Oil and gas executive Alan Armstrong has officially been sworn in as the newest Republican U.S. Senator from Oklahoma, replacing former Sen. Markwayne Mullin, who was just elevated to lead the Department of Homeland Security.
Armstrong, a longtime energy industry heavyweight and former CEO of Williams Companies, took the oath of office Tuesday in Washington, just hours after Oklahoma Republican Gov. Kevin Stitt announced his appointment.
“I am honored to announce my appointment of Alan Armstrong to the U.S. Senate.
Alan is a proud third-generation Oklahoman, staunch conservative, respected business leader, and a devoted family man with an inspiring American Dream story.
He is entering the U.S. Senate at a critical time for advancing reforms to secure America’s energy future. I have no doubt that his perspective will be influential in moving the needle on permitting reform to unlock American competitiveness and energy affordability for generations to come.
Congratulations, Alan! You’ll make Oklahoma proud!”
I am honored to announce my appointment of Alan Armstrong to the U.S. Senate.
Alan is a proud third-generation Oklahoman, staunch conservative, respected business leader, and a devoted family man with an inspiring American Dream story.
He is entering the U.S. Senate at a… pic.twitter.com/CH8y2O7DcJ
— Governor Kevin Stitt (@GovStitt) March 24, 2026
Watch Armstrong’s speech after he was appointed by the Governor. Stitt:
On Sunday, The Gateway Pundit reported that Oklahoma Governor Kevin Stitt has chosen oil and gas executive Alan Armstrong to fill the U.S. Senate seat being vacated by Sen. Markwayne Mullin.
The move comes after Mullin was confirmed and sworn in as DHS Secretary, a transition that instantly triggered a high-stakes appointment battle in deep-red Oklahoma.
Armstrong’s appointment keeps the Senate seat firmly in Republican hands, preserving the GOP majority. However, under Oklahoma law, there’s a catch:
- Armstrong must serve only as a temporary replacement
- He cannot run for the seat in the 2026 election after signing a required pledge
That means his tenure is expected to last until early 2027 or until voters elect a permanent successor later this year.
WATCH:
JUST IN: Markwayne Mullin’s replacement to the US Senate out of Oklahoma has been SWORN IN to office
Alan Armstrong is the newest Republican Senator from Oklahoma
Hopefully he will be a 100% RELIABLE MAGA vote for policies like the SAVE America Act
pic.twitter.com/rYeZZ5WY45
— Eric Daugherty (@EricLDaugh) March 24, 2026
However, reports reveal Armstrong previously donated $5,800 to former Rep. Adam Kinzinger, one of the most vocal anti-Trump Republicans.
The post Oil and Gas Executive Alan Armstrong SWORN IN as New GOP Senator to Replace Markwayne Mullin appeared first on The Gateway Pundit.

JUST IN: Markwayne Mullin’s replacement to the US Senate out of Oklahoma has been SWORN IN to office