Whip It begins just moments before a beauty pageant in Bodeen, Texas, where one contestant is notably absent. Backstage, Bliss Cavendar (portrayed by Elliot Page), a 17-year-old misfit and rebel, regrets the blue hair dye she was dared to apply by her best friend, Pash (Alia Shawkat). As she frantically tries to remove the dye, she ends up debuting on stage with her vibrant blue locks, leading to her defeat in the pageant and disheartening her mother, Brooke (Marcia Gay Harden).
Both mother and daughter are upset after the pageant loss, prompting Brooke to take Bliss shopping in Austin. There, Bliss is captivated by the exuberance of three roller-derby girls who are handing out promotional flyers. Intrigued, she takes one and later convinces Pash to accompany her to an exhibition derby match. Despite the team’s loss at the exhibition, Bliss encounters the Hurl Scouts, led by Maggie Mayhem (Kristen Wiig) and coached by Razor McGee (Andrew Wilson). After declaring the Hurl Scouts her heroes, Maggie encourages her with a rallying cry: > "Put some skates on, be your own hero."
Determined to join the team, Bliss lies about her age and secretly tries out for the team, knowing her parents would disapprove. Razor recognizes her talent and welcomes her into the Hurl Scouts. Although her first game sees the team lose, Bliss finds solace at an after-party, where she shares a connection with Oliver (Landon Pigg), a charming 19-year-old musician who admires her taste in music. However, their burgeoning romance takes a tumble when Bliss faces off against Iron Maven (Juliette Lewis), the captain of the rival team, leading to an embarrassing encounter.
The excitement continues when Oliver takes Bliss to an arcade where they attempt to bond through fun games, and later find themselves sharing a special moment away from the rest of the world. The following night, the Hurl Scouts triumph over another opponent, with Oliver in attendance, and Bliss shines as their point scorer, earning the nickname Babe Ruthless.
As the season progresses, Bliss and Oliver grow closer, yet she is devastated when he announces a tour with his band. Meanwhile, her relationship with Maggie deepens as the team climbs the leader boards, but the strain between Bliss and her mother grows because of her choices. After a latter match, police raid the venue, and in the ensuing chaos, Iron Maven learns of Bliss's true age. Pash, caught under-aged with alcohol, is arrested, leaving Bliss to seek solace with Oliver in a secluded getaway that leads to them sharing an intimate night.
When Bliss returns home, she faces her furious parents who have been informed about her involvement in roller derby. An argument ensues between mother and daughter, where Bliss asserts her need for independence, rebelling against the expectations of a typical housewife lifestyle imposed by Brooke. As Iron Maven threatens to expose her age, Bliss feels the weight of her secret and confides in her team.
Despite initial shock, the Hurl Scouts embrace Bliss when she reveals her true age, gearing up for their final match. As Bliss grapples with her feelings for Oliver, she discovers a photo of him with another girl, leading to heartbreak. Nevertheless, she reconciles with her mother, agreeing to participate in the upcoming Blue Bonnet Pageant, only to later realize that it conflicts with the championship match.
In a twist of fate, Bliss's father (Daniel Stern) recognizes the passion his daughter has for roller derby and persuades Brooke to let her follow her dreams. Just before the championship, Oliver returns, but their reunion is fraught with misunderstandings that culminate in a breakup.
The final match is a nail-biter, with Babe Ruthless going head-to-head with Iron Maven amidst a tense atmosphere. Ultimately, the Holy Rollers narrowly defeat the Hurl Scouts. Though initially devastated, the scouts rally together, reclaiming their spirits with chants of "We're number two!" reflecting their resilience.
In the aftermath, Brooke finds Bliss's heartfelt speech for the pageant, where she names her mother as the person she admires most. Meanwhile, Pash receives acceptance into a college in New York, while Bliss chooses to channel her passion for derby, contemplating a move to Austin. The film concludes with Bliss seated on the diner rooftop, lost in reflection as she embraces the journey of self-discovery she has undertaken.
