Dirk Arthur Kempthorne (born October 29, 1951) is an American Republican politician from Idaho, who currently is the governor of that state.

Kempthorne's first major political victory was in 1986 when he became the mayor of the city of Boise. He served in that position until 1993, when he became a member of the United States Senate for Idaho. He had been elected in 1992 to replace another Republican, Steven Symms, who was retiring. Kempthorne served one term, not running for reelection in 1998, deciding instead to run for Governor of Idaho, winning the Republican nomination as a supporter of the retiring Republican governor, Phil Batt.

Kempthorne won the election in a landslide, receiving 68% of the vote while his Democratic opponent, Robert Huntley , received 29%. He was reelected in 2002 with 56% of the vote, compared to his Democratic opponent, Jerry Brady , who polled 42%. Kempthorne is notable for his conservative views, particularly on economic issues.

|- style="text-align: center;" | width="30%" |Preceded by:
Steve Symms | width="40%" style="text-align: center;" |United States Senate - Idaho
1993–1999 | width="30%" |Succeeded by:
Mike Crapo

|- style="text-align: center;" | width="30%" |Preceded by:
Phil Batt | width="40%" style="text-align: center;" |Governor of Idaho
1999– | width="30%" |Succeeded by:
Incumbent