Mabel Gwynedd Terry-Lewis (born as Mabel Gwynedd Lewis) ( 28 October 1872 – 28 November 1957) was an English actress and a member of the Terry-Gielgud dynasty of actors of the 19th and 20th centuries.
After a successful career in her twenties and thirties she married and retired from the stage in 1904. Her husband died in 1917 and she returned to the theatre in 1920, continuing to act on stage and in films until the late 1940s. Among her celebrated roles was Lady Bracknell in The Importance of Being Earnest, which she played opposite her nephew John Gielgud in 1930.