Film noir is a cinematic term used primarily to describe stylish Hollywood crime dramas, particularly those that emphasize cynical attitudes and sexual motivations. Hollywood's classic film noir period is generally regarded as extending from the early 1940s to the late 1950s. Film noir of this era is associated with a low-key black-and-white visual style that has roots in German Expressionist cinematography. Many of the prototypical stories and much of the attitude of classic noir derive from the hardboiled school of crime fiction that emerged in the United States during the Depression.

The term film noir, French for "black film", first applied to Hollywood films by French critic Nino Frank in 1946, was unknown to most American film industry professionals of the classic era. Cinema historians and critics defined the noir canon in retrospect. Before the notion was widely adopted in the 1970s, many of the classic film noirs were referred to as melodramas. The question of whether film noir qualifies as a distinct genre is a matter of ongoing debate among scholars.