The Duke of Mantua is hosting a ball, aided by his jester Rigoletto. Together they mock Count Ceprano, whose wife the Duke has openly courted. Ceprano vows revenge. Count Monterone arrives. He denounces the Duke for having seduced his daughter, and puts a curse on both the Duke and Rigoletto. The jester returns home to his daughter Gilda, whom no one knows about. Rigoletto lets her out of the house only to go to church. However, at church Gilda has caught the attention of the Duke. The Duke woos her as a poor student, even after he has discovered her identity. The Duke and Gilda are interrupted by Ceprano and his men, intent on abducting what they think is Rigoletto's mistress – in fact, Gilda. Rigoletto joins them, believing they are going to kidnap Countess Ceprano, but, wearing a blindfold, unwittingly lets them take his own daughter from his own house. The Duke thinks he has lost Gilda, but then learns she (though the courtiers still believe it is Rigoletto’s mistress) is being held in his palace.
Rigoletto returns to the court, distraught. No one helps him. However, Gilda appears and her father is outraged. When he sees Count Monterone being led away to prison, Rigoletto vows vengeance against his master, despite Gilda’s protestations of love for the Duke. Rigoletto takes Gilda to an inn run by the killer-for-hire Sparafucile to watch the Duke womanising. The Duke makes advances towards Maddalena, Sparafucile’s sister. Gilda is shocked and Rigoletto sends her away. Rigoletto pays Sparafucile to kill the Duke, but Maddalena, learning of the plan, pleads with her brother to save the Duke. A compromise is agreed. The first person to come to the inn door before midnight will be murdered. Gilda has overheard the conversation. She will sacrifice herself for the Duke. Rigoletto returns to collect the body, but is puzzled to hear the Duke singing in the distance. He discovers his daughter, dead. Count Monterone’s curse has been fulfilled.