Cul-de-sac is a 1966 British black comedy psychological thriller film directed by Roman Polanski, written by Polanski and Gérard Brach, and starring Donald Pleasence, Françoise Dorléac, Lionel Stander and Jack MacGowran, with Iain Quarrier, Geoffrey Sumner, Renée Houston, William Franklyn, Marie Kean and Trevor Delaney in supporting roles.

Polanski's second English-language feature, it follows two injured gangsters who take refuge in the remote island castle of a young British couple in the North of England, spurring a series of mind games and violent altercations.

Gruff American gangster Dickey pushes his broken-down car along a causeway through rising seawater while his eccentric companion Albie lies inside, bleeding from a gunshot wound after a botched robbery.

Cut off by the unexpected rising tide, they are on the only road to the remote tidal island of Lindisfarne in Northumberland, where, in a dark castle on a hilltop, a deeply neurotic and effeminate middle-aged Englishman named George lives with his French second wife, the young and promiscuous Teresa.

As day breaks, he sits down on a rock in a fetal position and weeps hysterically, shouting out the name of his first wife, as the early morning tide rises around him.

Christopher Weedman also notes the film's similarities with "such hard-edged Humphrey Bogart hostage thrillers as The Petrified Forest (Archie Mayo, 1936), Key Largo (John Huston, 1948), and The Desperate Hours (William Wyler, 1955).

Lindisfarne Castle, which served as the home in the film, is now a National Trust property and can be toured by the public; despite the passage of time, the building and its surroundings are largely unchanged.