Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo PLC (Exact name of registrant as specified in its charter) Ireland N/A (State or other juri ...

Trinseo PLC (NYSE:TSE) Q3 2023 Earnings Conference Call November 6, 2023 10:00 AM ET Company Participants Andy Myers - Finance Director, Corporate FP&A and IR Frank Bozich - President, CEO & Director David Stasse - EVP, CFO & Interim Principal Accounting Officer Conference Call Participants Frank Mitsch - Fermium Research, LLC David Begleiter - Deutsche Bank Matthew Blair - Tudor, Pickering, Holt & Co. Michael Leithead - Barclays Hassan Ahmed - Alembic Global Advisors Laurence Alexander - Jefferies Operat ...

Trinseo PLC (NYSE:TSE) Q2 2023 Earnings Conference Call August 4, 2023 10:00 AM ET Company Participants Andrew Myers - Finance Director, Corporate FP&A and IR Frank Bozich - President, CEO & Director David Stasse - EVP, CFO & Interim Principal Accounting Officer Conference Call Participants Frank Mitsch - Fermium Research Michael Leithead - Barclays Bank David Begleiter - Deutsche Bank Laurence Alexander - Jefferies Matthew Blair - Tudor, Pickering, Holt & Co. Roger Spitz - Bank of America Merrill Lynch Has ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo PLC (Exact name of registrant as specified in its charter) Ireland N/A (State or other jurisdict ...

Trinseo PLC (NYSE:TSE) Q1 2023 Earnings Conference Call May 5, 2023 10:00 AM ET Company Participants Andy Myers - Director, Investor Relations Frank Bozich - President & Chief Executive Officer David Stasse - Executive Vice President & Chief Financial Officer Conference Call Participants Stefan Diaz - Morgan Stanley Kevin Estok - Jefferies Priya Ranjan - RBC Operator Good morning, ladies and gentlemen, and welcome to the Trinseo First Quarter 2023 Financial Results Conference Call. We welcome the Trinseo m ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo PLC (Exact name of registrant as specified in its charter) Ireland N/A (State or other jurisdic ...

First Quarter 2023 Financial Results & Full-Year Outlook May 4, 2023 ™Trademark of Trinseo PLC or its affiliates Introductions & Disclosure Rules Introductions • Frank Bozich, President & CEO • David Stasse, Executive Vice President & CFO • Andy Myers, Director of Investor Relations Disclosure Rules This press release may contain forward-looking statements including, without limitation, statements concerning plans, objectives, goals, projections, forecasts, strategies, future events or performance, and unde ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36473 Trinseo PLC (Exact name of registrant as specified in its charter) Ireland N/A (State or other jurisdiction of (I.R.S. Em ...

Trinseo PLC (NYSE:TSE) Q4 2022 Results Conference Call February 9, 2023 10:00 AM ET Company Participants Andy Myers - Finance Director of Corporate FP&A and IR Frank Bozich - President, CEO and Director David Stasse - Executive VP and CFO Conference Call Participants Matthew Blair - TPH Frank Mitsch - Fermium Research David Begleiter - Deutsche Bank Michael Leithead - Barclays Dan Rizzo - Jefferies Stefan Diaz - Morgan Stanley Hassan Ahmed - Alembic Global Investors Eric Petrie - Citi Operator Good morning, ...

Third Quarter 2022 Financial Results & Full-Year 2022 Outlook November 2, 2022 ™Trademark of Trinseo PLC or its affiliates Introductions & Disclosure Rules Introductions • Frank Bozich, President & CEO • David Stasse, Executive Vice President & CFO • Andy Myers, Director of Investor Relations Disclosure Rules Cautionary Note on Forward-Looking Statements.This presentation may contain forward-looking statements including, without limitation, statements concerning plans, objectives, goals, projections, foreca ...