Un Chien Andalou (French pronunciation: [œ̃ ʃjɛ̃ ɑ̃dalu], An Andalusian Dog) is a 1929 French silent short film directed, produced and edited by Luis Buñuel, who also co-wrote the screenplay with Salvador Dalí. Buñuel's first film, it was initially released in a limited capacity at Studio des Ursulines in Paris, but became popular and ran for eight months.

Un Chien Andalou has no plot in the conventional sense of the word. With disjointed chronology, jumping from the initial "once upon a time" to "eight years later" without events or characters changing, it uses dream logic in narrative flow that can be described in terms of the then-popular Freudian free association, presenting a series of tenuously related scenes. Un Chien Andalou is a seminal work of surrealist cinema.

The film is set to enter the public domain in the United States on January 1, 2025.