Cthulhu is a 2007 American horror film directed by Dan Gildark and co-written by Grant Cogswell and Daniel Gildark. The film is loosely based on the novella The Shadow over Innsmouth (1936) by H. P. Lovecraft.

The film moves the story from New England to the Pacific Northwest. The film is notable among works adapted from Lovecraft's work for having a gay protagonist. Screenwriter Grant Cogswell explained that he and Gildark chose to exploit the metaphor for the horror faced by a gay person returning for a relative's funeral and having to face the horrors of small-town life.

The film premiered June 14, 2007, at the Seattle International Film Festival and officially opened in select theatrical venues August 22, 2008.