Trinseo PLC 8-K

What Happened Trinseo PLC filed an 8-K on July 17, 2026, announcing its annual general meeting of shareholders will be held on September 23, 2026 at 8:30 a.m. EST. Shareholders of record as of July 30, 2026 will be eligible to vote. The meeting will take place at Trinseo’s headquarters (440 East Swedesford Road, Suite 301, Wayne, Pennsylvania 19087), and shareholders in Ireland may participate by audio/video link at McCann FitzGerald LLP, Riverside One, Sir John Rogerson's Quay, Grand Canal Dock, Dublin 2, D02 X576.

Key Details

• Meeting date/time: September 23, 2026 at 8:30 a.m. EST.
• Record date (eligible voters): July 30, 2026.
• Primary location: 440 East Swedesford Road, Suite 301, Wayne, PA 19087; Irish participation site: McCann FitzGerald LLP, Dublin.
• Registration: Shareholders who plan to attend must register in advance; additional registration and attendance details will be provided in the proxy statement.

Why It Matters The annual general meeting is when shareholders vote on matters such as director elections and other proposals disclosed in the proxy statement. The filing sets the official meeting and record dates investors use to determine voting eligibility and plan participation. Trinseo’s proxy statement (to be issued) will provide the agenda, voting materials and registration instructions — important for shareholders who want to vote or attend (including remote participation for Irish shareholders). The 8-K was signed by Angelo Chaclas, Senior Vice President and Chief Legal Officer, on July 17, 2026.