Margaret White (née Brigham) is a fictional character created by American author Stephen King in his first published horror novel, Carrie (1974), where she is the main antagonist.

She is a delusional and mentally unstable religious fanatic, who believes almost everything is a sin to God, especially when related to female anatomy or sexual intercourse.

Her father was killed in a gun battle and she began attending a fundamentalist church group to deal with the loss, quickly becoming a religious fanatic.

Whenever Margaret believed that Carrie had sinned at school, she would throw her in a specially decorated closet to pray for forgiveness (out of no fault of her own), usually leaving her there for several hours or even days as a punishment.

Once Carrie makes her own dress, Margaret insists that they burn it and pray for forgiveness, disapproving of the fact that it shows cleavage.

Once Carrie arrives home, having telekinetically destroyed the high school and everything else in the town after falling victim to a cruel prank, both are surprised to find out that they each intend to kill the other.

Carrie kills her mother by telekinetically slowing down her heart to a stop; Margaret recites the Lord's Prayer as she dies.

As in the novel, Margaret reveals that she had sex with Ralph twice: once prior to marriage (after which she wanted to kill herself), and once more after they were married, when he was drunk and forced himself on her, leading to the conception of Carrie.

After Carrie returns home after unleashing her powers at the prom (killing almost everyone there), Margaret, who has lit thousands of candles all over the house, tells her about the night she was conceived by marital rape, then stabs her in the back with the butcher knife while leading her in the Lord's Prayer convincing that Satan has taken control of Carrie.As Carrie tries to crawl away, Margaret makes a cross motion with the knife and stalks her through the house with a delirious look in her eyes.

Cook withdrew after three weeks of performances and was replaced when the show transferred to Broadway by Betty Buckley, who had appeared in the original film as Carrie's gym teacher.

Margaret even shows remorse after beating and locking Carrie in the prayer closet (cellar in the musical) after the shower incident.

Her songs include "Open Your Heart", "And Eve Was Weak", "Evening Prayers", and "I Remember How Those Boys Could Dance" (duets with Linzi Hateley as Carrie) and the solo "When There's No One".

The lyrics of the first act finale imply the marital rape described in the novel, as Margaret recalls Carrie's father attempting to seduce her while they were dating, culminating on a night when "he took me and touched me; I tried to fight".

While it closely resembles Piper Laurie's interpretation in evidence of the character dressing in black, Moore's portrayal of Margaret has her showing genuine love for Carrie and being the proprietor of a tailoring business.