Chucky returns from the dead after being chopped up in Child's Play 3. He is reanimated by his girlfriend Tiffany (who is as sadistic and homicidal as Chucky), whom he lost contact with a decade ago when he, as Charles Lee Ray, transferred his soul into the Good Guy doll. After being resurrected, Chucky kills Tiffany's unreliable hired-assassin, Damien Baylock (a cameo appearance by Alexis Arquette) with a pillow after Tiffany chains him to a bed.
Tiffany asks Chucky if he was going to marry her since he left a diamond ring for her. Chucky tells her that he stole the ring from a rich old lady (who he killed and dumped in the river while he was still the "Lakeshore Strangler") because it is easily worth $5,000 to $6,000. Tiffany then asks, a little shaken, "So, you weren't going to ask me to marry you?" to which Chucky responds, "What, are you fuckin' nuts?" and laughs.
The heartbroken Tiffany drops Chucky into a playpen, intending to hold him prisoner as payback for the years she waited for him, with a doll in the shape of a bride. While Tiffany is in her bathtub, and watching Bride of Frankenstein (from which screenwriter Don Mancini actually got the idea for Bride of Chucky), Chucky escapes by using the diamond ring (which Tiffany put on the bride doll's necklace) to cut through the wooden bars. He then pushes Tiffany's television into her bathtub, electrocuting and killing her in the process. Using voodoo incantation., Chucky transfers Tiffany's soul into the bride doll. Tiffany becomes angry, slaps him, and the two dolls argue for awhile
After finally settling their differences, the two dolls decide that they must go to Charles Lee Ray's (Chucky's) grave to retrieve his magic amulet, because without it, Chucky and Tiffany will be permanently consigned to doll form. Tiffany hires her next-door neighbor, Jesse, to transport her and Chucky to the cemetery where Ray's body is interred. Jesse desperately needs the money promised by Tiffany, because he wants to run away with his girlfriend Jade, who happens to be the niece of a rather domineering local police chief. Chucky and Tiffany intend to appropriate Jesse's and Jade's bodies in the process. While driving, both Jade and Jessie suspect something is wrong. While Jessie and Jade are away, Chucky and Tiffany wound Jade's police uncle, rendering him unconscious. When the couple stop for supplies, a cop, who is an associate of Jade's uncle, slams Jesse into his van, and at the same time, Chucky secretly throws the weed into view. The cop prepares to arrest Jesse when Chucky leaps out of the van and stuffs a gas soaked shirt into the cop's car. Just as the cop notices the smoke, he sees Chucky and Tiffany waving at him as the car blows up. Several witnesses begin to panic, when Jade comes out of the store with food. As the couple is about to leave, a female yells that the two are responsible for the explosion. Jade and Jessie are now wanted by the police. Jessie and Jade both begin to question if the other is the murderer. Jessie decides that if they want to get away, they must leave the country. They head for Canada and get married to gain access to a couples-only hotel. As this is happening, Jade's uncle awakes and screams in horror, rolling out of the van where Chucky and Tiffany had hidden him. Before he can get away, Chucky begins stabbing him repeatedly, killing him.
Meanwhile, a seemingly happy, newly-married couple stop in on Jade and Jesse to say hi. The wife is impressed by the Tiffany doll, but disgusted at the sight of Chucky. While the man has Jesse and Jades attention, the wife steals their money. Tiffany seems offended, and feels that the wife is a slut who, according to her, "doesn't deserve to wear that ring". While the two thieves go off to their room to have sex, Tiffany sneaks into their room and throws a glass bottle into a mirror above the couple's bed, sending shards of glass down upon the couple, killing them. Chucky appears and is impressed with Tiffany, and the two engage in sex, causing Tiffany to become pregnant. Back in Jesse and Jade's room, Jesse calls his friend David, and talks about how he suspects Jade of killing the people, while Jade does the same. A maid (a cameo appearance by Kathy Najimy) walks into the blood-splattered room and discovers the bodies of the thieves. Jesse and Jade start to run, and are surprised to see David. While driving, David convinces both of them to stop accusing each other and work things out. Seeing what they had done, they resolve their differences. Soon David smells a foul odor and discovers Jade's dead uncle's body under a seat. He does nothing until Jade comes to give him a hug, David then grabs the gun off of the police chief's corpse and holds both of them at gun point, thinking that both of them are the killers. They stop the van and let David out, when Chucky leaps to life and shows himself to everyone. David is startled (and presumably believing that Jesse and Jade are innocent) and backs up, only to be run over by a semi-truck. Jade is horrified and blames Jesse for her uncle's death. Jesse drives off while Chucky and Tiffany shoot out the window as Jade opens it, making it look like she did it. On the radio, the couple are the prime suspects for the murders at the hotel. However, a radio announcement says that the fingerprints are found at the murder site have been positively identified as those of Charles Lee Ray's, despite his death in 1988. His corpse is due to be exhumed.
