Sir Thomas Daniel Courtenay (; born 25 February 1937) is an English actor who came to prominence in the early 1960s with a succession of films, including The Loneliness of the Long Distance Runner (1962), Billy Liar (1963), and Doctor Zhivago (1965). Since the mid-1960s, he has been known primarily for his work in the theatre, although he received an Academy Award nomination for Best Actor for the film adaptation of The Dresser (1983), which he had performed on the West End and on Broadway. He received a knighthood in February 2001 for his service to cinema and theatre.