Inside Chicagoland

At the very beginning of the movie, Brian's voiceover spells out the setting for us: "Saturday... March 24, 1984. Shermer High School, Shermer, Illinois." So we know where we are, and when. When the movie was released, 1984 would've been roughly the present day (the movie came out in 1985). Fortunately, the world hadn't become a totalitarian dictatorship by that time—excepting the USSR and China. So put that in your curvy old English pipe, Orwell!

The Breakfast Club is set in Shermer—a suburb of Chicago and the center of John Hughes's fictional universe. Practically all of Hughes's movies are set there or involve characters from Shermer, from Sixteen Candles to Planes, Trains, and Automobiles to Home Alone.

Hughes grew up in Northbrook, the basis for Shermer: a family-friendly, upper-middle-class to upper-class Chicago suburb. But Hughes wasn't as rich as many of his ultra-wealthy classmates. The Hughes family was middle-class, and Hughes's dad sold roofing tiles.

So, Hughes felt a little discontent with this atmosphere, which seeps into The Breakfast Club: You can see it in the verbal conflict between rich kid Claire and impoverished Bender (also, Brian doesn't seem rich either—he's more middle-class, probably similar to Hughes). The wealthy side of Shermer becomes clearer in Home Alone—where Kevin McCallister's family takes off for a Christmas vacation in France. (Source)

Shermer lies at the center of America. It's an ultra-typical kind of place for the Midwest, although it seems pretty ethnically homogenous (everyone in The Breakfast Club is white). In the movie, we really get to see just one location within Shermer—Shermer High School. It doesn't look too bad, really, for a school. The library is massive, at any rate (probably because the actual school library was too small for the filmmakers' purposes, so they built a giant library set in the school gym).

The Breakfast Club was filmed at North High School in Des Plaines, Illinois—a location spiritually and physically pretty close to where Shermer would actually have been. It was right in John Hughes's native stomping grounds near Chicago. (Source)

So Mystically Normal, It Could be Anywhere

Since there's not that much to do in a library aside from read—or, if you're Bender, desecrate books—these kids are forced to either interact with each other or stay quiet. At first, they stay quiet—but Bender's antics force them into a confrontation. The relatively confined space they find themselves in helps spur this action.

We also get to see other parts of the school, like the hallways, a closet, a room with confidential student files, and the football field (at the very end). It's all deeply typical—the kind of high school anyone could imagine themselves in.

That's part of the charm of The Breakfast Club: It's shooting for that intensely relatable sense of normalcy and trying to access everyone's high school experience. Ultimately, The Breakfast Club's setting feels universal and yet totally '80s. It's timeless and timely all at once.