The Breakfast Club is a 1985 American teen drama written and directed by John Hughes. The storyline follows five teenagers (each a member of a different high school clique) as they spend a Saturday in detention together and come to realize that they are all deeper than their respective stereotypes. The film has become a cult classic, a defining film of the 1980's, and has had a tremendous influence on many coming of age films since then. It was shot entirely in sequence. Shooting began on March 28, 1984, and ended in May 1984.

The plot follows five students at fictional Shermer High School in Shermer, Illinois as they report for Saturday detention on March 24, 1984. While not complete strangers, the five teenagers are each from a different clique or social group.

The five students, who seem to have nothing in common at first, come together at the high school library, where they are harangued and ordered not to speak or move from their seats by the antagonistic principal, Richard Vernon (Paul Gleason). They are to remain for a period of eight hours and fifty-four minutes (from 7:06 A.M. to 4 P.M., the only indication of time being on a clock that is 20 minutes fast). He assigns a 1,000 word essay (in which each student must write about who he or she thinks he or she is) and then leaves them mostly unsupervised, returning only occasionally to check on them. Bender, who has a particularly negative relationship with Mr. Vernon, disregards the rules and riles the other students; mocking Brian and Andrew, and sexually harassing Claire. Allison remains oddly quiet except for the occasional random outburst.

The students pass the hours in a variety of ways. Gradually they open up to each other and reveal their inner secrets (for example, Allison is a compulsive liar, Bender comes from an abusive household and Brian and Claire are ashamed of their virginity). They also discover that they all have strained relationships with their parents and are afraid of making the same mistakes as the adults around them. However, despite these developing friendships the students are afraid that once the detention is over, they will return to their very different cliques and never speak to each other again.

At the request and consensus of the students, Brian is asked to write the essay Mr. Vernon assigned earlier (the subject of which was to be a synopsis by each student detailing "who you think you are"), which challenges Mr. Vernon and his preconceived judgments about all of them. Brian does so, but instead of writing about the actual topic he writes a very motivating letter that is in essence, the main point of the story. He signs the essay as "The Breakfast Club" and leaves it at the table for Mr. Vernon to read when they leave. There are two versions of this letter, one read at the beginning and one at the end, which are slightly different; illustrating the change in the students' judgments of one another and their realization that they truly have things in common.

The beginning letter is as follows:

The end letter is as follows:

Each of the film's young stars became part of the Brat Pack (whose other members include Rob Lowe, Andrew McCarthy and Demi Moore), a group of actors who found fame at the same time and were sometimes cast in films together. John Hughes appeared in an uncredited role as Brian's father. Of the entire cast, only Hall and Ringwald were actually high school age upon the film's release; Nelson was 25, while Sheedy and Estevez were both 22 years old.

Emilio Estevez was originally cast to play John Bender, but because Hughes couldn't find anyone to play Andrew Clark, Estevez agreed to take the role. Nicolas Cage was being considered for the role of John Bender. Bender was the last role to be cast, and it was between John Cusack and Judd Nelson. Hughes eventually cast Cusack to play John Bender, but decided to replace him with Nelson before shooting began because Cusack didn't look threatening enough for the role. Molly Ringwald also wanted to play Allison Reynolds, but Ally Sheedy had already been promised the part. Rick Moranis was originally cast as the janitor; he left due to creative differences and was replaced by John Kapelos.

Judd Nelson's performance was influenced by his method-style technique of staying in character off set. He was accused of bullying Molly Ringwald due to his insistence on remaining in character when the camera was not rolling. This behavior nearly forced Hughes to fire Nelson, but Nelson was defended by Paul Gleason, his on-screen nemesis, who stated that Nelson was just trying to stay in character and did not mean any wrong by it.