Donald Calthrop (11 April 1888 – 15 July 1940) was a British stage and film actor who became one of the most recognisable figures in British cinema of the 1920s and 1930s. Specialising in eccentric, nervous, or sinister character roles, his career was closely linked to director Alfred Hitchcock, for whom he played memorable roles. These include his role as the blackmailer Tracy in *Blackmail* (1929), Britain's first sound film, and his appearances in *Murder!* (1930) and *Sabotage* (1936). Outside of his collaborations with Hitchcock, he delivered notable performances in films such as *Rome Express* (1932) and demonstrated his versatility as Bob Cratchit in *Scrooge* (1935). Although he never received any formal awards, he is recognised by critics as a character actor essential to British cinema's transition to sound, valued for his ability to instil a subtle unease and considerable psychological depth into his characters. His untimely death cut short a prolific and highly influential career.