One year after the events in New York, Jason Voorhees has resurfaced in Crystal Lake but falls into a trap set up by the FBI. He is destroyed by a grenade explosion. A mysterious person in the forest surveys what has just happened and says "I don't think so."
Jason's remains are sent to a morgue. The coroner conducting the autopsy becomes hypnotized by Jason's heart and is compelled to eat it. This causes the coroner to be possessed by the demonic spirit of Jason. The now possessed coroner begins a killing spree en route to Crystal Lake. Unstated in the film, Jason's supernatural abilities allow him to switch from body to body by eating them or their hearts.
After a confrontation between Creighton Duke and Diana Kimble, Creighton warns Diana that Jason will come to get her and her daughter, Jessica Kimble. Diana tells Jessica's former boyfriend Steven Freeman to meet her at their house to discuss some issues in private. Come nightfall, Steven picks up a few hitchhikers on his way to Diana's house and drops them off at Crystal Lake, where they have sex and get murdered by the recently arrived Jason. After arriving at her house, Steven hears Diana screaming and goes to her aid to find her being assaulted by Josh, a fellow policeman who earlier, had been eaten by the "coroner" and had Jason's spirit transferred into his body, as illustrated by Creighton Duke. Jason then finally kills Diana.
Steven is falsely accused and arrested, meeting the mysterious person, Creighton Duke, in jail. Duke claims that only members of Jason's bloodline can truly kill him for good. Therefore if he transfers the creature into a member of his family, he will be "reborn" back to his old form. Creighton goes on to tell Steven that the only living relatives of Jason are his half-sister Diana, her daughter Jessica, and her infant daughter Stephanie.
Unscrupulous news anchor Robert Campbell, who is dating Jessica, steals Diana's body, planting it in the house for an upcoming investigative show to boost his ratings. Jason bursts in and possesses Robert before leaving with Steven in pursuit. Jessica, who is unaware that her boyfriend is the undead killer, is attacked by him so he can be reborn through her but is disrupted by Steven, who manages to stop him and get Jessica into a car. He runs over Jason and explains the situation, but Jessica does not believe him and throws him out of the car and goes to the police.
Steven turns himself into the police and arrives at the station as Jason does; he frees himself again to protect Jessica, who now realizes the truth. In the chaos, Creighton makes his escape. Steven and Jessica discover a note from Creighton, telling them that he has Stephanie and ordering Jessica to meet him at the Voorhees house alone.
Jessica meets Creighton at the Voorhees house. Creighton throws her a knife, and when she catches it, the knife turns into a mystical dagger. Jason tries to possess Stephanie, but Steven arrives and severs his neck with a machete. A creature crawls out of his neck, and makes its way to the basement, where Diana's body was planted. Jason explodes through the floor in his original body.
As Jessica attempts to retrieve the dagger, the two men alternately fight with Jason. Duke is killed by Jason, and the fight between Jason and Steven ends up outside in the yard. As Jason prepares to finish him, Jessica jumps behind him and stabs him in the chest. This causes Jason to be dragged to Hell.
As the couple walks off with their daughter, a dog appears and unearths Jason's mask. Suddenly, the claw-glove hand of Freddy Krueger emerges from the ground and drags the mask down into Hell with an evil laughter in the background, which sets the events for a violent conflict between the two killers.
- Kane Hodder as Jason Voorhees/Guard/Freddy Krueger's claw
- John D. LeMay as Steven Freeman
- Kari Keegan as Jessica Kimble
- Steven Williams as Creighton Duke
- Allison Smith as Vicki
- Steven Culp as Robert Campbell (who later becomes Jason)
- Billy Green Bush as Sheriff Landis
- Erin Gray as Diana Kimble
- Rusty Schwimmer as Joey B.
- Leslie Jordan as Shelby
- Josh Brennan as Deputy Josh (who later becomes Jason)
- Kipp Marcus as Randy Parker (who later becomes Jason)
- Richard Gant as Phil the Coroner (who later becomes Jason)
- Gino Kane as Ward
- Julie Michaels as Elizabeth Marcus
- Paul Devine as Paul
- Michelle Clunie as Deborah
John D. LeMay is one of the only two actors from the TV series to appear in the film series; the other is John Shepard, who also played Tommy Jarvis in Friday the 13th: A New Beginning.
The film debuted in U.S. theaters on Friday, August 13, 1993 to a weekend box office total of $7.6 million. It faced strong competition at the time of its release from other high-profile horror film releases such as the Stephen King adaptation Needful Things and the killer canine thriller Man's Best Friend. The film would go on to gross a final domestic total of $15.9 million, placing at number 86 on the list of the year's Top 100 earners.
As with the other Friday the 13th films, many critics panned the film. It maintains a 24% approval rating on review aggregate site Rotten Tomatoes based on 17 reviews. The main criticism is the idea of Jason "possessing" the body of people to kill his victims being too outlandish, and simply being another formulaic entry in the series with poor acting and plot holes. However, The Final Friday was received significantly better than its 1989 predecessor, Jason Takes Manhattan.