Kyl was born on April 25, 1942 in Oakland, Nebraska. He was the son of John Henry Kyl, a Republican congressman from Iowa. In 1964 he graduated from the University of Arizona with a bachelor's degree in political science. In 1966 Kyle graduated Phi Beta Kappa from the University of Arizona's James E. Rogers College of Law. He was editor-in-chief of the school's law review. In 1966 Kyle joined the Phoenix, Arizona law firm of Jennings, Strouss, and Salmon. In 1985, he was a member of the Phoenix Chamber of Commerce. He is married to Caryll Collins. They have two children and several grandchildren.