Act I | Angelina, also called Cinderella, sings a pathetic little song about a king who finds a wife among the commoners.  She serves as maid to her stepfather, Don Magnifico, Baron of Montefiascone, and his two daughters, Clorinda and Tisbe, in his run-down mansion. A beggar arrives at the door, who is really Prince Ramiro’s tutor, Alidoro, in disguise. Cinderella pities him and offers him refreshment.  When the stepsisters see her generosity, they quarrel with Cinderella but are interrupted by Prince Ramiro’s followers who announce the Prince’s arrival to search for the most beautiful girl in the land to be his bride. Awakened by the commotion, Don Magnifico emerges in a nightcap and dressing gown, and scolds his daughters for interrupting his dream about a donkey with wings. When Clorinda and Tisbe tell him about the Prince's visit, he urges the girls to save the family fortunes by snaring Ramiro as a husband. They all retire to prepare themselves for the royal arrival, and Prince Ramiro—disguised as his own valet, Dandini—enters alone, wanting to see the women of the household without their knowing who he is. Cinderella is startled by the handsome stranger. He asks her who she is, and Cinderella tells him of her life of drudgery, and then excuses herself to respond to her stepsisters' shouts for her service.

While Don Magnifico gathers Clorinda and Tisbe, Dandini enters disguised as the prince, and declares his quest for the fairest in the kingdom. He invites the sisters to the ball at his palace. Don Magnifico also prepares to leave, arguing with Cinderella, who does not want to be left behind. Ramiro notes how badly Cinderella is treated. Alidoro, still dressed as the beggar who came earlier, reads from a census list and asks for the third daughter who resides in the house. Don Magnifico says she is dead and leaves with Dandini. Alidoro casts off his rags, and tells Cinderella she is to accompany him to the ball. He identifies himself as a member of the court and presents her with two crystal bracelets as a symbol of “her goodness; pure and true.”

In a room at the palace, Don Magnifico is hailed as the prince's chief wine counselor. No one, he decrees, shall mix a drop of water with any wine for the next fifteen years. Looking forward to the feast, he and his attendants leave. Dandini reports to the prince that he finds the two sisters appalling, confusing Ramiro, who has heard Alidoro speak well of one of Don Magnifico's daughters. Clorinda and Tisbe rejoin Dandini; when he offers Ramiro as an escort for one of them, they become offended. Alidoro announces the arrival of an unknown guest. Ramiro recognizes something in her voice. When she lifts her veil, Prince Ramiro, Dandini, as well as the sisters, sense something familiar about her appearance. Their confusion is shared by Don Magnifico, who comes to announce supper and notices the newcomer's resemblance to Cinderella.

Act II | Don Magnifico stews over the newest threat to his daughters' chances with the Prince.  He leaves with his daughters just as Ramiro enters, smitten with the mystery guest who resembles the girl he met that morning. He hides as Dandini courts Cinderella. She declines his pursuits stating she is in love with someone else—his valet. At her declaration of love, Prince Ramiro comes out of hiding and pronounces his love for her. To test his sincerity, she gives him one of the matching bracelets, saying that if he really cares for her, he will find her.

Don Magnifico demands Dandini choose his bride among his daughters. Dandini confesses he is simply the Prince’s valet. Don Magnifico becomes enraged, and Dandini orders him out of the palace.

Cinderella is back in her rags when Don Magnifico and the sisters return home, all in a foul mood. As a thunderstorm rages outside, Dandini appears at the door, saying the prince seeks shelter, since his carriage has overturned outside. Cinderella realizes the valet is really Prince Ramiro, and he recognizes her and her bracelet. Prince Ramiro chastises Cinderella’s family, but she asks him to show mercy. Cinderella leaves with the prince.

In the palace throne room, Don Magnifico tries reconciling with the newly created princess. She asks only to be acknowledged as his daughter. All is forgiven among the family as she declares that her days of sitting by the fire are over.