Don Magnifico’s Mansion. As Angelina (known as “Cenerentola”) slaves away for Clorinda and Tisbe, her half-sisters, she sings a haunting refrain. An old beggar—really Alidoro, the Prince’s tutor in disguise—offends Clorinda and Tisbe by asking for charity. Cenerentola secretly gives him food, so he thanks her and promises her fate will soon change. A group of courtiers announces that at a ball that very evening, Prince Ramiro will choose a bride. Chaos erupts at the news.
The commotion awakens the Baron, Don Magnifico, interrupting a happy dream that he goes on to interpret (aria: “Miei rampolli femminini). His daughters tell him about the ball, and he urges them to don their finest clothes.
Prince Ramiro then enters, disguised as his own servant. When his dying father demanded Ramiro take a bride, the prince concealed his identity, hoping to find a woman who can love him for himself, not for his status. The “servant” meets the lovely serving-girl Cenerentola; they fall in love at first sight and sing the duet “Un soave non so che”.
Enter Dandini, really Ramiro’s servant but now masquerading as the Prince himself, to escort Don Magnifico’s daughters to the ball (aria: “Come un’ape”). Cenerentola asks permission to attend the ball, but Don Magnifico dismisses her. The company sets out, leaving Cenerentola behind. Alidoro returns and, in the aria “Là del ciel” tells Cenerentola that she will indeed go to the ball.
The Palace Garden. Don Magnifico finds himself appointed Royal Wine Steward. Meanwhile, Dandini, still pretending to be the Prince, tells Clorinda and Tisbe he can marry only one of them, and suggests the other marry his servant. The sisters are appalled by this proposal. A mysterious beauty, escorted by Alidoro, crashes the party. When she lifts her veil, the sisters feel that she looks too much like Cenerentola to be considered competition.
Inside the Palace. Don Magnifico and his daughters are discussing the mysterious lady at the ball and fantasizing about what life will be like when the Prince weds Clorinda or Tisbe. Meanwhile, Dandini (posing as the Prince) professes his love for Cenerentola, whereupon she confesses to loving his servant (really Ramiro). Ramiro is overjoyed, but mystified when she gives him one of two bracelets she wears—he is to search for a young woman wearing the other. If he still wants her when he finds out who she really is, she will marry him. She leaves him, and Ramiro immediately reassumes his true identity and, in the aria “Si, ritrovarla io giuro,” sets off to find his true love. Dandini takes great pleasure in telling Don Magnifico that neither of his daughters will wed the Prince—and that he himself is really just a servant.
Don Magnifico’s Mansion. Don Magnifico, Clorinda, and Tisbe return home, disappointed and angry. They find Cenerentola still doing chores. At the climax of a storm, Dandini and Prince Ramiro enter in search of shelter; their carriage has been blown over. Cenerentola is astonished to discover that her handsome servant is really the Prince; and he is flabbergasted to find the missing bracelet on her arm. All are surprised and bewildered, save only Dandini, who enjoys everyone else’s confusion to no end (sextet: “Questo è un nodo”). Ramiro vows he will wed Cenerentola and threatens to punish Magnifico, Clorinda, and Tisbe for their misdeeds.
Prince Ramiro’s Throne Room. In the aria “Nacqui all’affano” Cenerentola pardons her stepfather and his daughters and ascends the throne. Everyone hails her goodness and majesty.