Godzilla (ゴジラ, Gojira^?) ( /ɡɒdˈzɪlə/; [ɡodʑiɽa] ( listen)) is a daikaijū, a Japanese movie monster, first appearing in Ishirō Honda's 1954 film Godzilla. Since then, Godzilla has gone on to become a worldwide pop culture icon starring in 28 films produced by Toho Co., Ltd. The monster has appeared in numerous other media incarnations including video games, novels, comic books, television series, a 1998 American remake and a second American version is in development.

With the atomic bombings of Hiroshima and Nagasaki and the Daigo Fukuryū Maru incident still fresh in the Japanese consciousness, Godzilla was conceived as a monster created by nuclear detonations and a metaphor for nuclear weapons in general. As the film series expanded, some stories took on less serious undertones portraying Godzilla as a hero while other plots still portrayed him as a destructive monster; sometimes the lesser of two threats who plays the defender by default but is still a danger to humanity.

Gojira (ゴジラ^?) is a portmanteau of the Japanese words: gorira (ゴリラ^?, "gorilla"), and kujira (鯨（クジラ）^?, "whale"), which is fitting because in one planning stage, Godzilla was described as "a cross between a gorilla and a whale", alluding to his size, power and aquatic origin. A popular story is that "Gojira" was actually the nickname of a corpulent stagehand at Toho Studio. The story has not been verified, however, and in the fifty years since the film's original release, no one claiming to be the rumored employee has ever stepped forward and no photographs have ever surfaced. Kimi Honda (the widow of Ishiro Honda) always suspected that the man never existed as she mentioned in a 1998 interview that "the backstage boys at Toho loved to joke around with tall stories".