Mason began his career as a stage actor on the West End, before transitioning into leading man roles in films during the early 1940s.

Moving to the United States in the following decade, Mason starred in such films as George Cukor's A Star Is Born (1954) - earning a Golden Globe for Best Actor in a Motion Picture – Musical or Comedy, Alfred Hitchcock's North by Northwest (1959), Stanley Kubrick's Lolita (1962), Warren Beatty's Heaven Can Wait (1978) and Sidney Lumet's The Verdict (1982).

He also starred in a number of successful British and American films from the 1950s to the early 1980s, including: The Desert Fox (1951), Julius Caesar (1953), Bigger Than Life (1956), 20,000 Leagues Under the Sea (1954), Journey to the Center of the Earth (1959), Georgy Girl (1966), Spring and Port Wine (1970), and The Boys from Brazil (1978).

Following his death in 1984, his ashes were interred near the tomb of his close friend, fellow English actor Sir Charlie Chaplin.

Mabel—who was "uncommonly well-educated" and had lived in London to study and begin work as an artist before returning to Yorkshire to care for her father—was "attentive and loving" in raising her sons.

Mason was educated at Marlborough College and took a first in architecture at Peterhouse, Cambridge, where he became involved in stock theatre companies in his spare time.

[7] In 1933, Alexander Korda gave Mason a small role in The Private Life of Don Juan but sacked him three days into shooting.

He established himself as a leading man in Britain in a series of films: The Patient Vanishes (1941); Hatter's Castle (1941) with Robert Newton and Deborah Kerr; The Night Has Eyes (1941); Alibi (1942) with Margaret Lockwood; Secret Mission (1942); Thunder Rock (1942) with Michael Redgrave; and The Bells Go Down (1943) with Tommy Trinder.

Mason became hugely popular for his brooding anti-heroes, and occasional outright villains, in the Gainsborough series of melodramas of the 1940s, starting with The Man in Grey (1943).

The film was a huge hit and made him and co-stars Lockwood, Stewart Granger and Phyllis Calvert top-level stars.

[11] Mason starred in two wartime dramas, They Met in the Dark (1943) and Candlelight in Algeria (1944), then returned to Gainsborough melodrama with Fanny By Gaslight (1944) with Granger and Calvert; it was another big hit.

[12][13] Sydney Box cast Mason in a psychodrama about musicians, The Seventh Veil (1945), as the tyrannical guardian of pianist Ann Todd.

He then received his best reviews to date playing a mortally wounded IRA bank robber on the run in Carol Reed's Odd Man Out (1947).

Mason went to Hollywood for his first film, Caught (1949), directed by Max Ophüls, then played Gustave Flaubert in MGM's Madame Bovary (1949).

At Fox, he reprised his role as Rommel in The Desert Rats (1953), then he was reunited with Mankiewicz at MGM, playing Brutus in Julius Caesar (1953), opposite Marlon Brando.

Warner Bros., hired him to play Judy Garland's leading man in the George Cukor directed musical drama film A Star Is Born (1954).

Jack Moffitt of The Hollywood Reporter praised the film writing, "A Star Is Born is the perfect blend of drama and musical — of cinematic art and popular entertainment.

[21] Mason appeared with Lucille Ball and Desi Arnaz in Forever, Darling (1956) then starred in and produced a film at Fox, Bigger Than Life (1956), directed by Nicholas Ray.

(1958) and The Decks Ran Red (1958) then played a suave master spy hunting down Cary Grant with romantic assistance from Eva Marie Saint in North by Northwest (1959), directed by Alfred Hitchcock.

At Fox he had a huge hit returning to Jules Verne science fantasy as the determined Scottish scientist and explorer in Journey to the Centre of the Earth (1959), taking over a role meant for Clifton Webb.

He provided a supporting role in Duffy (1968), The Blue Max (1966) and Mayerling (1968) but was top billed in The Sea Gull (1968) for Sidney Lumet and starred as Bradley Morahan in Age of Consent (1969) for Michael Powell, a film which Mason also produced.

Mason supported Charles Bronson in Cold Sweat (1970) and Lee Van Cleef in Bad Man's River (1971).

He had support roles in The MacKintosh Man (1973), 11 Harrowhouse (1974), The Marseille Contract (1974), and Great Expectations (1974) and was top billed in Mandingo (1975).

Mason's later 70s performances included Kidnap Syndicate (1975), The Left Hand of the Law (1975), Autobiography of a Princess (1975), Inside Out (1975), The Flower in His Mouth (1975), Voyage of the Damned (1976), Hot Stuff (1977), Cross of Iron (1977), Jesus of Nazareth (1977), The Yin and the Yang of Mr. Go (1978), The Water Babies (1978), Heaven Can Wait (1978), The Boys from Brazil (1978), Murder by Decree (1979) (as Dr. Watson), The Passage (1979), Bloodline (1979) and as the vampire's servant, Richard Straker, in Salem's Lot (1979).

Mason was in North Sea Hijack (1980), supporting Roger Moore, Evil Under the Sun (1982), Ivanhoe (1982), and A Dangerous Summer (1982).

[35] Clarissa Kaye Mason left her holdings to the religious guru Sathya Sai Baba, including the actor's ashes, which she had retained in their shared home.