She was best known for the films Genevieve (1953) and The Railway Children (1970), the long-running BBC comedy series Don't Wait Up (1983–1990), and for her distinguished theatre career in London's West End.

She changed her name to Dinah Sheridan, which she selected from a phone book, to play Wendy, at the age of 14, in a long-running theatrical production of Peter Pan starring Jean Forbes-Robertson.

[5] Stage appearances included Terence Rattigan's French Without Tears (1939, Oxford), J B Priestley's When We Are Married (1940, with Cyril Cusack, Llandudno) and The Golden Grain (1952, with Betty Balfour, Embassy Theatre, London).

Dinah's acting credits included appearing with Robert Helpmann in The Maker of Dreams (1937); and in Gallows Glorious, the first-ever three-act play on television (1938).

She postponed her film career to serve for two years as an ambulance driver at the start of World War II[7] at Welwyn Garden City, where she participated in repertory theatre.

[7] Notable films in the 1940s were Salute John Citizen (1942), Get Cracking (1943, with George Formby), Murder in Reverse (1945, with Chili Bouchier), For You Alone (1945), and the lead roles in The Hills of Donegal (1948) and The Story of Shirley Yorke (1949).

Sheridan then starred opposite Dirk Bogarde in Appointment in London (1952) and had a featured role as Grace Marston in The Story of Gilbert and Sullivan which was made as part of the Coronation celebrations of 1953.

[5] She made only one more cinema film after The Railway Children: The Mirror Crack'd (1980), which starred Elizabeth Taylor and Rock Hudson, with Angela Lansbury as Miss Marple.

After their 1965 divorce (which was granted to Sheridan on the grounds of cruelty), she resumed her career appearing in Margaret Williams' comedy Let's All Go Down the Strand (1967, alongside Gladys Cooper and Evelyn Laye, Phoenix Theatre, London).

She co-starred with long-standing friend and colleague Tony Britton and Nigel Havers in British sitcom, Don't Wait Up (1983–1990, BBC TV)[7] which had audiences of over 15 million.

[7] She made a memorable guest appearance as Dotty Mayhew in BBC TV's Lovejoy special The Prague Sun (1992), which also featured Donald Pleasence and Peter Vaughan.

[5] When Sheridan was the subject of the British TV show This Is Your Life in 1979, guests in the studio included John Gielgud, Evelyn Laye, Douglas Fairbanks Jr., Betty Marsden and Charles Hawtrey, and filmed tributes from Dirk Bogarde and Tony Britton.