The original running time of "The Breakfast Club" was about two and a half hours. Thinking the film would not be a hit, Universal Pictures cut the running time down to 97 minutes. The studio then destroyed the negatives of the deleted scenes. Director John Hughes said in a "Premiere" magazine article that he has the only complete copy.

Director John Hughes wrote the script in two days, on July 4-5, 1982.

During the filming, Anthony Michael Hall and Molly Ringwald were dating.

John Hughes, the director, originally wanted John Cusak to play Judd Nelson's bad boy role. He finally gave in when he realized that John didn't look "tough enough".

At the beginning, there is a nameplate on an office desk that says R. Hashimoto. Richard Hashimoto is the production supervisor.

The woman who plays Brian's mom in the movie is Anthony Michael Hall's mom in real life.

When Andrew (Emilio Estevez)is telling his confession during the group therapy that scene took three days to film.

In it's short theatrical run The Breakfast Club took in $46 million, thrusting it into the top 20 highest-grossing films of 1985.

In the begining of the film they are showing shots of stuff around the school (with talking over top). One of the things it shows is a plaque with graduation photos. The student on this plaque with the phrase "Man of the Year" is the janitor, only a bit younger.

Brian's dad is played by director John Hughes.

Because of success people thought there would be a sequel, right? Wrong, director John Hughes refused to do another film for two reasons. One was because he and Judd Nelson had a terrible relationship, meaning they hated each other. Also because Molly Ringwald was trying to get out the role of the regular teen girl. Eventually she lost all ties with John Hughes when she started to pursue more adult roles.