In 1482 Paris, Clopin, a gypsy puppeteer, narrates the origin of the titular hunchback. A group of gypsies sneak illegally into Paris, but are ambushed by Judge Claude Frollo, the minister of justice, and his guards. A gypsy woman in the group attempts to flee with her deformed baby, but Frollo pursues and kills her outside Notre Dame. He tries to kill the baby as well, saying that it is an “unholy demon” from Hell, but is confronted by the cathedral’s archdeacon, who accuses Frollo of murdering an innocent woman. To atone for his sin, Frollo agrees to raise the deformed child in Notre Dame as his son, naming him Quasimodo.
Twenty years later, Quasimodo develops into a kind yet isolated young man who dreams of seeing life outside the bell tower, but is told by Frollo that he is a monster and would be rejected by the outside world. Three living stone gargoyles serve as Quasimodo’s only company and friends. The gargoyles encourage Quasimodo to attend the annually-held Festival of Fools. He goes but is stopped by Frollo who says he should stay inside the bell tower and forgives Quasimodo. Ignoring Frollo’s advisories, Quasimodo attends the festival and he is celebrated for his bizarre appearance, only to be humiliated by the crowd after Frollo’s men start a riot. Frollo refuses to help Quasimodo, but Esmeralda, a kind gypsy, intervenes and frees the hunchback, and uses a magic trick to evade arrest. Frollo confronts Quasimodo and sends him back inside the cathedral.
Esmeralda follows Quasimodo to find him, only to be followed by Captain Phoebus of Frollo’s guard as well. Phoebus does not approve of Frollo’s methods and refuses to arrest her for alleged witchcraft inside Notre Dame and has her confined to the cathedral. Esmeralda, encouraged by the Archdeacon, offers a prayer to God to help her and the outcast. Esmeralda finds and befriends Quasimodo, who helps her escape Notre Dame out of gratitude for defending him. Esmeralda entrusts Quasimodo with a pendant containing a map to the gypsies’ hideout, the Court of Miracles. Frollo soon develops lustful feelings for Esmeralda and upon realizing them, Frollo begs the Virgin Mary (referring to her as Maria) to save him from her “spell” to avoid eternal damnation, after learning of her escape, engages a city-wide manhunt for her involving burns down numerous houses which he suspects would shelter gypsies in his way. The gargoyles try to make him feel better about himself. Phoebus, now realizing Frollo’s evil reputation, defies him after being ordered to burn down the home of an innocent family and is ordered to be executed, but flees. Phoebus is briefly injured and falls into a river, but Esmeralda rescues him and takes him to Notre Dame for refuge.
Frollo returns to Notre Dame later that night and realizing that Quasimodo helped Esmeralda escape, bluffs that he knows about the Court of Miracles and that he intends to attack at dawn. Using the map Esmeralda gave Quasimodo, he and Phoebus find the court to warn the gypsies, only for Frollo to follow them and capture all the gypsies present. Frollo prepares to burn Esmeralda at the stake after refusing his advances, but Quasimodo, chained up inside the Bell Tower, manages to break free and rescue her in time, bringing her to the cathedral. Phoebus then frees himself and the gypsies and rallies the citizens of Paris against Frollo and his men, who attempt to break into the cathedral. Quasimodo and the gargoyles pour molten copper onto the streets to ensure no one enters, but Frollo successfully breaks in himself and pursues Quasimodo and Esmeralda to the balcony where both he and Quasimodo fall over the edge. Frollo falls to his death in the molten copper, while Quasimodo is caught in time by Phoebus on a lower floor. Afterward, Quasimodo is encouraged by both Phoebus and Esmeralda to leave the cathedral into the outside world, where the citizens hail him as a hero and accept him into society.