In the run-down castle of Don Magnifico, his daughters Clorinda and Tisbe are in the middle of one of their usual arguments. Their stepsister Angelina, called Cenerentola, who serves as the family maid, sings her favorite song about a king who married a common girl. There is a knock on the door and Alidoro, tutor to the prince Don Ramiro, enters, dressed as a beggar. The stepsisters want to send him away, but Cenerentola gives him bread and coffee. Courtiers arrive to announce that Ramiro will soon pay a visit: he is looking for the most beautiful girl in the land and will hold a ball to choose his bride. Magnifico hopes that it will be one of the stepsisters: marriage to a wealthy man is the only way to save the family fortune. When the room is empty, Ramiro enters alone, dressed in his servantʼs clothes so he can freely observe the prospective brides. Alidoro has told him that there is a girl in the house worthy to be a princess, and Ramiro is determined to find out who she is. Cenerentola returns and is startled by the presence of a stranger. The two are immediately attracted to each other. He asks her who she is, and Cenerentola stammers a confused explanation, then runs away. Finally, the “prince” arrives—in fact Ramiroʼs valet, Dandini, in disguise. To Ramiroʼs amusement, Magnifico, Clorinda, and Tisbe fall over themselves flattering this prince, who invites them to the ball. Cenerentola asks to be taken along but Magnifico refuses. Ramiro notes how badly Cenerentola is treated. Alidoro reenters with information that there is a third daughter in the house but Magnifico claims she has died. Left alone with Cenerentola, Alidoro tells her he will take her to the ball and explains that God will reward her good heart. At Ramiroʼs country house, Dandini shares with the prince his negative opinion of the two sisters. But both men are confused, since Alidoro has spoken well of one of Magnificoʼs daughters. Clorinda and Tisbe appear again, having followed Dandini who still poses as the prince. When he offers Ramiro as a husband to the sister the prince does not marry, they are outraged at the idea of marrying a servant. Alidoro enters with a beautiful unknown lady who strangely resembles Cenerentola. Unable to make sense of the situation, they all sit down to supper, feeling as if they are in a dream.