Tom Courtenay (pronounced "Courtney") (born February 25, 1937) is a British actor who came to prominence in the early 1960s with a succession of critically-acclaimed films including The Loneliness of the Long-distance Runner (1962), Billy Liar (1963) and Dr. Zhivago (1965). (In the latter two, he appeared alongside Julie Christie).

He was born Thomas Courtenay in Hull, England, and made his stage début in 1960 with the Old Vic company. His Hamlet at the Edinburgh Festival of 1968 marked him out as one of Britain's leading stage actors as well as a film actor. He showed his comic talent again by creating the role of Norman in Alan Ayckbourn's trilogy, The Norman Conquests . He was briefly married to the actress, Cheryl Kennedy. His television appearances have been relatively few, but have included She Stoops to Conquer on BBC and several Ayckbourn plays. He appeared in "I Heard the Owl Call My Name" on US television in 1973.

His best known film role after the 1960s is probably in The Dresser, (from Ronald Harwood's play of the same name, in which he also appeared), with Albert Finney. In 2003 he appeared on the West End stage again in the one-man show Pretending To Be Me, as Philip Larkin.

Sir Thomas Courtenay was knighted in 2001.