincentiveplan.htm">Prothena Corporation plc 2018 Long Term Incentive Plan. (2)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.3</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905320000015/prta20208-kex101xfirstamen.htm">First Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (3)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.4</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905321000022/exhibit101prta-secondamend.htm">Second Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (4)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.5</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905322000026/exhibit101prta-thirdamendm.htm">Third Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (5)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.6</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000119312523149386/d467385dex101.htm">Fourth Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (6)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>4.7</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="http://www.sec.gov/Archives/edgar/data/1559053/000155905324000017/a2024mayxex101prtaxfiftham.htm">Fifth Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (7)&nbsp;</A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>5.1*</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d858159dex51.htm">Opinion of A&amp;L Goodbody. </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>23.1*</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d858159dex231.htm">Consent of KPMG LLP. </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>23.2*</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d858159dex51.htm">Consent of A&amp;L Goodbody (included in Exhibit 5.1). </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>24.1*</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="#sig">Power of Attorney (included on the signature page hereto). </A></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="8"></TD>
  <TD HEIGHT="8" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" NOWRAP>107*</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"><A HREF="d858159dexfilingfees.htm">Calculation of Filing Fee Table. </A></TD></TR>
  </TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">*</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Filed herewith. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(1)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 3.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;25, 2016. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(2)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 10.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;18, 2018. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(3)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 10.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;22, 2020. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(4)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 10.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;21, 2021. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(5)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 10.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;20, 2022. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(6)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 10.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;19, 2023. </P></TD></TR></TABLE>
  <TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
  <TR style = "page-break-inside:avoid">
  <TD WIDTH="4%" VALIGN="top" ALIGN="left">(7)</TD>
  <TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Incorporated by reference to Exhibit 10.1 of the Registrant&#146;s Current Report on Form <FONT
  STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on May&nbsp;17, 2024. </P></TD></TR></TABLE> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>ITEM&#8201;9. UNDERTAKINGS </B></P>
  <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1. The undersigned registrant hereby undertakes: </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(a) To file,
  during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement: </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(i) To include any prospectus
  required by Section&nbsp;10(a)(3) of the Securities Act; </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(ii) To reflect in the prospectus any facts or events arising after the effective date of the
  Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any
  increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in
  the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the &#147;Calculation of
  Registration Fee&#148; table in the effective Registration Statement; and </P>
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(iii) To include any material information with respect to the plan of distribution not previously disclosed
  in the Registration Statement or any material change to such information in the Registration Statement; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I>provided, however</I>, that paragraphs (a)(i)
  and (a)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section&nbsp;13 or
  Section&nbsp;15(d) of the Exchange Act that are incorporated by reference herein. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(b) That, for the purpose of determining any liability under the
  Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering
  thereof. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(c) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the
  termination of the offering. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">2. The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act,
  each filing of the registrant&#146;s annual report pursuant to Section&nbsp;13(a) or Section&nbsp;15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan&#146;s annual report pursuant to Section&nbsp;15(d) of the
  Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered herein, and the offering of such securities at that time shall be deemed to be the
  initial bona fide offering thereof. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">3. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers
  and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and
  is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the
  successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been
  settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.
  </P>
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  <Center><DIV STYLE="width:8.5in" align="left">
   <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SIGNATURES </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all
  of the requirements for filing on Form <FONT STYLE="white-space:nowrap">S-8</FONT> and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Brisbane, State of
  California, on August 8, 2024. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">
  
  
  <TR>
  
  <TD WIDTH="7%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="92%"></TD></TR>
  
  
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" COLSPAN="3"><B>PROTHENA CORPORATION PLC</B></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top">By:</TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Gene G. Kinney</P></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;</TD>
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Gene G. Kinney, Ph.D.</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">President, Chief
  Executive Officer and Director</P></TD></TR>
  </TABLE> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><A NAME="sig"></A>POWER OF ATTORNEY </B></P>
  <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Each person whose signature appears below constitutes and appoints Gene G. Kinney, Tran B. Nguyen and Michael J. Malecek, and each of them, as his or her true
  and lawful <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorney-in-fact</FONT></FONT> and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all
  capacities, to sign any and all amendments to this Registration Statement (including all post-effective amendments), and to file the same with all exhibits thereto, and other documents in connection therewith, with the Commission, granting unto said
  <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorney-in-fact</FONT></FONT> and agent full power and authority to do and perform each act and thing requisite and necessary to be done, as fully to all intents and purposes as he
  might or could do in person, hereby ratifying and confirming all that said <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">attorney-in-fact</FONT></FONT> and agent, or his substitute or substitutes, may lawfully do or cause to be
  done by virtue hereof. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the
  following persons in the capacities and on the dates indicated. </P>
  </DIV></Center>
  
