She was the only child of actress Dorothy Dickson and matinée idol Carl Constantine Hyson. Her mother was known for being the Toast of Broadway. Hyson made her acting debut at age three, playing her mother's daughter in a silent film shot by director George Fitzmaurice shot at New York's Paramount studios. Hyson moved to England with her parents who eventually divorced. Her mother had a successful run in Jerome Kern's musical Sally and became the highest-paid actress in London. Hyson was schooled in England and France, but "Little Dot", as she was nicknamed, made several West End appearances in children's roles including J.M. Barrie's Quality Street. After seeing her, aged 13, in the theatrical adaptation of Daisy Ashford's The Young Visiters, Sybil Thorndike told her mother, "She's going to be a star."
Career
After finishing school in Paris, Hyson appeared in Soldiers of the King with Cicely Courtneidge at age 19. Her professional theatrical debut was in Ivor Novello's play Flies in the Sun. She worked on films during the daytime and appeared on stage at night. Filming at Blackpool with Gracie Fields Sing As We Go and acting inthe West End in Dodie Smiths Touch Wood led to a nervous breakdown. She continued to be in light West End comedies and had a big hit in an adaptation of Jane Austen's Pride and Prejudice in 1936. In 1938 she appeared as Titania in Tyrone Guthrie's Old Vic revival of A Midsummer Night's Dream. During the Second World War, Hyson made several more films including You Will Remember with Robert Morley and the musical comedySpare a Copper with George Formby. She also acted in revue, musical comedy and plays like the thriller Pink String and Sealing Wax in 1943 and an adaptation from Trollope Scandal at Barchester in 1944. In 1945 she played Lady Windermere in Oscar Wilde's Lady Windermere's Fan. She worked at the secret codebreaking establishment Bletchley Park during World War II, and, although married to Robert Douglas, was visited there by Anthony Quayle, who became her second husband. Quayle recalled that: "She had gone to work as a cryptographer at Bletchley Park. I went to see her there and found her ill and exhausted with the long night shifts." She was a "byword for theatrical West End glamour" and after the war returned to the West End, joining John Gielgud’s Haymarket Company in 1945.
She was married twice—to actor Robert Douglas and then actor and director Sir Anthony Quayle. After marrying Quayle in 1947 she soon retired from the stage to concentrate on bringing up their three children.
Death
She was widowed in 1989 and died from a stroke on May 23, 1996, aged 81, in England, a year after the death of her mother, who died at age 102. It is not known whether she or her mother ever relinquished their United States citizenship and/or became British subjects.