Grease starts with the meeting of Sandy Olsson and Danny Zuko in the summer of 1958. Not long afterwards, they fall in love but Sandy worries that their relationship may not last long since summer’s end is fast approaching and her return to Australia is getting nearer by the day.
When classes resumes, Danny catches up with his gang, the T-Birds. Sandy unexpectedly enrolls in the same school as Danny’s where she meets the Pink Ladies led by Betty Rizzo, Danny’s ex-girlfriend.
When Sandy tells the girls about the boy he met that summer, Betty guesses that the boy must have been Danny. She sets up a surprise meeting between Sandy and Danny. However, Danny seems to have no regards for Sandy at all. One of the Pink Ladies invites Sandy to a slumber party so she can forget what happened between her and Danny. That night, Sandy hears the other girls talking behind her back.
Afterwards, Sandy begins to date the football player Tom Chisum which makes Danny jealous. Danny then seeks the help of Coach Calhoun so he can impress Sandy by playing some kind of a sport. After trying a lot of sports, Danny discovers his skills in track.
At the school dance, Danny gets partnered with another ex-girlfriend and they perform together for the national dance-off which is broadcasted on live TV. This greatly hurts Sandy and she goes home without Danny.
After a few days, Danny apologizes to Sandy. However, he hurts her again when he tries to make a pass at her. On the other hand, Betty Rizzo thinks that she’s pregnant but she gets insulted by her boyfriend when he tries to propose to her. To drive her boyfriend away, Betty tells him that the baby is not his and this starts a rumor about Betty. During this time, Sandy offers her support to Betty.
During a greaser race, Betty’s boyfriend asks Danny to be his substitute. Danny wins the race but he’s not completely happy because Sandy still does not want to talk to him.
Before the school year ends, Betty discovers that she’s not carrying a child and she reunites with her boyfriend. Danny on the other has become at athlete and Sandy appears wearing clothes fit for a bad girl. The movie ends with Danny and Sandy reuniting and proclaiming their love for each other.