In Paris, France, gypsy puppeteer Clopin narrates the origin of the deformed bell-ringer Quasimodo, explaining that he was adopted by Judge Claude Frollo at the behest of the cathedral Archdeacon after he killed Quasimodo's mother. In the present, Quasimodo, encouraged by the cathedral's gargoyles, Victor, Hugo, and Laverne, ventures out into the city for the first time to attend the Festival of Fools. While at the festival, he meets gypsy dancer Esmeralda, who accidentally exposes him to the public.
After Esmeralda defends Quasimodo from public humiliation, Frollo, believing her to be a witch, orders her arrested. However, she and Quasimodo retreat into the cathedral. Phoebus, Frollo's captain of the guard, refuses to arrest her and confines her to the cathedral. Esmeralda follows Quasimodo into the bell-tower, where the two bond. Quasimodo helps Esmeralda escape the cathedral, and she gives him a pendant before leaving. Frollo, who has gained lustful feelings for Esmeralda, orders a city-wide manhunt for her upon learning of her escape. Phoebus defies Frollo's orders to murder an accused family, and escapes execution, but is wounded in the process. Esmeralda brings Phoebus to the cathedral, where Quasimodo learns the two have fallen in love.
Frollo learns that Quasimodo had aided in Esmeralda's escape and claims that he will attack the gypsy hideout. Quasimodo and Phoebus, using the pendant, arrive at the hideout, where Clopin orders them executed. However, Esmeralda's goat Djali alerts her in time and she arrives to stop the execution. Frollo, who had followed the two to the hideout, arrives with his army and captures the gypsies.
Frollo sentences Esmeralda to death when she rejects his advances. However, Quasimodo, encouraged by the gargoyles, manages to free himself from his bonds and rescues Esmeralda, taking her to the Cathedral. Phoebus rallies the citizens of Paris to battle Frollo's men. In the ensuing battle, Quasimodo and the gargoyles pour molten copper on the streets to prevent the army from entering the cathedral. However, Frollo manages to break in and he arrives at the bell-tower. Quasimodo and Esmeralda flee onto the balcony, pursued by Frollo. In the ensuing confrontation, Frollo admits to killing Quasimodo's mother. As he attempts to kill Esmeralda, he plummets off the balcony and perishes in the molten copper below. Quasimodo falls soon afterwards, but is rescued by Phoebus.
Quasimodo, accepting that Esmeralda and Phoebus are in love, gives the two his blessings. They leave the cathedral, where the citizens accept Quasimodo into society and hail him a hero.