At a lavish party hosted by the Duke of Mantua, the insatiable womanizer tells his courtier, Borsa, about his obsession with a girl he has seen in church. He knows where she lives and means to have her—and whichever other women he fancies in the meantime (aria: “Questa o quella”). He flirts with Countess Ceprano in front of her furious husband. The situation escalates when the court jester, Rigoletto, taunts the Count. Rigoletto flaunts the fact that he enjoys the Duke’s protection. When Marullo arrives at the party with gossip that Rigoletto has a mistress, Count Ceprano and the other courtiers devise a scheme to strike back at Rigoletto, whom they all despise.
Monterone’s arrival brings the party to a stop. He is the outraged father of a young woman the Duke has used and shamed. Rigoletto cruelly derides Monterone’s grief. As the Duke coolly orders Monterone’s arrest, the incensed father damns both the Duke and Rigoletto with a curse.
Unnerved by the curse, Rigoletto meets the hired killer Sparafucile on his way home. The assassin offers the jester his services. Alone, Rigoletto (recitative: “Pari siamo”) compares himself with the assassin: instead of a knife, he kills with his cruel taunts. Full of self-loathing, he rails against mankind, nature, his deformity, and his fate—to be a clown, forced to smile and ridicule people for a living.
Rigoletto arrives home to his daughter Gilda, whom he keeps locked away, hidden from the world. Ignorant of her own background and even her father’s name, she asks many questions. Rigoletto demurs, only telling her that she is all he has in the world since the death of her mother. He confines Gilda to the house and orders the housekeeper, Giovanna, to keep a strict watch on her.
Gilda tells Giovanna that she has fallen for a young man who has been following her home from church. Chasing his prey, the Duke turns up at Rigoletto’s house in disguise. He bribes Giovanna, then seduces Gilda (duet: “È il sol dell’anima”), telling her he is a student named Gualtier Maldè. Hearing footsteps, Giovanna warns him to leave. The Duke reluctantly departs. Enraptured, Gilda sighs the name of her first love as she goes to sleep (aria: “Caro nome”).
Marullo, Ceprano, Borsa, and other courtiers arrive to abduct Rigoletto’s “mistress.” When Rigoletto unexpectedly returns, Marullo sells him the story that the courtiers are going to kidnap Countess Ceprano, who lives nearby. They fool Rigoletto into helping them break into his own house, where they capture Gilda. Upon discovering the trick and his daughter’s abduction, Rigoletto remembers Monterone’s curse.
The next morning, the Duke is ranting that Gilda wasn’t there when he returned to Rigoletto’s house. The courtiers tell him they’ve abducted Rigoletto’s “mistress” and brought her to the palace. Guessing that they mean Gilda, he rushes to where the girl is captive. Rigoletto, searching for Gilda, confronts the courtiers (aria: “Cortigiani”). He reveals that the girl is his daughter, begging them for compassion. The courtiers remain unmoved. Gilda emerges, distraught from her ordeal. She tries to tell her father what has happened. They are interrupted by Monterone who, on the way to his execution, pardons the Duke and takes back his curse. In response, Rigoletto swears vengeance on the Duke, both for himself and for Monterone. Gilda pleads for her father to have mercy on the Duke.
In a tavern, the Duke, in disguise, is in high spirits (aria: “La donna è mobile”). Rigoletto forces Gilda to observe him with Maddalena, Sparafucile’s sister (quartet: “Bella figlia dell’amore”). He tells his heartbroken daughter to flee the city and promises to join her the next morning.
As a storm begins to rage, Rigoletto and Sparafucile settle on a price to kill the Duke. Rigoletto tells Sparafucile he will return for the body at midnight. Sparafucile takes the Duke to a room where the Duke waits for Maddalena. She, too, is now infatuated with the Duke, and begs her brother to spare him. She asks Sparafucile to kill Rigoletto when he returns.
Drawn back to the tavern, Gilda overhears Sparafucile agree to murder someone else and substitute that corpse for the Duke’s. Gilda rashly decides to sacrifice her own life to save the Duke. She knocks on the door and meets her fate. Rigoletto returns for the Duke’s body. As he prepares to throw the sack containing the corpse into the river, he hears the Duke’s voice in the distance. Rigoletto rips open the sack to find Gilda, who dies in his arms. Monterone’s curse has been fulfilled.