Because the police now have the van's license plate, Chucky makes Jesse get a new car. They hijack an RV, and kill the two owners. While Tiffany makes food for Chucky, and gives Jade a makeover, Jesse quips to Chucky that Tiffany isn't much of a homemaker, due to the fact there are so many dishes in the sink. Chucky tells her to clean up a little, and Jade, taking the lead, tells her, "You were nice enough to cook for him. The least he could do is wash a dish." (Earlier, while Tiffany was still human, she had told Jesse to treat his girlfriend right.) Tiffany throws the dishes at him, and starts a loud, violent argument. While they both fight, Jesse swerves the car, and Jade pushes Tiffany into the oven. Chucky, very angry that his wife has been hurt, starts shooting at Jade, but is pushed out the window by Jesse. The RV rolls violently off the road, and crashes.
Jade lays inside tied to a chair and sees that Tiffany, while badly burned, is still alive inside the oven. Jesse cuts Jade free and gets her out of the RV before a sparking wiring sets the vehicle on fire and it explodes. Jesse is blown clear, but Jade is taken hostage by Chucky. Jesse takes Tiffany by the hair and runs after them.
Chucky finds his open grave site, shoots the officer exhuming his body at the back of the head, and sends Jade in to open his coffin at gun point. She reluctantly retrieves the amulet, throwing it to him, and Jesse appears. Chucky agrees to let Jade go in exchange for Tiffany. As they cross paths, Tiffany tells Jade she's a very lucky girl. When the couples unite, Jade and Jesse cling desperately to each other, while Tiffany asks Chucky to catch her before collapsing. He only grimaces, letting her fall. Chucky then throws his knife at Jade, and Jesse turns her around, saving her life, the knife embedded in his back. Jade removes it, and being threatened, throws it back to Chucky.
Chucky ties the two of them together, and starts to perform the ritual as Tiffany sits nearby. He turns to her and says, "This is it." She tells him she loves him, and he says he knows. Tiffany goes on to say that they belong together, forever. He kisses her, and she takes his knife and stabs him in the back. He asks her why, and as she is touched by Jade and Jesse's love for each other, which makes her ashamed of herself, and also makes her realize they belong dead by saying, "Oh, Chucky, look at us. Don't you see? We belong dead. Good-bye darling. I'll see you in Hell."
She then goes to untie the two kids, who are relieved to still be alive. It is then that Chucky, feeling betrayed, attacks Tiffany with a shovel. She grabs one, and they fight. Chucky gets the upper hand, but she attacks him, trying to strangle him, and he stabs her through the chest. Jesse hits Chucky with a shovel throwing him into his grave, and takes the ladder away, trapping him in the 6-foot deep gravesite.
Chucky screams and curses, and just as Jade is about to shoot him, a detective (who appeared earlier on the TV news, during Tiffany's first death) arrives. He comes over to see what the commotion is about, and sees Chucky in the grave, running back and forth. Jade takes the cop's gun and screams "Don't move". Chucky then looks at her and says "Go ahead and shoot. I'll be back! I always come back!" Jade takes aim, Chucky sighs, and mutters, "But dying is such a bitch." Chucky is shot and his lifeless doll body lands onto his lifeless former body in the coffin.
After Chucky is killed, the detective calls in to say Jade and Jesse are innocent, and it wasn't them who committed all those murders. Jade and Jesse escape. As he waits for the rest of the unit, he walks around, finding Tiffany. He pokes her a few times, to make sure she is dead, and as he pulls back, Tiffany springs to life. She screams in agony, as something starts moving under her skirt. The detective screams in horror as a red, bloody, sharp-toothed baby appears, screeching, and attacks him.