  
  <p style="margin-top:1em; margin-bottom:0em; page-break-before:always"> </p>
  <HR SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">
  
  <Center><DIV STYLE="width:8.5in" align="left">
  
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">
  
  
  <TR>
  
  <TD WIDTH="42%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="40%"></TD>
  
  <TD VALIGN="bottom" WIDTH="1%"></TD>
  <TD WIDTH="16%"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
  <TD VALIGN="bottom" ALIGN="center">Signature</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center">Title</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="bottom" ALIGN="center">Date</TD></TR>
  
  
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Gene G. Kinney</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Gene G. Kinney, Ph.D.</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">President, Chief Executive Officer and Director</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">(Principal Executive Officer)</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Tran B. Nguyen</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Tran B. Nguyen</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Chief Strategy Officer and Chief Financial Officer</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">(Principal Financial Officer)</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:0pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Karin L. Walker</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Karin L. Walker</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Chief Accounting Officer</P>
  <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">(Principal Accounting Officer)</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Daniel G. Welch</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Chair of the Board</TD>
  <TD VALIGN="bottom" ROWSPAN="2">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ROWSPAN="2" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom" ALIGN="center">Daniel G. Welch</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Lars G. Ekman</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Chair Emeritus of the Board</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="bottom" ALIGN="center">Lars G. Ekman, M.D., Ph.D.</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Paula K. Cobb</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">Paula K. Cobb</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Richard T. Collier</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">Richard T. Collier</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Shane M. Cooke</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">Shane M. Cooke</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ William H. Dunn, Jr.</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">William H. Dunn, Jr., M.D.</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Helen S. Kim</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">Helen S. Kim</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Oleg Nodelman</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">Oleg Nodelman</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  <TR STYLE="font-size:1pt">
  <TD HEIGHT="16"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD>
  <TD HEIGHT="16" COLSPAN="2"></TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman" ALIGN="center">/s/ Dennis J. Selkoe</P></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="center">Director</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top" ALIGN="right">August 8, 2024</TD></TR>
  <TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
  <TD VALIGN="top" ALIGN="center">Dennis J. Selkoe, M.D.</TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD>
  <TD VALIGN="bottom">&nbsp;&nbsp;</TD>
  <TD VALIGN="top"></TD></TR>
  </TABLE>
  </DIV></Center>
  
