Katie Scarlett, or Scarlett as everyone but her father calls her (she is named for his mother, chapter 2, Gone With the Wind) has dark hair and a slim frame. She is an atypical protagonist, especially as a female romantic lead in fiction. When the novel opens, Scarlett is sixteen. She is vain, self-centered, somewhat spoiled, can be insecure, and has an intelligent, bright mind. She stands out in that she is smarter than and very much unlike the typical party-going Southern belles around her. She can be a high-strung busybody, but for someone so smart, with men she loves, she can go into a mode where she is both babyish and overthinks little things. On the outside she seems charming, busy, good, and smart; but on the inside she is insecure and just wants the affection of her neighbor, Ashley Wilkes. She makes surface efforts to live up to the expectations her culture demands, but fears discovery by society of her true self. Scarlett has deep affection for Ashley, and wishes to marry him, despite a tradition in his family to marry cousins. Scarlett's motivation in the early part of the novel center on her desire to win the affection of Ashley, despite the fact that both of them marry others. Rhett Butler, an older bachelor, overhears Scarlett expressing her true feelings to Ashley, during a barbecue at Ashley's home. Rhett admires and is interested in the willful Scarlett, and pursues her through a romantic friendship when she becomes widowed, helping her to ignore Southern conventions and become active in society again. The Civil War is ultimately blamed by disapproving society, and Scarlett finds friendship with Rhett liberating.
After the War, Scarlett's character hardens, when she is burdened by her family, servants, the Wilkes family, and the fear of homelessness and starvation. This causes her to become extremely money-conscious and materialistic. Her motivation is to assure that no one close to her faces the threat of starvation or being a burden to others outside the family. As such, she engages in controversial business practices and exploits convict labor in order to make her lumber business, bought and run in defiance of her seconds husband's wishes, have a higher profit margin. After she becomes widowed again, she marries Rhett Butler for "fun" and because he is very wealthy.
Unfortunately, Scarlett is too insecure and vain to realize her pursuit of Ashley was misdirected until the climax of the novel. With the death of Melanie Wilkes, she realizes her pursuit of Ashley was in vain and he did not return her affection. She realizes she never really loved Ashley and that she has loved Rhett Butler for some time. She pursues Rhett from Melanie's deathbed to their home in the neighborhood, only to discover he has given up on receiving a return of affection from Scarlett and is preparing to leave her. In a reminder of how important her homeland is to her, Scarlett decides to return to the family plantation, Tara, to rest and set her plans to attract Rhett anew.
On the eve of the American Civil War in 1861, Scarlett O'Hara lives at Tara, her family's cotton plantation in Georgia, with her parents and two sisters. Scarlett learns that Ashley Wilkes—whom she secretly loves—is to be married to his cousin, Melanie Hamilton, and the engagement is to be announced the next day at a barbecue at Ashley's home, the nearby plantation Twelve Oaks.
At the Twelve Oaks party, Scarlett notices that she is being admired by Rhett Butler, who has been disowned by his family. Rhett finds himself in further disfavor among the male guests when, during a discussion of the probability of war, he states that the South has no chance against the superior numbers and industrial might of the North. Scarlett secretly confesses to Ashley that she loves him, but he rebuffs her by responding that he and the sweet Melanie are more compatible. Afterwards, Rhett reveals to Scarlett he has overheard their conversation, but promises to keep her secret. The barbecue is disrupted by the declaration of war and the men rush to enlist. As Scarlett watches Ashley kiss Melanie goodbye from the upstairs window, Melanie's shy younger brother Charles asks for her hand in marriage before he goes. Though she does not love him, Scarlett consents, and they are married before he leaves to fight.
Scarlett is quickly widowed when Charles dies from a bout of pneumonia and measles while serving in the Confederate Army. Scarlett's mother sends her to the Hamilton home in Atlanta to cheer her up, although the O'Haras' outspoken housemaid Mammy tells Scarlett she knows she is going there only to wait for Ashley's return. Scarlett, who should not attend a party while in deep mourning, attends a charity bazaar in Atlanta with Melanie. There, Scarlett is the object of shocked comments on the part of the elderly women who represent proper Atlanta society. Rhett, now a blockade runner for the Confederacy, makes a surprise appearance. To raise money for the Confederate war effort, gentlemen are invited to offer bids for ladies to dance with them. Rhett makes an inordinately large bid for Scarlett and, to the disapproval of the guests, Scarlett agrees to dance with him. As they dance, Rhett tells her he intends to win her, which she says will never happen.
The tide of war turns against the Confederacy after the Battle of Gettysburg in which many of the men of Scarlett's town are killed. Scarlett makes another unsuccessful appeal to Ashley while he is visiting on Christmas furlough, although they do share a private and passionate kiss in the parlor on Christmas Day, just before he returns to war.
