Maryann Mannen

Chairman, President and Chief Executive Officer Marathon Petroleum

Last Reviewed: October 1, 2026

Executive Summary

Maryann Mannen has been Marathon Petroleum’s President and Chief Executive Officer since August 2024 and became Chairman in January 2026. She also leads MPLX, the company’s midstream partnership, as President and CEO and, since January 2026, chairman. A finance executive by background, she spent more than three decades at FMC Technologies and its successor TechnipFMC, rising to chief financial officer, before joining Marathon Petroleum as CFO in 2021 and becoming President in 2024. She chairs the American Petroleum Institute. Marathon Petroleum ranked No. 30 on the 2026 Fortune 500.

Career Highlights

• Chairman of Marathon Petroleum since January 2026; President and Chief Executive Officer since August 2024.
• President and CEO of MPLX since August 2024; Chairman since January 2026.
• Executive Vice President and Chief Financial Officer of Marathon Petroleum, 2021 to 2023.
• Chief Financial Officer of FMC Technologies and TechnipFMC.
• Chairman of the American Petroleum Institute.

Professional Journey

Mannen joined FMC Technologies in 1986 and held positions of increasing responsibility, becoming Senior Vice President and Chief Financial Officer in 2011 and Executive Vice President and CFO in 2014. From 2017 she was Executive Vice President and Chief Financial Officer of TechnipFMC, its successor.

She joined Marathon Petroleum as Executive Vice President and Chief Financial Officer in January 2021 and joined MPLX’s board the following month. She became President in January 2024 and President and Chief Executive Officer of both Marathon Petroleum and MPLX in August 2024, when she also joined Marathon Petroleum’s board.

In January 2026 she was elected Chairman of both boards. She chairs the American Petroleum Institute, sits on the executive committees of American Fuel and Petrochemical Manufacturers and the Ohio Business Roundtable, and is a member of The Business Council.

Education

No first-party source read for this profile states her education.