Mothra 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.

Kaiju is a Japanese term that is commonly associated with media involving giant monsters. A subgenre of science fiction, it was created by Eiji Tsuburaya and Ishirō Honda. The term can also refer to the giant monsters themselves, which are usually depicted attacking major cities and battling either the military or other monsters.