The Man in Half Moon Street is a 1945 American melodrama horror romance science-fiction film about a man who retains his youth and cannot die, living throughout the ages. The plot is similar to that of Oscar Wilde's Picture of Dorian Gray and its 1945 film adaptation, although the source of the main character's eternal youth is medical and not supernatural. The film is based on a 1939 West End play of the same title by Barré Lyndon and stars Nils Asther and Helen Walker with direction by Ralph Murphy.