John Gavin (April 8, 1931 – February 9, 2018) was an American actor who was the United States Ambassador to Mexico (1981–86) and the president of the Screen Actors Guild (1971–73). He was best known for his performances in the films Imitation of Life (1959), Spartacus (1960), Psycho (1960), and Thoroughly Modern Millie (1967), playing leading roles in a series of films for producer Ross Hunter.