James Neville Mason (15 May 1909 – 27 July 1984) was a three-time Academy Award-nominated British actor who attained stardom in both British and American films.

Mason was born in Huddersfield, Yorkshire, to John and Mabel Mason; his father was a wealthy merchant. Mason had no formal training as an actor and initially embarked upon it for fun. He was educated at Marlborough College, and earned a first in architecture at Peterhouse, Cambridge where he became involved in stock theatre companies in his spare time. After Cambridge he joined the Old Vic theatre in London under the guidance of Tyrone Guthrie and Alexander Korda, who gave Mason a small film role in 1933 but fired him a few days into shooting.

From 1935 to 1948 he starred in many British quota quickies. A conscientious objector during World War II (something which caused his family to break with him for many years), he became immensely popular for his brooding anti-heroes in the Gainsborough series of melodramas of the 1940s, including The Man in Grey and The Wicked Lady. He also starred with Deborah Kerr and Robert Newton in 1942's Hatter's Castle. Mason starred in the critically acclaimed and immensely popular The Seventh Veil that set box office records in postwar Britain and catapulted him to international film stardom. In 1949, he made his first Hollywood film, Caught, and then went on to star in many more feature films and early TV shows. Nominated three times for an Oscar, he never won one.