The Monster That Challenged the World is a 1957 black-and-white science-fiction monster film from Gramercy Pictures, produced by Arthur Gardner, Jules V. Levy, and Arnold Laven (who also directed), and starring Tim Holt and Audrey Dalton. The film was distributed by United Artists as the top half of a double feature with The Vampire. The film concerns an army of giant molluscs that emerge from California's Salton Sea.