Don Magnifico's vain daughters, Clorinda and Tisbe, are primping. Their stepsister, Cinderella (whose real name is Angelina) sings a song about a long-ago king who chose a good and innocent bride. When a beggar (actually Prince Ramiro’s tutor, Alidoro) appears, the stepsisters chase him away but Cinderella makes him welcome. There is an announcement that Prince Ramiro, in search of the most beautiful girl in the land to be his bride, will soon pay a visit. The sisters order Cinderella to get them ready to receive him, and their squabbling wakes Don Magnifico. In so doing, they have interrupted a dream, which he interprets to mean that good fortune will soon visit the family. His premonition seems vindicated when he learns of the Prince’s visit. Magnifico exhorts the girls to capture the Prince's heart to save the family fortunes.
Disguised as his own valet, the Prince arrives alone so that he can observe the women of the household incognito. He meets Cinderella and is enchanted. Dandini (the real valet) arrives disguised as the Prince, enjoying his new status, and invites the fawning sisters to a ball. Cinderella begs her stepfather to take her too but Magnifico brutally orders her to stay at home, to Ramiro's shock. Alidoro, now in his true identity, questions Don Magnifico about his third daughter. Magnifico tells Alidoro that she is dead. After everyone except Cinderella has left, Alidoro reveals his identity and transforms her for the ball. At the palace, Magnifico discovers the wine cellar. Clorinda and Tisbe continue chasing Dandini, but scornfully reject Ramiro. All are enchanted by the arrival of a mysterious, veiled lady. When she unmasks they are struck by her uncanny resemblance to Cinderella.
Ramiro is smitten with the newly arrived guest. He overhears Cinderella refusing Dandini’s attentions because she loves his ‘valet’ and delightedly steps forth to declare himself. Cinderella gives him one of a pair of matching bracelets, saying he will find her wearing its twin. Then she rushes away. After she leaves, Ramiro relinquishes his false identity and vows to find her. Dandini, now reduced to his former servant status, smashes Magnifico’s dreams of grandeur and turns him out of the palace.
Returning home, Magnifico and the sisters resume their cruel treatment of Cinderella as a storm hits.