Godzilla (Japanese: ゴジラ, Hepburn: Gojira, ; [ɡoꜜ(d)ʑiɾa] ) is a fictional monster, or kaiju, that debuted in the eponymous 1954 film, directed and co-written by Ishirō Honda. The character has since become an international pop culture icon, appearing in various media: 33 Japanese films produced by Toho Co., Ltd., five American films and numerous video games, novels, comic books and television shows. Godzilla has been dubbed the "King of the Monsters", an epithet first used in Godzilla, King of the Monsters! (1956), the American localization of the 1954 film.

Godzilla is a prehistoric reptilian monster awakened and empowered by nuclear radiation. With the nuclear bombings of Hiroshima and Nagasaki and the Lucky Dragon 5 incident still fresh in the Japanese consciousness, Godzilla was conceived as a metaphor for nuclear weapons. Others have suggested that Godzilla is a metaphor for the United States, a giant beast woken from its slumber which then takes terrible vengeance on Japan. As the film series expanded, some stories took on less serious undertones, portraying Godzilla as an antihero, or a lesser threat who defends humanity. Later films address disparate themes and commentary including Japan's apathy and neglect of its imperial past, natural disasters, and the human condition.

Godzilla has been featured alongside many supporting characters. It has faced human opponents such as the JSDF, or other monsters, including King Ghidorah, Mechagodzilla and Gigan. Godzilla sometimes has allies, such as Rodan, Mothra and Anguirus, and offspring, such as Minilla and Godzilla Junior. Godzilla has also fought characters from other franchises in crossover media, such as King Kong, as well as various Marvel Comics characters, including S.H.I.E.L.D., the Fantastic Four and the Avengers.