English actress. Born May 22, 1914, in London, England; dau. of Sir Lewis Casson (actor and director) and Dame Sybil Thorndike (1882–1976, actress); sister of Christopher Casson (1912–1996, actor), John Casson (1909–1999, actor and producer) and Ann Casson (1915–1990, actress); m. William Devlin.

Made stage debut at the Lyric as Belinda Cratchitt in A Christmas Carol (1921); other plays include The Admirable Crichton, Quality Street, Peter Pan, Mariners, Jane Clegg, Becket, Strange Orchestra, Mrs. Siddons, The Convict, Rosetti and The Master of Thornfield, as Jane Eyre.