  </BODY></HTML>
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "d858159ds8.htm", "description": "S-8", "secsgml_size_bytes": 54086}]
metadata_filer: {"company-data": {"conformed-name": "PROTHENA CORP PUBLIC LTD CO", "cik": "0001559053", "assigned-sic": "2834", "organization-name": "03 Life Sciences", "irs-number": "000000000", "state-of-incorporation": "L2", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-281407", "film-number": "241189607"}, "business-address": {"street1": "77 SIR JOHN ROGERSON'S QUAY, BLOCK C", "street2": "GRAND CANAL DOCKLANDS", "city": "DUBLIN 2", "state": "L2", "zip": "D02 VK60", "phone": "011-353-1-236-2500"}, "mail-address": {"street1": "77 SIR JOHN ROGERSON'S QUAY, BLOCK C", "street2": "GRAND CANAL DOCKLANDS", "city": "DUBLIN 2", "state": "L2", "zip": "D02 VK60"}, "former-company": [{"former-conformed-name": "Prothena Corp plc", "date-changed": "20121102"}, {"former-conformed-name": "Neotope Corp Ltd", "date-changed": "20120926"}]}
text: S-8
  As filed with the Securities and Exchange Commission on August 8, 2024
  Registration
  No. 333-
  UNITED STATES
  SECURITIES AND EXCHANGE COMMISSION
  Washington, D.C. 20549
  FORM
  S-8
  REGISTRATION STATEMENT
  UNDER
  THE
  SECURITIES ACT OF 1933
  Prothena Corporation Public Limited Company
  (Exact name of registrant as specified in its charter)
  Ireland
  98-1111119
  (State or other jurisdiction of
  incorporation or organization)
  (IRS Employer
  Identification No.)
  77 Sir John Rogerson's Quay, Block C
  Grand Canal Docklands
  Dublin 2, D02 VK60, Ireland
  (Address of Principal Executive Offices, including Zip Code)
  Prothena Corporation plc 2018 Long Term Incentive Plan, as amended
  (Full title of the plan)
  Michael J. Malecek
  Chief Legal Officer and Company Secretary
  Prothena Corporation plc
  c/o Prothena Biosciences Inc
  1800 Sierra Point Parkway
  Brisbane, California 94005
  (650)
  837-8550
  (Name, address, including zip code, and telephone number, including area code, of agent for service)
  Copy to:
  Sharon
  Flanagan
  Sidley Austin LLP
  555 California Street, Suite 2000
  San Francisco, California 94104
  (415)
  772-1271
  Indicate by check mark whether
  the registrant is a large accelerated filer, an accelerated filer, a
  non-accelerated
  filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated
  filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule
  12b-2
  of the Exchange Act.
  Large accelerated filer
  ☒
  Accelerated filer
  ☐
  Non-accelerated filer
  ☐
  Smaller reporting company
  ☐
  Emerging growth company
  ☐
  If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
  for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐
  PART I. INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS
  The information called for in Part I of Form
  S-8
  is not being filed with or included in this Form
  S-8
  (by incorporation by reference or otherwise) in accordance with the rules and regulations of the Securities and Exchange Commission (the "Commission"). This Registration Statement on Form
  S-8
  is filed by Prothena Corporation plc (the "Registrant") regarding the Prothena Corporation plc 2018 Long Term Incentive Plan, as amended (the "Plan"). Documents containing the information
  required by Part I of the Registration Statement will be sent or given to participants in the Plan as specified by Rule 428(b)(1) under the Securities Act of 1933, as amended (the "Securities Act").
  PART II. INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE
  The
  information incorporated by reference herein is considered to be part of this Registration Statement, and later information filed with the Commission will update and supersede this information. The following documents filed by the Registrant with
  the Commission are incorporated herein by reference:
  (a)
  The Registrant's Registration Statement on
  Form
   10
  (File
  No. 001-35676)
  filed with the Commission under Section 12(b) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), on October 1, 2012, including the
  description of the Registrant's ordinary shares contained therein, and any amendment or report filed for the purpose of updating such description, including
  Exhibit
   4.2
  to the Company's Annual Report on Form
  10-K
  for the year ended December 31, 2023 and filed with the Commission on February 22, 2024;
  (b)
  The Registrant's Annual Report on Form
  10-K
  for the year ended December 31, 2023, filed with the Commission on February 22, 2024;
  (c)
  The Registrant's Quarterly Report on Form
  10-Q
  for the quarter ended March 31, 2024, filed with the Commission on May 8, 2024;
  (d)
  The
  Registrant's Quarterly Report on Form
  10-Q
  for the quarter ended
  June
  30, 2024, filed with the Commission on August 8, 2024; and
  (e)
  The Registrant's Current Reports on Form
  8-K
  filed with the Commission on
  January 
  8, 2024
  ,
  February 
  21, 2024
  ,
  May 
  17, 2024
  and
  May 28, 2024
  .
  All documents that the Registrant subsequently files pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a
  post-effective amendment to the Registration Statement which indicates that all of the ordinary shares offered have been sold or which deregisters all of such shares then remaining unsold shall be deemed to be incorporated by reference in this
