Lee Tillman is chairman, president and CEO of Marathon Oil Corporation and chairman of the Marathon Oil Corporation Board of Directors. He joined the Company in August 2013.

Prior to joining Marathon Oil, Lee served as vice president of engineering for ExxonMobil Development Company (a project design and execution company), where he was responsible for all global engineering staff engaged in major project concept selection, front-end design and engineering. He served as North Sea production manager and lead country manager for subsidiaries of ExxonMobil in Stavanger, Norway, from 2007 and 2010, and as acting vice president, ExxonMobil Upstream Research Company from 2006 to 2007. Lee began his career in the oil and gas industry at Exxon Corporation in 1989 as a research engineer and has extensive operations management and leadership experience that has included assignments in Jakarta, Indonesia; Aberdeen, Scotland; Stavanger, Norway; Malabo, Equatorial Guinea; Dallas and New Orleans.

Lee sits on the board and the executive committee of both the American Petroleum Institute and the American Exploration & Production Council. He is a member of the Chemical Engineering and Engineering Advisory Councils of Texas A&M University and is a member of the National Petroleum Council and the Society of Petroleum Engineers. He serves on the board of directors of the Houston Area and Southwest Region of the American Heart Association and is a member of the Celebration of Reading Committee within the Barbara Bush Houston Literacy Foundation, and a member of the advisory board of Spindletop Charities

Lee earned a Bachelor of Science in chemical engineering from Texas A&M University and a Ph.D. in chemical engineering from Auburn University.