Gappa (Japanese: 大巨獣ガッパ, Hepburn: Daikyojū Gappa, lit. 'Giant Beast Gappa') is a 1967 Japanese kaiju film directed by Haruyasu Noguchi. The film is about a group of Japanese reporters who discover an infant monster called a Gappa on Obelisk Island. The reporters cage the creature and take it to Japan where it becomes a media attraction. This angers the natives of the island and Gappa's full-grown parents, who head toward Japan to find their child. Its plot virtually duplicates that of the 1961 British film Gorgo.

The film was released theatrically as Daikyojū Gappa in Japan in 1967, but only received a direct-to-television release in the United States as Monster from a Prehistoric Planet. It received positive reviews from Variety and Phil Hardy.

Certain shots of the Gappas attacking Japan were used in the 1991 Red Dwarf episode "Meltdown".