Blood Bath is a 1966 American horror film directed by Jack Hill and Stephanie Rothman and starring William Campbell, Linda Saunders, Marissa Mathes, and Sid Haig. The film concerns a mad painter of weird art who turns into a vampire-like man (with different features) by night, apparently as a result of a family curse, and believes that he has found his reincarnated mistress in the person of an avant-garde ballerina.

Blood Bath had a complex and troubled production history, marked by various cuts and reshoots. In 1963 Roger Corman had co-produced a Yugoslavia-made spy thriller called Operation: Titian, but the film was deemed unreleasable. Corman purchased the rights to another film and assigned writer-director Jack Hill to write a new script. This time, it was a horror film that incorporated the previous footage from Operation: Titian. Hill wrote and directed numerous horror sequences that were edited into the film, and it was re-titled Portrait in Terror. Still unsatisfied with the completed product, Corman hired Stephanie Rothman to film additional sequences that were also added. This cobbled-together feature was given a brief theatrical release by American International Pictures under the title Blood Bath, with screenplay and directorial credit jointly shared by Hill and Rothman. An additional version of the film was made for television and re-titled Track of the Vampire.