Film Noir is a genre of crime film that was popularized from the 1930s to the 1950s. Its cynical characters, stark lighting, and existential philosophy are hallmarks of the style. The tropes often came about from the rise of "hard-boiled" crime fiction from the Great Depression, with the familiar tropes of urbanism, fast-paced slang, sex, and violence came into print, which contrasts the previous decade's country house mystery . Its visual identity relies heavily on things like sharp contrasts and dramatic compositions influenced by German Expressionism .

Film Noir developed from a combination of international artistic movements and domestic economic circumstances. German Expressionist filmmakers who fled Europe during the prewar period brought new lighting techniques, visual distortion, and psychological storytelling to Hollywood. At the same time, the economic effects of the Great Depression shaped a generation of stories about morality, desperation, and survival in modern cities.

The style gained definition during the 1940s, when wartime uncertainty and postwar disillusionment pushed Hollywood toward darker narratives. Classic Noir films explored themes such as betrayal, obsession, organized crime, and the consequences of desire. Hardboiled detective fiction by authors like Raymond Chandler and Dashiell Hammett also influenced the tone and subject matter.

By the mid 1950s, the traditional cycle of Film Noir began to decline as color cinematography and new genres gained prominence.

Film Noir relies on low key lighting, deep shadows, and strong contrasts between light and dark. Scenes often take place in dim alleyways, smoky nightclubs, rain soaked streets, and sparsely lit apartments. Venetian blind shadows, silhouette compositions, and backlit figures create a sense of secrecy and surveillance. Fog, cigarette smoke, and neon reflections enhance the feeling of urban claustrophobia.

Costuming includes dark suits, trench coats, tailored dresses, fedoras, silk gloves, and fur trimmed outerwear. Characters often appear polished yet worn, attractive yet troubled. Props such as cigarettes, rotary telephones, desk lamps, detective files, and glasses of liquor further reinforce the tone.

The music typically associated with film noir is 1940s-1950s jazz, often at a slow tempo, with a strong saxophone presence, and a feeling of melancholy and sensuality.

For more, see the TVTropes index on the genre, as well as a list of one-off episodes in non-noir media.