She is the daughter of the actor, Mervyn Johns, and her roots are in west Wales, although she happened to be born in Pretoria, South Africa, while her parents were on tour there. Her mother Alys Steele was a concert pianist and her son Gareth Forwood is an actor.
She made her film debut in 1938, in the movie version of Winifred Holtby's novel, South Riding. In 1944 she appeared opposite her father in Halfway House, and in 1948 starred as a mermaid in Miranda. She successfully made the transition to Hollywood, appearing in The Court Jester (1956) as Danny Kaye's love interest. Another of her best known film roles was that of Mrs Banks in Mary Poppins.
She has also appeared on television and on stage, most memorably in Stephen Sondheim's musical, A Little Night Music. The song, Send in the Clowns, was written with her in mind, and in 1973 she won a Tony award for her role in the musical.
Glynis Johns is an accomplished dancer, and was actually qualified to teach ballet at the age of ten. She also is a trained pianist and singer. Able to undertake any role and with a career spanning seven decades, Glynis Johns is often cited as the "complete actress". She has been married four times, including a marriage to Anthony Forwood, father of her son Gareth and the former manager to Sir Dirk Bogarde. Glynis Johns is regarded as one of the most beautiful women of all time and has been the subject of countless magazine covers and pin-up posters throughout her career.