Trivia: S.E. Hinton, the author of the book "The Outsiders," has a cameo in the scene where Johnny is in the hospital after the fire and is lying on his stomach. She's the nurse tending to Dally - the one who says "what did you do with your gown?"
Trivia: When Dally, Ponyboy and Johnny are in the car in the Dairy Queen parking lot, a little girl comes up to them and asks for some change. That is a young Sofia Coppola, daughter of Francis Ford Coppola, who is now also a notable movie director.
When Pony Boy, Dally and Johnny are pulling up to the burning church, just before the first one jumps out of the car if you look through the windshield you can see the water truck that's going to put out the fire after they shoot the scene.