Dirk Arthur Kempthorne (born October 29, 1951 in San Diego, California), was the U.S. Secretary of the Interior, who served under President George W. Bush from 2006–2009. A Republican, Kempthorne previously served as Governor and as a U.S. Senator from Idaho. He is reportedly exploring a bid for the Republican Presidential nomination in 2012.

Kempthorne was first elected to public office as mayor of Boise in 1985, where he served for seven years. According to The New York Times, over the course of his career in public service, Kempthorne established a reputation as "a personable leader with a strong understanding of issues."

Kempthorne is notable for his conservative views, particularly on economic issues.