Kristi Lynn Arnold Noem (née Arnold; born November 30, 1971) is an American politician serving since 2025 as the 8th United States secretary of homeland security. A member of the Republican Party, she served from 2019 to 2025 as the 33rd governor of South Dakota and from 2011 to 2019 represented South Dakota's at-large congressional district in the U.S. House of Representatives.