During the summer of 1958, Danny Zuko (John Travolta) and Sandy Olsson (Olivia Newton-John) share a passionate romance at the beach. As summer concludes, they reluctantly bid farewell, with Sandy returning to Australia. However, fate intervenes when Sandy's family decides to stay in the U.S., leading her to enroll at Rydell High School, where she unexpectedly crosses paths with Danny, who is also a student there, along with her new friend Frenchy (Didi Conn), a member of the Pink Ladies.
Amid the school dynamics, Danny is the charismatic leader of the boys' gang known as The T-Birds. His buddy Kenickie, the gang's second-in-command, attempts to coax Danny into sharing tales of his summer escapades, while the Pink Ladies encourage Sandy to reveal her version of events. Through the lively number "Summer Nights," both Danny and Sandy embellish their summer stories, yet they remain oblivious to each other's presence in the same school.
The Pink Ladies aim to reunite this estranged couple, but Danny struggles to balance his desire for coolness with his feelings for Sandy. When his demeanor pushes Sandy to tears, he momentarily regrets his actions but quickly resumes his tough-guy facade and returns to his friends. Frustrated with Sandy's straight-laced attitude, Rizzo (Stockard Channing) mocks her, making it clear that she is tired of Sandy's prim demeanor, especially when Sandy struggles with a cigarette and is horrified by the thought of getting her ears pierced. In an attempt to toughen up Sandy, Frenchy brings her to the bathroom, but when Sandy gets queasy at the sight of blood, she barely holds it together.
Meanwhile, Rizzo's budding romance with Kenickie heats up, but the scene takes a turn when Leo, the leader of the rival gang The Scorpions, interrupts them, leading to a series of car-related mishaps. Back at the T-Birds' garage, Danny, with some convincing from his friends, sees potential in a dilapidated car they are fixing. Later, he meets Sandy again at the Frosty Palace, where he tries to mend their relationship, only to become jealous when he sees her with jock Tom Chisum (Lorenzo Lamas). To impress Sandy, he attempts to integrate into the jock crowd but fails misserably.
As the school dance approaches, excitement is in the air! Danny and Sandy try to share a special moment amidst the chaos of jealous exes and rival gangs. Danny's complications multiply when Rizzo, upset with Kenickie's behavior, flirts with Leo to provoke him, while Sandy grapples with her feelings when she sees Danny win a dance contest with Cha Cha, leaving her feeling overshadowed.
Later, while trying to strengthen their connection, Danny and Sandy’s relationship takes another hit during a drive-in movie date, leading Sandy to complain about Danny's disrespectful behavior when his attempts to get closer to her go awry. This results in Sandy storming out, leaving Danny devastated.
As tensions rise with rival gangs, a face-off begins with a race between Danny and Leo, which becomes a thrilling spectacle. With Sandy watching anxiously, Danny manages to win the race, reigniting hope in their relationship. The school carnival sets the stage for the final act of transformation when Danny dons a letterman sweater, embracing his sporty side, while Sandy, undergoing a dramatic makeover, steps out in a striking new outfit, complete with a leather jacket and bold attitude.
In an electrifying reunion, they burst into the vibrant song, "You're the One That I Want," heralding their love. The finale brings Kenickie and Rizzo together after Rizzo clears the air about her previous fears, culminating in a Joyous celebration as the entire cast sings "We Go Together." With a thrilling conclusion, Danny and Sandy soar off in his car, disappearing into the horizon, marking the end of their high school adventures.
