Underground (Serbian: Подземље, Podzemlje) is a 1995 film directed by Emir Kusturica with a screenplay by Dušan Kovačević. It is also known by the subtitle Once Upon a Time There Was a Country (Serbian: Била једном једна земља, Bila jednom jedna zemlja), which was the title of the story shown on Serbian television as a 5-hour mini-series. The film uses the story of two friends to symbolically depict and satirise the history of Yugoslavia since the Second World War. The film was an international co-production between companies in the Federal Republic of Yugoslavia, France, Germany and Hungary.

Along with his 1988 film Time of the Gypsies, Underground is widely considered to be one of Kusturica's best films.

Buddies Marko and Blacky (Serbian: Црни, Crni), are hard to take seriously. All they want to do is party their lives away. However, the Nazi bombing of Belgrade changes everything and the resourceful duo comes up with an ingenious plan: one will stay aboveground while the other goes underground. The arrangement represents an ideal opportunity for all concerned: Blacky, his wife and the rest of their friends and neighbours will be protected from the chaos above, while Marko and Natalija (Blacky's sometime mistress, later Marko's wife) will sell the weapons they're making below. Everyone will share in the profits.

However, Marko neglects to mention to Blacky and the rest of the subterranean families that the Second World War has ended and he makes a profit on the black market selling the weapons. In the second part of the film, set in the early 1960s, Blacky, with his son Jovan emerge from underground; believing WWII is still on, they kill the lead 'Nazi' on the set of a film dramatising Blacky's own exploits twenty years earlier. In the manhunt Jovan drowns but Blacky escapes. The final section, set in 1992 at the height of the Yugoslav wars, sees Blacky as an embittered yet still patriotic warlord; he inadvertently orders the execution of Marko and Natalija who are still making a living as war profiteers, running guns for the various factions. In a surreal ending, all friends and family, living and dead, are reunited at Jovan’s wedding.