A Farewell to Arms is a novel by American writer Ernest Hemingway, set during the Italian campaign of World War I. First published in 1929, it is a first-person account of an American, Frederic Henry, serving as a lieutenant (Italian: tenente) in the ambulance corps of the Italian Army. The novel describes a love affair between the American expatriate and an English nurse, Catherine Barkley.

Its publication ensured Hemingway's place as a modern American writer of considerable stature. The book became his first best-seller and has been called "the premier American war novel from [...] World War I". The title might be taken from a 16th‑century poem of the same name by the English dramatist George Peele.

The novel has been adapted a number of times: initially for the stage in 1930; as a film in 1932, and again in 1957; and as a three-part television miniseries in 1966. The film In Love and War, made in 1996, depicts Hemingway's life in Italy as an ambulance driver in events prior to his writing of A Farewell to Arms.