- John Travolta and Olivia Newton-John both auditioned for other roles before being cast as Danny and Sandy. Travolta initially auditioned for the role of Kenickie, while Newton-John auditioned for the role of Rizzo.
- The famous line "Tell me about it, stud" was improvised by Travolta.
- The T-Birds were originally supposed to be a group of bikers, not greasers.
- The song "Summer Nights" was originally written for the Broadway musical "West Side Story."
- The drive-in theater scene was filmed at the Coronet Theater in Los Angeles, which is now the site of the ArcLight Hollywood.
- The "Greased Lightnin" car was a 1948 Ford De Luxe convertible that was customized for the film.
- The film's budget was only $6 million, making it one of the lowest-budgeted musicals ever made.
- Grease is the highest-grossing musical film of all time, having earned over $394 million worldwide.