Frankenstein vs. Baragon (Japanese: フランケンシュタイン対地底怪獣バラゴン, Hepburn: Furankenshutain tai Chitei Kaijū Baragon, lit. 'Frankenstein vs. Subterranean Monster Baragon') is a 1965 kaiju film directed by Ishirō Honda, with special effects by Eiji Tsuburaya. The film stars Nick Adams, Kumi Mizuno and Tadao Takashima, with Koji Furuhata as Frankenstein and Haruo Nakajima as Baragon. An international co-production of Japan and the United States, it was the first collaboration between Toho and Henry G. Saperstein. In the film, scientists investigate the origins of a mysterious monster boy Frankenstein and his resistance to radiation that makes him grow to monstrous size, while another monster Baragon ravages the countryside.

Frankenstein vs. Baragon was theatrically released in Japan on August 8, 1965, followed by a theatrical release in the United States on July 8, 1966 by American International Pictures as Frankenstein Conquers the World. The film was followed by The War of the Gargantuas, released on July 31, 1966.