James Neville Mason (; 15 May 1909 – 27 July 1984) was an English actor. He achieved considerable success in British cinema before becoming a star in Hollywood. He was nominated for three Academy Awards, three Golden Globes (winning once) and two BAFTA Awards throughout his career.

Mason began his career as a stage actor on the West End, before transitioning into leading man roles in films during the early 1940s. He was the top box-office attraction in the UK in 1944 and 1945; his British films included The Seventh Veil (1945) and The Wicked Lady (1945). He starred in Odd Man Out (1947), the first recipient of the BAFTA Award for Best British Film.

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), 20,000 Leagues Under the Sea (1954), Bigger Than Life (1956), 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.