 Garson was educated at King's College, London and the University of Grenoble, where she earned degrees in French and 18th-century literature.While aspiring to be an actress, she worked at an advertising agency as a company secretary along with George Sanders, who wrote in his autobiography that it was Garson who suggested he take up a career in acting.Garson's early professional appearances were on stage, starting at Birmingham Repertory Theatre in January 1932, when she was 27 years old.