Thou Art the Man is a lost 1920 American silent drama film produced by Famous Players–Lasky and released through Paramount Pictures. Thomas N. Heffron directed the film which starred stage and matinee idol Robert Warwick and Lois Wilson. It is based on a novel, Myles Calthorpe, I.D.B. by F. E. Mills Young, with a screenplay by Margaret Turnbull.