Mothra (Japanese: モスラ, Hepburn: Mosura) is a 1961 Japanese kaiju film directed by Ishirō Honda, with special effects by Eiji Tsuburaya. Produced and distributed by Toho Co., Ltd, it is the first film in the Mothra franchise. The film stars Frankie Sakai, Hiroshi Koizumi, Kyōko Kagawa, Jerry Ito, and The Peanuts. In the film, an expedition to an irradiated island brings civilization in contact with a primitive native culture. When one sensationalist entrepreneur tries to exploit the islanders, their ancient deity arises in retaliation.

In 1960, producer Tomoyuki Tanaka hired Shin'ichirō Nakamura to write an original story for a new kaiju film. Co-written with Takehiko Fukunaga, and Yoshie Hotta, The Glowing Fairies and Mothra was serialized in a magazine in January 1961. Screenwriter Shinichi Sekizawa later adapted the story into a screenplay, patterning his version after King Kong (1933) and Godzilla (1954).

Mothra was theatrically released in Japan on July 30, 1961. An edited, English dubbed version was released theatrically in the United States on May 10, 1962, by Columbia Pictures. The titular monster, Mothra, would become Toho's second most popular kaiju character after Godzilla, appearing in eleven Godzilla films and her own trilogy in the 1990s.