Solaris (Russian: Солярис, tr. Solyaris) is a 1972 Soviet psychological science fiction film based on Stanisław Lem's 1961 novel of the same title. The film was co-written and directed by Andrei Tarkovsky, and stars Donatas Banionis and Natalya Bondarchuk. The electronic music score was performed by Eduard Artemyev and features a composition by J.S. Bach as its main theme. The plot centers on a space station orbiting the fictional planet Solaris, where a scientific mission has stalled because the skeleton crew of three scientists have fallen into emotional crises. Psychologist Kris Kelvin (Banionis) travels to the station to evaluate the situation, only to encounter the same mysterious phenomena as the others.

Solaris won the Grand Prix Spécial du Jury at the 1972 Cannes Film Festival and was nominated for the Palme d'Or. It received critical acclaim, and is often cited as one of the greatest science fiction films in the history of cinema. The film was Tarkovsky's attempt to bring greater emotional depth to science fiction films; he viewed most Western works in the genre, including 2001: A Space Odyssey (1968), as shallow due to their focus on technological invention. Some of the ideas Tarkovsky expresses in this film are further developed in his film Stalker (1979).