AVIENT CORP

Even if you plan to attend and participate in our Annual Meeting, please cast your vote as soon as possible using one of the following advance voting methods:

Visit www.proxyvote.com to vote your proxy over the internet until 11:59 p.m. (ET) on May 13, 2026.

Call +1-800-690-6903 to vote your proxy by telephone until 11:59 p.m. (ET) on May 13, 2026.

Sign, date and return your proxy card and/or voting instruction card to vote by mail.

Common shares represented by a properly signed proxy card will be voted in accordance with the choices marked on the card. If no choices are marked, the shares will be voted FOR the: (1) election of eleven Director nominees to our Board; (2) approval, on an advisory basis, of Named Executive Officer compensation; and (3) ratification of the appointment of Ernst & Young LLP (“EY”) as our independent registered public accounting firm for the fiscal year ending December 31, 2026.

Each shareholder’s vote is important. Please submit your vote and proxy by internet or telephone, or complete, sign, date and return your proxy card or voting instruction card.

PROXY STATEMENT 2026 | Annual Meeting of Shareholders 2