  Registration Statement and to be a part hereof from the date of the filing of such documents, except as to any portion of any future annual or quarterly report to shareholders or document or current report furnished under Items 2.02 or 7.01 of Form
  8-K,
  and exhibits furnished on such form that relate to such items, that is not deemed filed under such provisions. For the purposes of this Registration Statement, any statement contained in a document incorporated
  or deemed to be incorporated by reference herein shall be deemed to be modified or superseded to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference
  herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.
  Under no circumstances will any information filed under current Items 2.02 or 7.01 of Form
  8-K
  be deemed incorporated herein by reference unless such Form
  8-K
  expressly provides to the contrary.
  ITEM 4. DESCRIPTION OF SECURITIES
  Not applicable.
  ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL
  Not applicable.
  ITEM 6. INDEMNIFICATION OF DIRECTORS
  AND OFFICERS
  Under Irish law, a company may not exempt or indemnify its directors from liability for negligence or a breach of duty. However, where a
  breach of duty has been established, directors may be statutorily exempted by an Irish court from personal liability for negligence or breach of duty if, among other things, the court determines that they have acted honestly and reasonably, and that
  they may fairly be excused as a result.
  The Irish Companies Act 2014 (the "Companies Act") permits a company to pay the costs or discharge the
  liability of a director or the secretary only where judgment is given in his/her favor in any civil or criminal action in respect of such costs or liability, or where an Irish court grants relief because the director or secretary acted honestly and
  reasonably and ought fairly to be excused. This restriction does not apply to executives who are not directors or the secretary. Any obligation of an Irish company that purports to indemnify a director or secretary of an Irish company over and above
  this will be void under Irish law, whether contained in its articles of association or any contract between the director or secretary and the company.
  The Registrant's Amended and Restated Memorandum and Articles of Association (the "Constitution"), which has been publicly filed with the
  Commission, provides, so far as is permitted under the Companies Act, that every director and the secretary shall be entitled to be indemnified by the Registrant against all costs, charges, losses, expenses and liabilities incurred by him or her in
  the execution and discharge of his or her duties or in relation thereto including any liability incurred by him or her in defending any proceedings, civil or criminal, which relate to anything done or omitted or alleged to have been done or omitted
  by him or her as an officer or employee of the Registrant and in which judgement is given in his or her favour (or the proceedings are otherwise disposed of without any finding or admission of any material breach of duty on his or her part) or in
  which he or she is acquitted or in connection with any application under any statute for relief from liability in respect of any such act or omission in which relief is granted to him or her by the court.
  In addition, the Constitution provides that the Registrant shall indemnify any of its current or former executives (excluding any directors or secretary), or
  any person who is serving or has served at the Registrant's request as a director, executive or trustee of another company, joint venture, trust or other enterprise (each, a "Covered Person"), against expenses, including
  attorneys' fees, judgements, fines and amounts paid in settlement actually and reasonably incurred by him or her in connection with any threatened, pending, or completed action, suit or proceeding, whether civil, criminal, administrative or
  investigative, to which he or she was, is, or is threatened to be made a party, by reason of the fact that he or she is or was a Covered Person.
  The
  directors and officers of the Registrant are covered by insurance policies indemnifying against certain liabilities, including certain liabilities arising under the Securities Act, which might be incurred by them in such capacities and against which
  they may not be indemnified by us.
  The Registrant has also entered into indemnification agreements with each of its directors and executive officers.
  These agreements, among other things, require the Registrant to indemnify an indemnitee to the fullest extent permitted by applicable law, including indemnification of expenses such as attorneys' fees, judgments, fines and settlement amounts
  incurred by the indemnitee in any action or proceeding, arising out of the person's services as a director or executive officer.
  ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED
  Not applicable.
  ITEM 8. EXHIBITS
  Exhibit
  Number
  Description
  4.1
  Amended and Restated Memorandum and Articles of Association (Constitution) of Prothena Corporation plc.
  (1)
  4.2
  Prothena Corporation plc 2018 Long Term Incentive Plan. (2)
  4.3
  First Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (3)
  4.4
  Second Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (4)
  4.5
  Third Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (5)
  4.6
  Fourth Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (6)
  4.7
  Fifth Amendment to the Prothena Corporation plc 2018 Long Term Incentive Plan. (7)
