The Twentieth Duke (Italian: Il ventesimo duca) is a 1945 Italian comedy film directed by Lucio De Caro and starring Paola Veneroni, Roberto Villa and Paola Borboni.The film is based on a 1925 play by Ugo Falena which had previous been made into films on two occasions The Last Lord (1926) and The Woman Dressed As a Man (1932). The story tells of the only surviving relative of an old Duke, his granddaughter, who pretends to be a man in order to convince him that the line of succession is secure.

It was shot at the Cinecitta Studios in Rome. It was made in 1943, but its release was delayed for two years. It did not go on a full national release until early 1946.