Oklahoma Gov. Stitt Appoints Armstrong to Senate Vacancy

Oklahoma Governor Kevin Stitt appointed energy executive Alan Armstrong to the U.S. Senate on Tuesday, filling the vacancy left by Senator Markwayne Mullin following his confirmation as secretary of Homeland Security. The announcement, made during a morning press conference at the state capitol in Oklahoma City, came one day after the Senate approved Mullin's nomination in a 54-45 vote. Armstrong, a longtime leader in the natural gas industry, was sworn in later that afternoon by Senate President Pro Tempore Chuck Grassley, ensuring Oklahoma's continued full representation in Congress.

Stitt, a Republican, selected Armstrong for his extensive experience in energy infrastructure and his potential to address federal permitting challenges. Armstrong, 63, served as president and CEO of Williams Companies, a Tulsa-based natural gas pipeline operator, for 14 years before becoming executive chairman in 2025. He joined the company in 1986 as an engineer and has spent nearly four decades advancing its operations, which employ about 5,800 people nationwide. A third-generation Oklahoman raised near Bartlesville, Armstrong resigned from his board position to accept the Senate role.