Night Mail is a 1936 documentary film about a London, Midland and Scottish Railway (LMS) mail train from London to Scotland, produced by the GPO Film Unit. The film features lines (sometimes referred to as "film commentary" by W. H. Auden, written for existing footage. Benjamin Britten scored the film. The film was directed by Harry Watt and Basil Wright, and narrated by John Grierson and Stuart Legg. The Brazilian filmmaker Alberto Cavalcanti was sound director.