Twentieth Century is a 1934 American pre-Code screwball comedy film directed by Howard Hawks and starring John Barrymore, Carole Lombard, Walter Connolly, and Roscoe Karns. Much of the film is set on the 20th Century Limited train as it travels from Chicago to New York City. Ben Hecht and Charles MacArthur adapted their 1932 Broadway play of the same name—itself based on the unproduced play Napoleon of Broadway by Charles Bruce Millholland—with uncredited contributions from Gene Fowler and Preston Sturges.

Along with Frank Capra's It Happened One Night, also released in 1934 (which coincidentally has the same music over the opening titles), Twentieth Century is considered to be a prototype for the screwball comedy. "Howard Hawks' rapid-fire romantic comedy established the essential ingredients of the screwball – a dizzy dame, a charming, but befuddled, hero, dazzling dialogue, and a dash of slapstick." Its success propelled Lombard into the front ranks of film comediennes. The film was added to the National Film Registry of the Library of Congress in 2011.