[1] As a young actress, Dunning was a member of an amateur theatre company in Altrincham.

In 1934, she took over a part from Wendy Hiller in Love on the Dole, at the Garrick Theatre in London.

[2] Other stage appearances for Dunning included Val Gielgud's Punch and Judy (1937),[3] A.

[10] Other screen roles played by Dunning included Leonie in Intimate Relations (1953), Auntie B. in Urge to Kill (1960), Mrs. Mitchell in Hoffman (1970), Betty Atherton in The Sextet (1972), Agnes Henderson in The House in Nightmare Park (1973), Miss Minchin in A Little Princess (1973), Mildred Finch in An Unofficial Rose (1974–1975), Lesley Whittle's mother in The Black Panther (1977), and Mrs. Crabtree in Children of the Stones (1977).

The Ruth Dunning and Jack Allen Collection at the University of Bristol holds some of her papers, including contracts, scripts, and photographs.