G. Kim Wincup was educated at DePauw University, receiving a B.A. in Political Science in 1966. He then attended the University of Illinois College of Law, receiving a J.D. in 1969. After law school, Wincup served as a judge advocate in the United States Air Force Judge Advocate General's Corps from 1970 to 1973. In 1974, he became counsel to the United States House Committee on Armed Services. He would serve there for fifteen years, eventually becoming the committee's assistant general counsel. Wincup left government service in 1994, becoming senior vice president of SAIC.