Exhibit

We consent to the incorporation by reference in the registration statements (Nos. 333-218184, 333-211653, 333-196572 and 333-187726) on Form S-8 and the registration statements (Nos. 333‑203258, 333-197006, 333-196965 and 333-193416) on Form S-3 of Prothena Corporation plc of our reports dated February 23, 2018 with respect to the consolidated balance sheets of Prothena Corporation plc as of December 31, 2017 and 2016, and the related consolidated statements of operations, shareholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2017, and the related notes (collectively, the “consolidated financial statements”), and the effectiveness of internal control over financial reporting as of December 31, 2017, which reports appear in the December 31, 2017 annual report on Form 10‑K of Prothena Corporation plc.