Jane Wymark is an English actress. She is the daughter of English actor Patrick Wymark (1926–1970) and American writer and playwright Olwen Wymark (1932–2013). She is best known for her role as Morwenna Chynoweth Whitworth (Morwenna Carne by the end of the series) in the 1970s BBC television drama Poldark (1977), and more recently for her role as Joyce Barnaby (1997–2011) in the ITV detective series Midsomer Murders.

She has appeared in television dramas such as "The Bass Player and the Blonde," "A Touch of Frost," "Dangerfield," "Lovejoy," and "The Crane in the Sky." She also appeared as Jill Mason in the Birmingham Rep production of "Equus." She is the great-granddaughter of novelist and short story writer W. W. Jacobs.