In 1979 Chamberlain, Maine, Carietta "Carrie" White is a 16-year-old girl ridiculed for her weight, frumpy appearance and unusual religious beliefs instilled by her despotic mother, Margaret. One day, Carrie has her first period while showering in the girls' locker room after physical education class. Carrie is terrified, having no understanding of menstruation as her mother, who finds sexuality sinful, never taught her. While Carrie panics, her classmates, led by a wealthy, popular girl named Chris Hargensen, mock and throw tampons and sanitary napkins at her. The gym teacher, Rita Desjardin, has Carrie compose herself and sends her home. On the way, Carrie practices her unusual ability to control objects from a distance. She recalls using this power when she was three to cause stones to fall from the sky. Once Carrie gets home, Margaret furiously accuses Carrie of sin and locks her in a closet.
The next day, Desjardin reprimands the girls who bullied Carrie and gives them a week's detention; Chris refuses to comply and is punished with suspension and exclusion from the prom. After her influential father fails to reinstate her, Chris decides to take revenge on Carrie. Sue Snell, another popular girl who bullied Carrie in the locker room, grows remorseful, and asks her boyfriend, Tommy Ross, to invite Carrie to the prom instead. Carrie is suspicious, but accepts and begins sewing a prom dress. Meanwhile, Chris persuades her boyfriend Billy Nolan and his gang of greasers to gather two buckets of pig blood as she prepares to rig the prom queen election in Carrie's favor.
The prom initially goes well for Carrie: Tommy's friends are welcoming, and Tommy finds he is attracted to Carrie as a friend. Chris successfully rigs the election, and Carrie and Tommy are elected prom queen and king. However, at the moment of the coronation, Chris, from outside, dumps the pig blood onto Carrie's and Tommy's heads. Tommy is knocked unconscious by one of the buckets and dies. The sight of Carrie drenched in blood invokes laughter from the audience. Carrie leaves the building, humiliated.
Outside, Carrie remembers her telekinesis and decides to enact vengeance on her tormentors. Using her powers, she seals the gym, which activates the sprinkler system, inadvertently electrocuting many of her classmates, and causing a fire that eventually ignites the school's fuel tanks, destroying the building in a massive explosion. Only a few lucky staff and students escape. Carrie, overwhelmed by rage, thwarts any incoming effort to fight the fire by opening the hydrants within the school's vicinity, then destroys gas stations and cuts power lines on her way home. She unleashes her telekinetic powers on the town, destroying several buildings and killing hundreds of people. As she does this, she broadcasts a telepathic message, showing the townspeople that the carnage was caused by her.
Carrie returns home to confront Margaret, who believes Carrie has been possessed by Satan and must be killed. Margaret tells her that her conception was a result of what may have been marital rape. She stabs Carrie in the shoulder with a kitchen knife, and Carrie halts Margaret's heart as she says a prayer. Mortally wounded, Carrie makes her way to the roadhouse where she was conceived. She sees Chris and Billy leaving, having been informed of the destruction by one of Billy's friends. After Billy attempts to run over Carrie, she takes control of his car and sends it into a wall, killing Billy and Chris.
Sue, who has been following Carrie's "broadcast", finds her collapsed in the parking lot, bleeding from the knife wound. The two have a brief telepathic conversation. Carrie had believed that Sue and Tommy had set up the prank, but realizes they were innocent. Carrie dies, crying out for her mother.
A state of emergency is declared and the survivors make plans to relocate. Chamberlain foresees desolation in spite of the government assisting on rehabilitating the worker districts. Desjardin and the school's principal blame themselves for the disaster and resign from teaching. Sue publishes a memoir based on her experiences. A "White Committee" report investigating paranormal abilities concludes that there will be others like Carrie. An Appalachian woman enthusiastically writes to her sister about her baby daughter's telekinetic powers and reminisces about their grandmother, who had similar abilities.
