In Paris during the late Middle Ages, Louis XI, the King of France, and his Chief Justice of Paris, Jean Frollo, visit a printing shop. Frollo is determined to do everything in his power to protect Paris from anything he sees as evil, including the printing press and gypsies, who at the time are persecuted and prohibited from entering Paris without a permit. That day is Paris' annual celebration, the Feast of Fools. Pierre Gringoire, a poor street poet, does a play in front of an audience until it is interrupted by Clopin, the King of the Beggars. Esmeralda, a young gypsy girl, is seen dancing in front of an audience of people. Quasimodo, the hunchback and bell ringer of Notre Dame Cathedral, is crowned the King of Fools until Frollo catches up to him and takes him back to the church.
While trying to find Louis to speak to him, Esmeralda is caught by a guard for entering Paris without a permit and is being chased after by a couple of soldiers until she seeks safety in Notre Dame, in which the Archbishop of Paris (Frollo's brother Claude) protects her. She prays to the Virgin Mary to help her fellow gypsies only to be confronted by Frollo, who accuses her of being a heathen. Afterwards, she asks Louis to help her people, to which he agrees. Frollo then takes her up to the bell tower where they encounter Quasimodo, of whom she is frightened. As she runs away from the hunchback, Frollo commands Quasimodo to chase after her and kidnap her. Gringoire witnesses all this, and calls out to Captain Phoebus and his guards, who capture Quasimodo just in time and saves Esmeralda. She starts falling in love with Phoebus, but later marries and saves Gringoire from being hanged in the the Court of Miracles. Shortly after, Frollo orders the guards to arrest and round up the gypsy girls to make an inspection in an attempt to find Esmeralda.
Quasimodo is sentenced to be lashed in the square and publicly humiliated afterwards. He then asks the Parisian townspeople for water. Frollo, seeing this, realizes that he can't stop the sentence in time because it already happened, and abandons Quasimodo instead of helping him. However, Esmeralda arrives and gives Quasimodo water, and this awakens the hunchback's love for her.
Later that night, Esmeralda is invited by the nobles to their party where she dances with a black goat named Aristotle, but shortly after Frollo shows up to the party and he confesses to Esmeralda his lust for her in a hiding place. Afterwards, she and Phoebus go to a garden where they share a moment between each other, which ends up in Frollo killing Phoebus out of jealousy, and Esmeralda being wrongly accused of his death. Frollo arrives at Notre Dame where he confesses the crime to his brother, and, knowing that the Archbishop refuses to help him because he is the murderer, intends to sentence Esmeralda to death for it (which he does), saying that she has "bewitched" him.
Gringoire tries to get Esmeralda free by writing an appeal and claims Esmeralda's innocence during her trial, but fails. After Esmeralda is forced under torture to confess Phoebus's murder, Louis shows up to the courtroom and attempts to help Esmeralda by offering her a trial by ordeal, telling her to choose one of two daggers: her own dagger or Louis's dagger. When Esmeralda chose her dagger, Frollo sentences her to be hanged in the gallows. As Esmeralda is being taken in front of Notre Dame to do public penance, the Archbishop claims her innocence and does not allow her to do penance; however, Frollo still orders Esmeralda to be hanged in the gallows. Just as she is about to be hanged, though, Quasimodo saves her by taking her to the cathedral.
When Gringoire and Clopin realize that the nobles are planning to revoke Notre Dame's right of sanctuary, they both try different methods in order to save Esmeralda from hanging: Gringoire writes a pamphlet, and Clopin leads the beggars to storm the cathedral. At the Palace of Justice, Louis realizes that the pamphlet is creating public opinion, which can influence kings to make decisions. The Archbishop arrives to inform Louis of Notre Dame's attack and that Esmeralda is innocent, Louis demands to know who the real murderer is, to which Frollo confesses his crime to Louis and walks away, leaving Louis shocked. Louis orders Olivier to arrest Frollo and then talks to Gringoire after reading his pamphlet.
Meanwhile, Quasimodo and the guards of Paris fight off Clopin and the beggars. Afterwards, he sees Frollo in the bell tower seeking to harm Esmeralda, and when he comes up, Frollo tries to stop him. Frollo then attempts to kill Quasimodo with a dagger, but Quasimodo, realizing Frollo's evil nature, stops him and in defense for himself and Esmeralda he throws Frollo off the cathedral top, sending him down to his death. Later that morning, Esmeralda is pardoned by the King and freed from hanging due to the success of Gringoire's pamphlet. Her Gypsy people are also finally freed. Then, she comes to truly love Gringoire and leaves with him and a huge cheering crowd out of the public square. Quasimodo sees all this from high on the cathedral and says sadly to a gargoyle, "Why was I not made of stone, like thee?".