The Duke of Mantua surveys his court to choose a woman with whom to pass the night and selects the Countess Ceprano. She is flattered but nervous; her husband is present. This leads to an impasse. Marullo enters with news for his fellow courtiers that Rigoletto, the jester, has a mistress in town. The Duke then discusses his dilemma with Rigoletto, who suggests the following alternatives for Ceprano: prison, exile, or beheading. Ceprano and the courtiers are outraged and swear vengeance on Rigoletto. Monterone, an old nobleman, comes to denounce the Duke and his dissolute court. With the Duke’s consent, Rigoletto mocks the old man and his dishonored daughter. Monterone curses both Rigoletto and the Duke for laughing at a father’s grief. Rigoletto suddenly fears for the safety of his own daughter, whom he has kept carefully hidden from the court.
Later that evening, Rigoletto is accosted by Sparafucile, who offers his services as a killer. Rigoletto spurns his offer and then reflects on their encounter. He sees Sparafucile as his alter ego: one kills with a sword, the other with words. Monterone’s curse continues to haunt him.
Rigoletto returns home and greets his daughter, Gilda, declaring that she means the world to him. She reciprocates his feelings but questions why he has kept her concealed. He fears the courtiers and warns the nurse to guard Gilda carefully. Hearing a noise in the street, he goes out to investigate. The Duke, disguised as a student, enters and is astonished to discover the girl he has seen in church is Rigoletto’s daughter. He and Gilda declare their love. Then, fearing Rigoletto’s return, he leaves. Left alone, Gilda rhapsodizes on the false name of the “student,” Gualtier Maldè, while outside the courtiers gather to kidnap the woman they believe to be Rigoletto’s mistress. To exact their revenge on the jester, they will present the girl to the Duke. Rigoletto returns to find the courtiers near his house, but they fool him into thinking they have come to abduct Countess Ceprano who lives next door. Too late, Rigoletto discovers the trick.
The Duke, unaware of what has occurred, laments the fact that when he returned to Gilda’s house he found it deserted. The courtiers describe how they kidnapped Rigoletto’s mistress, and the Duke leaves to find her. When Rigoletto enters, a remark from the page alerts him to Gilda’s whereabouts. He rages at his tormentors but is soon reduced to begging them for pity. When Gilda bursts onto the scene, Rigoletto orders the courtiers to leave him alone with his daughter. She explains how she met the Duke, whom she had taken to be a student, at church. Rigoletto comforts her. Monterone, on the way to his beheading, laments that no one has yet struck down his daughter’s seducer. Rigoletto promises to do so. Gilda begs mercy for the Duke.
Rigoletto has brought Gilda to Sparafucile’s inn to show her the real nature of the man she loves. The Duke, once again incognito, flirts with Sparafucile’s sister, Maddalena. Gilda laments his faithlessness, but still continues to love him. Rigoletto sends her home and hires Sparafucile to kill the Duke. Maddalena urges her brother to spare him, and he agrees, provided another victim can be found as a substitute so that he can keep his pact with Rigoletto. Gilda, unable to follow her father’s orders, returns and presents herself as the victim after overhearing the conversation. Rigoletto returns to collect his victim and is given a body. Hearing the Duke’s voice in the distance, he quickly uncovers the wraps and finds the dying Gilda. Monterone’s curse has been fulfilled.