For the scene where Judge Frollo sings "Hellfire" and sees Esmeralda dancing in the fire before him, the MPAA insisted that the Disney animators make Esmeralda's clothing more well-defined, as she seemed nude.
The song "Hellfire" is considered one of the darkest songs written for a Disney film, and was nearly cut from the film.
The opening musical number, "The Bells of Notre Dame," is, according to Alan Menken, the best opening number he has ever written.
According to the audio commentary on the DVD, the gargoyle that resembles a warthog (which can be seen during the climactic battle atop Notre Dame Cathedral) is actually not Pumbaa from The Lion King (1994) but the actual gargoyle that can be seen in that location on the real Notre Dame Cathedral in Paris.
While Quasimodo is singing "Out There," the camera pans over Paris and zooms in on a street. In this scene, Belle from Beauty and the Beast (1991) is seen walking and reading her book (walks out the bottom of the screen, to the right of the well), Pumbaa from The Lion King (1994) is being carried on a pole by two men (carried out of the bottom of the screen, but left of the well), and another man (in a gray-blue tunic) is shaking out the Carpet from Aladdin (1992).