Porridge is a 1979 British comedy film directed by Dick Clement and starring Ronnie Barker, Richard Beckinsale, Fulton Mackay and Brian Wilde. It was written by Clement and Ian La Frenais based on their BBC television series Porridge (1974–1977). Most of prison officers and inmates from the original series appear in the film, with the notable exceptions of Lukewarm, Blanco, Heslop and Harris. There is also a different governor, played by Geoffrey Bayldon rather than series regular Michael Barrington.

William Fulton Beith Mackay was a Scottish actor and playwright, best known for his role as prison officer Mr. Mackay in the 1970s television sitcom Porridge.