Diane Lavinia Hart (20 July 1926 – 7 February 2002) was an English actress in both films and West End theatre, political campaigner, and inventor.

In this political light comedy, centred round an 'Earl of Lister' and a local by-election, Hart played the comic role of the young housemaid Bessie opposite A. E. Matthews.

She also enjoyed a six-month stint as Mollie Ralston in one of the earliest runs of The Mousetrap (Ambassadors Theatre (1953), and then abandoned the stage for 11 years in favour of television and the cinema.

In March 1963, she translated the Sardou play Divorce A La Carte and appeared in the production of the same with John Justin, Barry Shawzin and Katy Greenwood at the Phoenix Theatre in London.

She had another long vaudeville residency acting with Terence Alexander and replacing Moira Lister in the successful Ray Cooney/John Chapman farce Move Over, Mrs Markham (1972).

She then took a role in Morality (Royal Court Theatre Upstairs, 1971), a piece by Jeremy Seabrook and Michael O'Neill, directed by William Gaskill, a domestic drama about a schoolboy involved in a homosexual relationship with a teacher.

Hart's film career started much earlier, in the 1940s, with a small role as a bridesmaid in the Margaret Lockwood costume drama The Wicked Lady (1945), and included a contract to 20th Century-Fox.

Hart also worked for Jean Negulesco in Britannia Mews (1949), scripted by Ring Lardner Jr., and playing opposite David Niven in the musical Happy Go Lovely (1951).

She was awarded £750 damages at the High Court[4] to compensate her for the noise and nuisance caused by the construction of the Ismaili Centre opposite her home in London nearby the Victoria and Albert Museum.

Hart was also plaintiff in person in her litigation in 1985, when she was awarded £15,000[5] in libel damages after a clip was taken from Games That Lovers Play (1971), a film in which she appeared with Joanna Lumley, Richard Wattis, Jeremy Lloyd, Penny Brahms and Nan Munro.