In 1963 Baltimore, Maryland, overweight teenager Tracy Turnblad dreams of dancing on The Corny Collins Show, a local television program featuring a “council” of teenagers dancing to popular songs. One night, Tracy and her best friend, Penny Pingleton, sneak out to a record “hop” hosted by Corny Collins. Disappointed to find the event is segregated, they go in anyway and Tracy impresses the guest judge, Motormouth Maybelle, a local African American celebrity who co-hosts the The Corny Collins Show’s once-monthly “Negro Day.” Tracy and her dancing partner, Fender, win that night’s dance contest, narrowly beating council dancers Amber Von Tussle and her boyfriend, Link Larkin. Corny invites Tracy to audition for his show at the WZZT television studio the next day. There, Penny and an African American dancer, Nadine Carver, try out alongside Tracy, but Tracy outshines them during a mock interview and is elected to join the council, starting with that afternoon’s taping. A disapproving Amber teases Tracy about her weight, prompting Corny to suspend Amber for the day. Penny rushes to the Turnblad home to show Tracy’s parents, Edna and Wilbur, their daughter’s television debut. As Tracy dances before the cameras, a fan sends a telegram requesting that Tracy lead the “Lady’s Choice” dance. Meanwhile, at the Von Tussle home, the suspended Amber seethes in front of the television as Tracy selects Link for the slow dance. Although Edna Turnblad previously disapproved of Tracy’s hairstyle and incessant dancing, she now revels in her daughter’s newfound fame and takes her shopping at Hefty Hideaway, a store for plus-sized women. When the owner, Mr. Pinky, recognizes Tracy from the show, he offers to sponsor her with free clothes in exchange for modeling services. At school, Tracy is called to the principal’s office for violating the student hairstyle policy. The principal, Mr. Davidson, reprimands her for abusing hairspray and assigns her to a special education classroom. During physical education class, Amber refuses to talk to Link, angry that he danced with Tracy in her absence. When their group is pitted against Tracy in a game of dodgeball, Amber attacks Tracy with the ball, sending the heavyset girl to the ground. Link comes to Tracy’s aid as she regains consciousness and asks her to go steady with him. At the next taping of The Corny Collins Show, Tracy waves her promise ring before the cameras as she and Link dance together. Since Hefty Hideaway has become the show’s new sponsor, Tracy performs the extra task of modeling clothes during a paid advertising segment. Later, Tracy, Link, and Penny take the bus to an African American neighborhood to meet Tracy’s classmate, Seaweed, who happens to be the son of Motormouth Maybelle. The group arrives at Maybelle’s record store, where Seaweed’s younger sister, L’il Inez, tells Tracy she is her favorite dancer on the show. Penny’s overbearing mother, Prudence Pingleton, appears outside the store, having followed Penny there. Startled to see her daughter dancing with Seaweed, she busts into the store wielding a knife and smuggles Penny out against her will. On “Pre-teen Day” at the show, Penny is stopped at the door with Seaweed and L’il Inez, who are not allowed in because they are black. Penny leads her friends in an impromptu protest, chanting “Segregation never, integration now!” Inside, Corny tells the guard to let L'il Inez and her brother in, but the WZZT station manager, Arvin Hodgepile, refuses to desegregate. Hoping to deter their daughter from interracial dating, Penny’s parents hire a hypnotist and trap her in her bedroom. Meanwhile, Motormouth Maybelle organizes a protest at the opening of Tilted Acres, a segregated amusement park, as Corny Collins hosts a special taping. There, Amber introduces a new dance, “The Limbo Rock,” which requires dancers to bend backward and pass under a horizontal stick. Hoping to humiliate Tracy and garner more votes for the upcoming Miss Auto Show contest, Amber shows off her limbo skills while Tracy struggles to pass under the stick. Next, Tracy introduces a dance called “The Waddle,” but Amber steals the microphone to shout that Tracy has roaches in her hair. Protestors storm the park, inciting a riot that interrupts the dancers. Police arrest Tracy and beat Link to the ground. Later that night, Seaweed, who was also wounded during the riot, sneaks into Penny’s bedroom and they escape her screaming parents together. Corny Collins hosts another special taping at the Auto Show, but Tracy is stuck in reform school and unable to attend, and Link is confined to a wheelchair from being assaulted at Tilted Acres. Amber’s father, Franklin Von Tussle, builds a bomb and hides it in a large wig. His wife, Velma, dons the wig, with plans to throw the bomb if Tracy wins Miss Auto Show instead of Amber. Meanwhile, Motormouth Maybelle and L’il Inez handcuff themselves to the governor, refusing to leave until he frees Tracy. When Miss Auto Show is announced, Arvin Hodgepile reveals that although Tracy is the winner, she is ineligible and therefore Amber will be crowned. As the new Miss Auto Show, Amber introduces a dance called “The Roach” and dedicates it to Tracy. At the same time, the governor exonerates Tracy, and she dances her way to the Auto Show. Disregarding his boss’s mandate, Corny announces the show is now integrated, while Tracy changes into a Hefty Hideaway dress embroidered with roaches. She introduces a dance called “The Bug,” and Link stands up from his wheelchair to join her on the dance floor. As L’il Inez steals Amber’s crown, the bomb in Velma’s wig spontaneously detonates and the burning hairpiece lands on Amber’s head. Tracy finally receives her Miss Auto Show crown and cries out, “Let’s dance!”