After studying at the Royal Academy of Dramatic Art, he achieved prominence in the 1960s as part of actors of the British New Wave.

His later roles include Last Orders (2001), Nicholas Nickleby (2002), Quartet (2012), 45 Years (2015), and The Guernsey Literary and Potato Peel Pie Society (2018).

He attended Kingston High School and went on to study English at University College London, where he failed his degree.

This was followed by The Loneliness of the Long Distance Runner, directed by Tony Richardson, and Billy Liar, two highly acclaimed films and performances which helped usher in the British New Wave of the early-to-mid-1960s.

In 1969 and 1971, he was in two spy-comedies, Otley (in the title role) along with Catch Me A Spy (1970) starring Kirk Douglas; and previously, in 1968, he co-starred in a serious film of that genre, A Dandy in Aspic (1968), opposite Laurence Harvey.

Courtenay's working relationship with Wrede returned to film when he played the title role in the latter's 1970 production of One Day in the Life of Ivan Denisovich.

[6] His first roles for the Royal Exchange were as Faulkland in Richard Brinsley Sheridan's The Rivals and the hero of Heinrich von Kleist's The Prince of Homburg.

Courtenay originated the role of Norman in Ronald Harwood's The Dresser which was first produced in the West End in 1980.

He then was cast as Norman in the film adaptation of The Dresser (1983), acting opposite Albert Finney as Sir with performances from Eileen Atkins, Edward Fox, and Michael Gough.

Famed critic from the Chicago Sun-Times, Roger Ebert praised Courtenay for his performance writing, "He is perfect for playing proud, resentful, self-doubting outsiders.

"[7] Both Courtenay and Finney received nominations for Best Actor in the 1983 Academy Awards for their roles, losing to Robert Duvall in Tender Mercies.

And for an actor known to be cast in good or great films, he surprisingly co-starred in what's been considered one of the worst movies ever, the infamous Leonard Part 6 starring Bill Cosby.

Rather unexpectedly, he had a cameo role as the anthropologist Bronisław Malinowski in the George Lucas 1995 US TV film Young Indiana Jones and the Treasure of the Peacock's Eye.

Harry said he knew the guest had set off some time ago, which was followed by a cut to the 1962 film The Loneliness of the Long Distance Runner in which Courtenay's character was running.

It comprises a selection of the letters exchanged between Courtenay and his mother, interspersed with his own recollections of life as a young student actor in London in the early 1960s.