Saw III is a 2006 American horror film directed by Darren Lynn Bousman from a screenplay by Leigh Whannell and a story by Whannell and James Wan. A sequel to Saw II (2005) and the third installment in the Saw film series, it stars Tobin Bell, Shawnee Smith, Angus Macfadyen, Bahar Soomekh, and Dina Meyer.

In the film, John Kramer (Bell), who is known as the Jigsaw Killer and forces his victims to participate in deadly games in order to test their will to live, puts a man named Jeff (Macfadyen) through a series of tests of his ability to forgive, after Jeff's son was killed by a drunk driver. Meanwhile, John's apprentice Amanda (Smith) has kidnapped a doctor named Lynn (Soomekh) and tasked her with keeping John, who is bedridden with terminal cancer, alive long enough for Jeff to complete his game.

Much like its predecessor, the film was immediately green-lit after the successful opening weekend of the prior film. Filming took place in Toronto from May to June 2006. Whannell aimed to make the story more emotional than previous installments, particularly with the Amanda and Jigsaw storyline. The film is dedicated to producer Gregg Hoffman, who died on December 4, 2005.

Saw III was released in the United States on October 27, 2006, by Lionsgate Films. It was a financial success, opening to $33.6 million and grossing $80.2 million in the United States and Canada. It is the highest-grossing film of the series in the international market and the highest-grossing film in the series overall. It received negative reviews from critics. Bell was nominated for "Best Villain" at the 2007 MTV Movie Awards and the film received nominations for a Saturn Award as "Best Horror Film". The film was released to DVD and Blu-ray on January 23, 2007 where it topped the charts selling 2.5 million units in its first week. A sequel, Saw IV, was released in 2007.

After being imprisoned in the bathroom, Detective Eric Matthews breaks his foot with a toilet lid to escape. Six months later, the scene of a Jigsaw game is discovered by Officer Rigg's SWAT team. The victim, Troy, had to rip chains from his body to escape a bomb. Detective Allison Kerry points out that the room's exit was welded shut, breaking Jigsaw's modus operandi of allowing his victims an opportunity to survive. Kerry is abducted and awakens in a harness hooked into her ribs. She retrieves the key from a beaker of acid as instructed, but opening the lock does not keep the trap from killing her.

Dr. Lynn Denlon is abducted from the hospital she works at and brought to the now bedridden John Kramer. His apprentice, Amanda, locks a collar armed with five shotgun shells around Lynn's neck that is connected to John's heart rate monitor and will detonate if she moves out of range or John dies. Lynn is instructed by Amanda to keep him alive until another test subject has completed his game; the victim, Jeff, a grief-stricken father who was consumed with vengeance after the death of his son Dylan in a drunk driving crash years earlier, must undergo a series of tests at an abandoned meatpacking plant to confront those involved in the case.

Jeff's first test leads him into a meat freezer where he finds Danica, the only witness to the crash (who refused to testify in court) completely naked and chained to a metal frame inside the plant's freezer, with nozzles inside the frame spraying her with water to quicken her hypothermia. Jeff retrieves the key after Danica persuades him to help her, but she freezes to death before he can do so. In his next test, Judge Halden, who passed a lenient sentence on the driver who caused Dylan's death, is chained at the neck to the bottom of a vat. Rotting pig carcasses are dropped into a grinder that slowly fill the vat until Jeff saves him by burning Dylan's belongings in an incinerator to retrieve a key. His third test involves Timothy, the driver who killed Dylan, who is strapped to a machine that will slowly twist and snap his limbs and then his head. The key is tied to the trigger of an enclosed shotgun that goes off after Jeff retrieves it, killing Halden. Jeff cries out twice that he forgives Timothy, but even so, he cannot save him in time; the machine twists and breaks Timothy's neck.

Lynn is forced to perform an improvised surgery to relieve pressure on John's brain. The surgery is successful, and Lynn convinces John to order Amanda to remove the collar. However, Amanda refuses and threatens Lynn's life, having become jealous of her interactions with John. John pleads with Amanda, who admits that she no longer believes in his philosophy and had rigged Troy and Kerry's traps. Refusing to listen to John's warnings, Amanda shoots Lynn just as Jeff arrives. Jeff, who is revealed to be Lynn's husband, retaliates by shooting Amanda with a gun provided by John after his tests. As Amanda dies, John reveals that Lynn's test was actually hers: John was aware of her motives and unwilling to allow a murderer to continue his legacy. He then addresses Jeff, offering to call an ambulance for Lynn if he has learned everything from his ordeal, and accept one last test: either killing John or forgiving him. In response, Jeff slashes John's throat with a power saw, activating Lynn's collar as the room is sealed shut. Before dying, John takes out a tape recorder to inform Jeff that his daughter, Corbett, is also captured and no one but him knows where she's being held.