Carnosaur is a 1993 American science fiction horror film written and directed by Adam Simon. The film stars Diane Ladd, Raphael Sbarge, Jennifer Runyon, and Harrison Page. Loosely based on the 1984 John Brosnan novel of the same name, it follows characters Doc Smith and Ann Thrush in their efforts to thwart Dr. Jane Tiptree's plan to exterminate the human race with a lethal virus and replace them with her own genetically created dinosaurs.

Roger Corman acquired the rights to Brosnan's novel in 1991 and the project entered production two years later to capitalize on an extensive marketing campaign used to promote Jurassic Park. Simon was hired to direct Carnosaur and is credited with writing the screenplay, reworking most of the plot elements of the novel. Afforded an $850,000 budget, the special effects were completed with models and animatronics largely designed by John Carl Buechler.

Carnosaur was released on May 14, 1993, in Ogden, Utah, and then released regionally in the United States one day later and grossed $1.8 million. The film was panned by critics. Roger Ebert named it the worst movie of 1993, though his colleague Gene Siskel liked the film. The film has since gained a cult following as a "mockbuster". Carnosaur has spawned a film series and was followed by two sequels, Carnosaur 2 (1995) and Carnosaur 3: Primal Species (1996); the series also includes two official spin-offs Raptor (2001) and The Eden Formula (2006).