John Hughes almost fired Judd Nelson because of his negative attitude towards Molly Ringwald off camera. Paul Gleason convinced Hughes that Nelson was a great actor and was merely trying to stay in character.

The scene in which all characters sit in a circle on the floor in the library and tell stories about why they were in detention was not scripted. John Hughes told them all to ad-lib.

At the time of shooting, Molly Ringwald and Anthony Michael Hall were the only Breakfast Club members of high school age, both being 16. Emilio Estevez and Ally Sheedy both were 22, and Judd Nelson was 25.

It was originally suggested that there would be several sequels to The Breakfast Club (1985), occurring every ten years, in which “The Breakfast Club” would get back together.