Andrew McCarthy's character has several witty lines that are lifted directly from Ian Shoales, a fictional pop-culture critic created by Merle Kessler of the Duck's Breath Mystery Theater. Ian Shoales appeared on NPR's "All Things Considered," as well as MTV's "The Cutting Edge" (1983). The "St. Elmo's Fire" credits give "special thanks" the Duck's Breath Mystery Theater.
The characters all attended Georgetown University together. After reading the script, Georgetown University administrators refused to allow producers to film on campus, so the on-campus scenes were filmed at the University of Maryland. No Georgetown University buildings appear in the film.
St. Elmo's Bar is based on The Tombs, a popular watering hole with Georgetown University students. For exterior shots, a full street set built at Universal Studios in L.A was used.
The "booga-booga" cheer that the friends do when they are celebrating or just in a good mood was not originally in the script. In a later interview, Rob Lowe stated that the cheer came out of observing fans whispering about the stars of the movie and then laughing. The cheer itself makes fun of what these whispered conversations sounded like from a few feet away.
Demi Moore had a drug problem, much like her character when she was cast in the film. One day, director Joel Schumacher actually demanded that she leave the set because she was really high. Moore actually had to go through rehab and promise to stay clean in order to play a character with a drug problem.
One of the bars was used in the film was torn down in Washington, DC with several of the cast members in attendance.
Singer John Parr, who co-wrote and sung the title song "St. Elmo's Fire" for the soundtrack, explained during a speech at the Childrens choice awards in Sheffield that he was "not particularly thrilled" to be working on the film and that, motivation for the song actually came from a young man who had recently become paralyzed. He said that "the wheels" of the Man in Motion referenced in the lyrics was popularly thought to mean the wheels of Demi Moore's jeep, but actually refers instead to those of a wheelchair.
The street that the St. Elmo bar is on is in the Universal back lot with several fill in buildings in between sets. About two to three buildings to the left is the Hill Valley Clock Tower from Back to the Future (1985).