Diane Grayson (born Diane Guinibert in 1948 in London, England) is an English actress.

When she was 14, Grayson played Louisa in the musical The Sound of Music for 18 months at the Palace Theatre in London. She later played "Jenny" in The Prime of Miss Jean Brodie (1969) and "Janie Harker" in Emmerdale. Her earliest television role was as "Penny Richardson" (niece of motel owner "Meg Richardson", played by Noele Gordon) in the early years of Crossroads. She also played Sandy Rexton in See No Evil (1971). She married Derek Ryan in 1973 took a career break to have children Amy born 1978 and Christopher in 1984 then started to teach drama at Act One Beginners in East Grinstead and to write a musical.