Markwayne Mullin (born 1977) is a Cherokee Nation citizen who made history in March 2026 by becoming the ninth U.S. Secretary of Homeland Security, the first tribal member to serve in the Cabinet. Appointed by President Donald Trump after Kristi Noem was fired, Mullin's political career includes serving as a U.S. Representative for Oklahoma's 2nd district (2013–2023) and as a U.S. Senator (2023–2026), where he was the first tribal citizen in the Senate since 2005. Before politics, he took over his family's plumbing business in 1998, growing it into Oklahoma's largest, and he also had a brief professional MMA career with a 5-0 record. Mullin overcame a speech impediment and clubfoot in his youth, and he sold his businesses in 2021 before entering the Senate. He won his Senate seat in a 2022 special election against Democrat Kendra Horn, capping a remarkable rise from local entrepreneur to a key figure in national security.