Carrie White is a shy 16-year-old girl who lives with her fanatically religious and abusive mother, Margaret. Carrie is unpopular at school and is often ostracized by her peers.
Carrie experiences her first menstrual period as she showers with her female classmates after gym class. Unaware of what is happening to her, she panics and desperately pleads for help, believing herself to be bleeding to death. The other girls—led by the arrogant, popular and beautiful Chris Hargensen, who frequently bullies Carrie—pelt Carrie with tampons, laughing and chanting “Plug It Up! Plug It Up!” A light bulb mysteriously breaks as Carrie reaches the height of her panic. Gym teacher Miss Collins breaks up the commotion, consoles Carrie, and tells her what menstruation is.
Later, as the principal dismisses Carrie from school, Carrie becomes frustrated at both cigarette smoke emanating from an ashtray and at the principal repeatedly referring to her by the name “Cassie”; she causes the ashtray to flip from his desk and shatter. On Carrie’s way home, a young boy teases her, and she makes him fall off his bicycle with just one look.
At home, Carrie is abused by Margaret, who uses fake Bible quotes to rant about menstruation being the result of sinful thoughts, and Eve being “weak”. Carrie is dragged and locked in a small, specially-decorated “prayer closet” and forced to pray for forgiveness. When she is allowed to go to her room, she gazes into her reflection, causing the mirror to shatter. Shocked, Carrie begins to assume she may have some kind of supernatural power.
Carrie’s classmate Sue feels guilty for participating in the locker room antics, so she arranges for her boyfriend—the handsome and popular Tommy—to invite Carrie to the upcoming prom. Carrie is reluctant to accept, but is encouraged to do so by Miss Collins. Chris furiously throws a tantrum and defiantly skips her detention for tormenting Carrie, resulting in her getting slapped in the face by Miss Collins. Swearing vengeance, Chris recruits her delinquent boyfriend Billy to play a prank on Carrie. They slaughter pigs from a nearby farm and place a bucket of pigs’ blood above the stage at the school’s gymnasium. Margaret discovers Carrie’s prom plans and attempts to abuse her again. Having researched her telekinesis, Carrie asserts her power and stands up to her mother. Margaret responds by accusing Carrie of being a satanic witch.
At the prom, Carrie finds acceptance among her peers and shares a kiss with Tommy. Chris’s friend Norma rigs the election and Carrie is crowned Prom Queen. However, Carrie’s joy is cut short when Chris pulls a rope to dump the pig’s blood on her. Chris and Billy escape through a back door while the bucket falls on Tommy’s head, knocking him unconscious. The audience is left shocked and speechless, but Carrie hallucinates that everyone in the gymnasium is laughing at her, even Miss Collins. Enraged, Carrie goes into a silent-psychotic breakdown which causes her to unleash telekinetic fury upon the crowd. The doors slam shut, a high-pressure water hose assaults many people (including Norma, who is knocked unconscious), the principal is electrocuted, Miss Collins is crushed to death, and Carrie’s English teacher is electrocuted so badly that his body erupts in flames, setting the gym on fire. As the inferno rages, the enraged and entranced Carrie calmly walks out and locks the remaining students inside, sealing their fates. Later, Chris and Billy—who witnessed the entire episode—attempt to run over Carrie with a car. Carrie causes their car to flip and explode, killing them both in a burst of flames.
When Carrie reaches home, Margaret reveals that Carrie is the result of a rape committed by her drunken father and that Margaret enjoyed the experience. Margaret says that sin never dies; as she comforts Carrie, Margaret stabs her in the back and chases her around the house with a knife. In self-defense, Carrie causes knives and sharp kitchen utensils to fly through the air and crucify Margaret. Overcome with anguish over her actions, Carrie loses control of her powers and incinerates the house while she and her mother are still inside.
Weeks later, Sue—the only survivor of the prom massacre—has a nightmare in which she lays flowers on the remains of Carrie’s home. A “for sale” sign has been vandalized with the phrase “Carrie White burns in Hell!” Suddenly, Carrie’s bloody arm reaches from beneath the rubble and grabs Sue’s forearm. Sue wakes up screaming as her mother comforts her.