Mike Mazzei won the Oklahoma Republican gubernatorial primary runoff on Tuesday, securing the GOP nomination for governor with the support of former President Donald Trump. Mazzei defeated incumbent Attorney General Gentner Drummond to claim the Republican nomination ahead of the November general election.

Trump's endorsement of Mazzei was widely seen as a significant factor in the race, continuing a pattern of the former president actively shaping Republican primary outcomes across the country heading into the 2026 midterm cycle. Oklahoma is a reliably Republican state, making the GOP nomination effectively decisive in the gubernatorial contest.

The primary runoff was necessary after neither candidate secured a majority of votes in the initial June Republican primary. Mazzei, a former state senator and financial advisor, positioned himself as a close ally of Trump throughout the campaign, while Drummond had faced criticism from Trump-aligned circles over his tenure as attorney general.

With his runoff victory, Mazzei cleared a key hurdle in one of the most watched Republican gubernatorial contests of the 2026 cycle. He will face the Democratic nominee in November in a state that has voted Republican in every presidential election since 2004.