At a lavish party hosted by the philandering Duke of Mantua, he tells his courtier, Borsa, about his obsession with a girl he has seen in church. He flirts with Countess Ceprano in front of her furious husband. The situation escalates when the court jester, Rigoletto, taunts the Count. 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.
He is the outraged father of a young woman the Duke has used and shamed. Unnerved by the curse, Rigoletto meets Sparafucile, an assassin for hire, on his way home. The assassin offers the jester his services. 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. 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. Hearing footsteps, Giovanna warns him to leave. The Duke reluctantly departs. They fool Rigoletto into helping them break into his own house, where they capture Gilda.
Guessing that they mean Gilda, he rushes to where the girl is captive. 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. 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.