  5.1*
  Opinion of A&L Goodbody.
  23.1*
  Consent of KPMG LLP.
  23.2*
  Consent of A&L Goodbody (included in Exhibit 5.1).
  24.1*
  Power of Attorney (included on the signature page hereto).
  107*
  Calculation of Filing Fee Table.
  *
  Filed herewith.
  (1)
  Incorporated by reference to Exhibit 3.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 25, 2016.
  (2)
  Incorporated by reference to Exhibit 10.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 18, 2018.
  (3)
  Incorporated by reference to Exhibit 10.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 22, 2020.
  (4)
  Incorporated by reference to Exhibit 10.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 21, 2021.
  (5)
  Incorporated by reference to Exhibit 10.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 20, 2022.
  (6)
  Incorporated by reference to Exhibit 10.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 19, 2023.
  (7)
  Incorporated by reference to Exhibit 10.1 of the Registrant's Current Report on Form
  8-K
  filed with the Commission on May 17, 2024.
  ITEM 9. UNDERTAKINGS
  1. The undersigned registrant hereby undertakes:
  (a) To file,
  during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:
  (i) To include any prospectus
  required by Section 10(a)(3) of the Securities Act;
  (ii) To reflect in the prospectus any facts or events arising after the effective date of the
  Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any
  increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in
  the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the "Calculation of
  Registration Fee" table in the effective Registration Statement; and
  (iii) To include any material information with respect to the plan of distribution not previously disclosed
  in the Registration Statement or any material change to such information in the Registration Statement;
  provided, however
  , that paragraphs (a)(i)
  and (a)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or
  Section 15(d) of the Exchange Act that are incorporated by reference herein.
  (b) That, for the purpose of determining any liability under the
  Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering
  thereof.
  (c) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the
  termination of the offering.
  2. The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act,
  each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the
  Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new registration statement relating to the securities offered herein, and the offering of such securities at that time shall be deemed to be the
  initial bona fide offering thereof.
  3. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers
  and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and
  is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the
  successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been
  settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.
  SIGNATURES
  Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all
  of the requirements for filing on Form
  S-8
  and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Brisbane, State of
  California, on August 8, 2024.
  PROTHENA CORPORATION PLC
  By:
  /s/ Gene G. Kinney
  Gene G. Kinney, Ph.D.
  President, Chief
  Executive Officer and Director
  POWER OF ATTORNEY
  Each person whose signature appears below constitutes and appoints Gene G. Kinney, Tran B. Nguyen and Michael J. Malecek, and each of them, as his or her true
  and lawful
  attorney-in-fact
  and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all
  capacities, to sign any and all amendments to this Registration Statement (including all post-effective amendments), and to file the same with all exhibits thereto, and other documents in connection therewith, with the Commission, granting unto said
  attorney-in-fact
  and agent full power and authority to do and perform each act and thing requisite and necessary to be done, as fully to all intents and purposes as he
  might or could do in person, hereby ratifying and confirming all that said
  attorney-in-fact
  and agent, or his substitute or substitutes, may lawfully do or cause to be
  done by virtue hereof.
  Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the
  following persons in the capacities and on the dates indicated.
  Signature
  Title
  Date
  /s/ Gene G. Kinney
  Gene G. Kinney, Ph.D.
  President, Chief Executive Officer and Director
  (Principal Executive Officer)
  August 8, 2024
  /s/ Tran B. Nguyen
  Tran B. Nguyen
  Chief Strategy Officer and Chief Financial Officer
  (Principal Financial Officer)
  August 8, 2024
  /s/ Karin L. Walker
  Karin L. Walker
  Chief Accounting Officer
  (Principal Accounting Officer)
  August 8, 2024
  /s/ Daniel G. Welch
  Chair of the Board
  August 8, 2024
  Daniel G. Welch
  /s/ Lars G. Ekman
  Chair Emeritus of the Board
  August 8, 2024
  Lars G. Ekman, M.D., Ph.D.
  /s/ Paula K. Cobb
  Director
  August 8, 2024
  Paula K. Cobb
  /s/ Richard T. Collier
  Director
  August 8, 2024
  Richard T. Collier
  /s/ Shane M. Cooke
  Director
  August 8, 2024
  Shane M. Cooke
  /s/ William H. Dunn, Jr.
  Director
  August 8, 2024
  William H. Dunn, Jr., M.D.
  /s/ Helen S. Kim
  Director
  August 8, 2024
  Helen S. Kim
  /s/ Oleg Nodelman
  Director
  August 8, 2024
  Oleg Nodelman
  /s/ Dennis J. Selkoe
  Director
  August 8, 2024
  Dennis J. Selkoe, M.D.