Michael Vincent Forrestal (November 26, 1927 – January 11, 1989) was one of the leading aides to McGeorge Bundy, the National Security Advisor of President John F. Kennedy. He was seen as a pivotal figure in the changing of U.S. foreign policy, including recommending support for the coup d'état that deposed the first president of South Vietnam, Ngô Đình Diệm.