300 is a 2006 American epic historical action film directed by Zack Snyder, who co-wrote the screenplay with Kurt Johnstad and Michael B. Gordon, based on the 1998 comic book limited series of the same name by Frank Miller and Lynn Varley. The film, like its source material, is a fictionalized retelling of the Battle of Thermopylae in the Greco-Persian Wars. The plot revolves around King Leonidas (Gerard Butler), who leads 300 Spartans into battle against the Persian "God-King" Xerxes (Rodrigo Santoro) and his invading army of more than 300,000 soldiers. As the battle rages, Queen Gorgo (Lena Headey) attempts to rally support in Sparta for her husband. The film also features Michael Fassbender in his film debut.

The story is framed by a voice-over narrative by the Spartan soldier Dilios (David Wenham). Through this narrative technique, various fantastical creatures are introduced, placing 300 within the genre of historical fantasy. 300 was filmed mostly with a superimposition chroma key technique to replicate the imagery of the original comics.

An unfinished cut of 300 premiered at the Austin Butt-Numb-A-Thon on December 9, 2006. The completed film then premiered at the Berlin International Film Festival on February 14, 2007, before being released in both conventional and IMAX screens in the United States on March 9, 2007, and on home media on July 31, 2007. The film received mixed reviews from critics, who praised its visuals and style but criticized its historical inaccuracies, including its depiction of the Persians, which some characterized as bigoted or Persophobic. Grossing over $456 million, the film's opening was the 24th-largest in box office history at the time, and became the tenth highest-grossing film of 2007. The film earned a leading ten nominations at the 34th Saturn Awards, winning two for Best Action, Adventure, or Thriller Film and Best Director (for Snyder). A sequel, titled Rise of an Empire, based on Miller's previously unpublished graphic novel prequel Xerxes, was released on March 7, 2014.