The home of Don Magnifico, Baron of Montefiascone
Angelina (Cenerentola) sings a song about a king who, in searching for a bride, chose a girl for her goodness over her wealth.
Alidoro, the court philosopher, who is disguised as a beggar, knocks at the door. Cenerentola takes pity on him, although her half-sisters, Clorinda and Tisbe, spurn him. Courtiers soon arrive to announce that, on that very evening, at a ball, the Prince will choose a bride. Clorinda and Tisbe argue over who should relate the news to their father and the commotion wakes Don Magnifico from a magnificent dream. His daughters tell him about the ball and then run off to make themselves beautiful.
Don Ramiro, the prince, enters disguised as his valet, Dandini. Upon seeing Cenerentola, it is love at first sight. When he questions her about her identity, she answers evasively. Dandini arrives, disguised as the Prince, and Don Magnifico, Clorinda and Tisbe do all they can to make him happy. When Cenerentola asks Don Magnifico's permission to attend the ball, he refuses, treating her as nothing more than a servant. The company sets out, leaving Cenerentola behind. Alidoro tells Cenerentola that she will indeed go to the ball but she must not reveal her identity to anyone.
Don Ramiro's palace
Dandini tells the prince of the effects of their disguises on the baron's two daughters but Ramiro has already judged Clorinda and Tisbe to be undeserving of his love. When Cenerentola arrives at the ball, everyone is won over by her great beauty, stirring up her step-sisters' jealousy. Although they notice a resemblance, neither Clorinda nor Tisbe can accept that this woman could possibly be Cenerentola.