1. The original choices for the role of Sandy were Susan Dey and Deborah Raffin.
2. Stockard Channing wasn’t the first choice for the role of Rizzo.
3. Carrie Fisher and Lorna Luft were also considered for the role of Rizzo.
Luft went on to play Paulette in Grease 2.
11. The “hickeys from Kenickie” were real hickeys that Jeff Conaway insisted planting on Stockard Channing.
13. Director Randal Kleiser shot a scene portraying a gritty and heated fight between Rizzo and Kenickie that would have given some background to their milkshake incident in the diner scene.
It was cut because it didn’t match the lighter tone of the rest of the film.
19. The “You’re The One That I Want” scene was shot with a traveling carnival.
Kleiser later decided he needed more close-up shots from the scene, but the carnival was long gone by then, so the set designers had to build replica backgrounds for the scene.