Jean Lyndsey Torren Marsh (1 July 1934 – 13 April 2025) was an English actress and writer. She co-created and starred in the ITV series Upstairs, Downstairs (1971–1975), for which she won the 1975 Emmy Award for Outstanding Lead Actress in a Drama Series for her performance as Rose Buck. She reprised the role in the BBC's revival of the series (2010–2012).

Marsh co-created the television series The House of Eliott in 1991. Her film appearances include Cleopatra (1963), Frenzy (1972), The Eagle Has Landed (1976), The Changeling (1980), Return to Oz (1985), Willow (1988), Fatherland (1994) and Monarch (2000). She is also known for three roles in Doctor Who: as Joan of England in The Crusade; Sara Kingdom, a companion of the First Doctor; and a villain opposite the Seventh Doctor. She was briefly married to Jon Pertwee, who played the Third Doctor in the series, from 1955 to 1960.