The action takes place in Salerno in the 18th century.
Baron Don Magnifico has two daughters, Clorinda and Tisbe, and a stepdaughter Angelina, nicknamed Cinderella. The stepfather has taken Cinderella's inheritance, and she is treated disdainfully in his household, as if a mere servant.
Act I
It's morning at Don Magnifico's house. While Clorinda and Tisbe preen in front of the mirror, admiring their elegance and beautiful attire, Cinderella, as always, busies herself with household chores, singing a melancholy song.
A knock at the door is heard. It's Alidoro, Prince Ramiro's tutor, disguised as a beggar, searching for a worthy bride for his pupil. When the beggar asks for alms, Clorinda and Tisbe respond rudely, while Cinderella offers him bread and coffee. Alidoro is deeply moved by the girl's kindness.
Suddenly, heralds arrive, announcing that Prince Ramiro intends to marry and will soon visit to invite Don Magnifico and his daughters to a ball where he will choose his future wife. Clorinda and Tisbe are thrilled and excited, each hoping to capture the prince's heart. Don Magnifico is also delighted: if Ramiro chooses one of his daughters, he can improve his faltering fortunes and even become a noble lord. The house bursts into a flurry of activity as Clorinda and Tisbe prepare for the ball.
Meanwhile, having learned from the faithful Alidoro that Don Magnifico's stepdaughter is a kind and lovely girl, Ramiro visits the baron's house, disguised as his own valet, Dandini. He decides to see for himself and test Cinderella's feelings. Cinderella and the prince have a heartfelt conversation. After hearing the girl's sorrowful story, Ramiro is enchanted by her charm, kindness, and nobility.
Following the disguised prince, Dandini appears at the doorstep in grand attire, posing as Ramiro. With feigned admiration he lavishes compliments and asks Don Magnifico and his daughters to attend the evening ball. Cinderella also longs to go to the ball and pleads with her stepfather to take her along. But Don Magnifico is adamant. He explains to those present that Cinderella is not his daughter but merely a simple servant and furthermore, she is of unknown descent. Cinderella insists on her rights. Then an enraged Don Magnifico begins to threaten her while simultaneously fabricating a "touching" story about the untimely demise of the third daughter.
As everyone leaves for the ball, Alidoro, comforting the distraught Cinderella, promises to take her to the palace and also take care of her attire and decorations.
Palace Garden. Dandini, still disguised as the prince, tells Ramiro about the vice, hopeless stupidity, and emptiness of Don Magnifico's two daughters and suggests abandoning the search for a bride. Meanwhile, the rival sisters appear. They try their best to charm the fake prince, flirting and playing up to him. But Dandini reasonably remarks that he cannot become the husband of both sisters at once, and suggests a choice: if one of them steps aside, then a worthy contender will be found for the other–the prince's servant, Ramiro. Both sisters indignantly reject the offer.
Meanwhile, the ball is in full swing. Suddenly, the arrival of an unknown lady, brought into the hall by Alidoro, is announced. It's the transformed Cinderella. Her elegant dress and jewels have made her unrecognizable and irresistibly beautiful. She immediately attracts a crowd of suitors. The beauty of the unfamiliar lady, strangely resembling Cinderella, sparks envy in Clorinda and Tisbe and fury in Don Magnifico. Yet the sisters do not despair, confident in their victory: the prince (disguised Dandini), though he noticed the mysterious lady, nonetheless continued to shower Clorinda and Tisbe with compliments on their beauty.
Guests are invited to the table. After dinner, a spectacle is to follow, then dancing and the choice of a bride.
Act II
Disguised as a servant, Ramiro watches Dandini and Cinderella from hiding. Dandini confesses his feelings to the girl. Cinderella, unaware that he is not the prince but merely the disguised valet, rejects his advances, for her heart belongs to another–the humble "prince's servant." An overjoyed Ramiro overhears everything. Now, Cinderella decides to test her beloved's feelings. She gives him a bracelet: if Ramiro loves Cinderella, he will find her by this bracelet. Without explaining further, the mysterious stranger leaves the palace.
Prince Ramiro orders everyone to search for her. The faithful Alidoro has already devised a trick that will lead to a "chance" encounter between the lovers: the prince's carriage will break down right outside Don Magnifico's house.
At this time, the baron, unaware of what has happened, persistently asks "the prince"– Dandini – to reveal his chosen bride. In response, he only laughs, revealing his true identity. A scandalous scene ensues. Realizing how he has been fooled, Don Magnifico flies into a rage. Dandini shows him the door.
Back at Don Magnifico's house. The enraged master and his distraught daughters return. Seeing Cinderella, sitting as always in a dark corner, they continue to speculate about the mysterious lady who appeared at the prince's ball.
A storm begins. Amid the noise of the rain and thunder, there's a knock at the door. Dandini enters. Now as a valet, he reports that the prince's carriage has broken down at the baron's house. Following Dandini, Ramiro appears in his true guise. Seeing the bracelet on Cinderella's wrist, he declares her his bride. The future spouses leave Don Magnifico's house.
At the palace, Ramiro's wedding plays out. Cinderella forgives her woeful relatives and rejoices that her suffering is behind her.