The Amazing Colossal Man (also known as The Colossal Man) is a 1957 American black-and-white science fiction film from American International Pictures, produced and directed by Bert I. Gordon, that stars Glenn Langan, Cathy Downs, William Hudson, and Larry Thor. It is an uncredited adaptation of Homer Eon Flint‘s 1928 short science fiction novel The Nth Man. It was theatrically released by AIP as a double feature with Cat Girl.

The film’s storyline concerns a U.S. Army Lt. Colonel who survives a plutonium explosion and grows 8 to 10 feet a day reaching 60 feet tall

During the 1960s, the film was syndicated to television by American International Television. Both it and its sequel, War of the Colossal Beast (1958), were mocked on Mystery Science Theater 3000.