Born in Council, Idaho, Craig was raised on a ranch in Washington County. He attended the University of Idaho, receiving a Bachelor of Arts degree in political science from the university in 1969, and later briefly attended George Washington University before returning to Washington County in 1971 to work in his family's ranching business. Following a brief stint in the Idaho Army National Guard, Craig ran for and won a seat in the Idaho Senate in 1974, and was re-elected in 1976 and 1978, before his successful first run for Congress to represent Idaho's 1st congressional district in the House of Representatives in 1980. He won reelection four times before running for the U.S. Senate in 1990, defeating Ron J. Twilegar in the general election and winning reelection in 1996 and 2002.