Alan Armstrong

Alan Armstrong was born on July 11, 1962, in McLennan County, Texas, and was raised in Bartlesville, Oklahoma. He earned a bachelor of science in civil engineering from the University of Oklahoma in 1985. In 1986 he joined Williams Companies in Tulsa as an engineer. His Senate biography says he was the company's vice president of gathering and processing from 1999 to 2002, became president and chief executive in 2011, and held that post through 2025, then served as executive chairman through March 2026. It also says he was appointed to the National Infrastructure Advisory Council in August 2022.

In March 2026 Gov. Kevin Stitt appointed Armstrong to the Senate seat vacated by Markwayne Mullin, whose resignation the Senate records as March 23, 2026. Armstrong's service began on March 24, 2026. His Senate biography gives January 3, 2027, as the end of his term and says he is not running in November. He serves on the Health, Education, Labor, and Pensions Committee and the Committee on Indian Affairs.