Eight months later, as the city is besieged by the Union Army in the Atlanta Campaign, Melanie goes into premature and difficult labor. Keeping her promise to Ashley to take care of Melanie, Scarlett and her young house servant Prissy must deliver the child without medical assistance. Scarlett calls upon Rhett to bring her home to Tara immediately with Melanie, Prissy, and the baby. He appears with a horse and wagon and takes them out of the city through the burning depot and warehouse district. Instead of accompanying her all the way to Tara, he sends her on her way with a nearly dead horse, helplessly frail Melanie, her baby, and tearful Prissy, and with a passionate kiss as he goes off to fight. On her journey home, Scarlett finds Twelve Oaks burned, ruined and deserted. She is relieved to find Tara still standing but deserted by all except her parents, her sisters, and two servants: Mammy and Pork. Scarlett learns that her mother has just died of typhoid fever and her father's mind has begun to fail under the strain. With Tara pillaged by Union troops and the fields untended, Scarlett vows she will do anything for the survival of her family and herself.
Scarlett sets her family and servants to picking the cotton fields, facing many hardships along the way, including the killing of a Union deserter who attempts to rape her during a burglary. With the defeat of the Confederacy and war's end, Ashley returns, but finds he is of little help at Tara. When Scarlett begs him to run away with her, he confesses his desire for her and kisses her passionately, but says he cannot leave Melanie. Meanwhile, Scarlett's father dies after he is thrown from his horse in an attempt to chase away a scalawag from his property.
Scarlett realizes she cannot pay the rising taxes on Tara implemented by Reconstructionists, so pays a visit to Rhett in Atlanta. However, upon her visit, Rhett, now in jail, tells her his foreign bank accounts have been blocked, and that her attempt to get his money has been in vain. As Scarlett departs, she encounters her sister's fiancé, the middle-aged Frank Kennedy, who now owns a successful general store and lumber mill. Scarlett lies to Kennedy by saying Suellen got tired of waiting and married another beau, and after becoming Mrs. Frank Kennedy, Scarlett takes over his business and becomes wealthy. When Ashley is offered a job with a bank in the north, Scarlett uses emotional blackmail to persuade him to take over managing the mill.
Frank, Ashley, Rhett and several other accomplices make a night raid on a shanty town after Scarlett narrowly escapes an attempted gang rape while driving through it alone, resulting in Frank's death. With Frank's funeral barely over, Rhett visits Scarlett and proposes marriage, and she accepts. They have a daughter whom Rhett names Bonnie Blue, but Scarlett, still pining for Ashley and chagrined at the perceived ruin of her figure, lets Rhett know that she wants no more children and that they will no longer share a bed.
When visiting the mill one day, Scarlett and Ashley are spied in an embrace by two gossips, including Ashley's sister India, who dislikes Scarlett. They eagerly spread the rumor, and Scarlett's reputation is again sullied. Later that evening, Rhett, having heard the rumors, forces Scarlett to attend a birthday party for Ashley. Incapable of believing anything bad of her beloved sister-in-law, Melanie stands by Scarlett's side so that all know that she believes the gossip to be false. After returning home from the party, Scarlett finds Rhett downstairs drunk, and they argue. The argument leads to marital rape, which causes Rhett to return the following day to apologize for his behavior and offer a divorce, which Scarlett rejects saying it would be a disgrace.
Rhett takes Bonnie on an extended trip to London, but cuts the trip short after Bonnie suffers a terrible nightmare. On their return Scarlett is delighted to see him, but he rebuffs her attempts at reconciliation. She informs him that she is pregnant, but an argument ensues, and an enraged Scarlett lunges at Rhett resulting in her falling down the stairs and suffering a miscarriage. As Scarlett is recovering, Bonnie dies while attempting to jump a fence with her pony. Melanie visits their home to comfort them, but then collapses during a second pregnancy she was warned could kill her.
On her deathbed, Melanie asks Scarlett to look after Ashley for her, as Scarlett had looked after her for Ashley. With her dying breath, Melanie tells Scarlett to be kind to Rhett because he loves her. Outside, Ashley collapses in tears, forcing Scarlett to realize that Ashley only ever truly loved Melanie. Scarlett dashes home to find Rhett preparing to leave. She pleads with him, telling him she realizes now that she had loved him all along, and that she never really loved Ashley. However, he refuses, saying that with Bonnie's death went any chance of reconciliation. As Rhett is about to walk out the door, Scarlett begs him to stay but to no avail, and he walks away into the early morning fog leaving Scarlett weeping on the staircase and vowing to one day win back his love.