John Gavin (born John Anthony Golenor; April 8, 1931) is an American film actor and a former United States Ambassador to Mexico from 1981–86 and head of the Screen Actors Guild from 1971-73. He is 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, and for being cast as James Bond in Diamonds Are Forever (1971) before Sean Connery agreed to reprise the role.