Donal "Donald" O'Brien (September 15, 1930) is a French-born Irish film and television actor. In his near 40-year career, O'Brien appeared in dozens of stage performances and in more than 60 film and television productions. O'Brien was born in Pau, Pyrénées-Atlantiques, raised in both Northern France and Dublin, Ireland with his family, and made his feature film debut in 1953 with Anatole Litvak's war drama Act of Love. He studied acting in Dublin and initially joined the Gate Theatre at age 19 before making the transition to film several years later. O'Brien's performance in The Train (1964), in which he played an SSFeldwebel, led to his first breakout role in Grand Prix (1966) starring alongside James Garner and Eva Marie Saint.

1966