Saw IV is a 2007 horror film directed by Darren Lynn Bousman from a screenplay by Patrick Melton and Marcus Dunstan, and a story by Melton, Dunstan, and Thomas Fenton. It is the fourth installment in the Saw film series and a sequel to 2006's Saw III. The film stars Tobin Bell, Scott Patterson, Costas Mandylor, Betsy Russell, and Lyriq Bent.

The film picks up where the previous film left off, with the death of John Kramer. However, it is revealed that John had planned for his death and left behind a series of recordings and clues that would lead investigators to his final game. As the detectives try to unravel the mystery of John's final game, they are drawn into a web of deceit and deception that reveals more of the motives behind his lethal games.

Saw IV was the first film in the franchise to not be written by Leigh Whannell or James Wan. It was released by Lionsgate Films in the United States on October 26, 2007. It received mostly negative reviews from critics and grossed $139 million worldwide. A sequel, Saw V, was released in 2008.