Ella and her parents live a humble but happy life until her mother falls ill. Ella promises to follow her mother's dying wish: to have courage and be kind. Years later, Ella's father marries Lady Tremaine, who has two unpleasant daughters, Drisella and Anastasia. Ella's father leaves on business, and Lady Tremaine reveals her cruel and jealous nature, pushing Ella to give up her bedroom to the stepsisters and move to the attic. When Ella's father unexpectedly dies, Lady Tremaine dismisses the household staff to save money and forces all their chores on Ella. Seeing Ella's face covered in cinders after sleeping by the fireplace, her step-family mockingly dubs her "Cinderella".
Distraught over her stepfamily's judgement towards her, Ella rides off into the woods where she happens to encounter Kit, the crown prince, hunting. He hides that he is a prince and instead introduces himself as a palace apprentice. Ella and Kit take a liking to each other, but they part without him learning her name. The King discovers he has little time left to live, and urges Kit to take a princess as his bride at the upcoming royal ball. Kit persuades his father to also invite every eligible maiden in the kingdom, hoping to see Ella again.
On the night of the ball, Ella tries to join her step-family, wearing her mother’s old gown that she has refashioned, but Lady Tremaine and Drisella tear it to shreds in jealousy and leave without her. Ella runs into the garden in tears and meets an old beggar woman, who reveals herself to be Ella's Fairy Godmother. She magically transforms a pumpkin into a carriage, mice into horses, lizards into footmen, and a goose into the coachman. She then transforms Ella's ripped gown into a beautiful ballgown, complete with a pair of glass slippers. As Ella departs, the Fairy Godmother warns her the spell will end at the last stroke of midnight, and casts a final spell to prevent Ella's stepfamily from recognizing her.
At the ball, the entire court is entranced by Ella. She dances with Kit, much to the chagrin of the Grand Duke who has already promised Kit to Princess Chelina of Zaragoza, which Lady Tremaine overhears. Though surprised at Kit's true identity, the Prince bonds with Ella, but before she can tell Kit her name, the clock chimes midnight and she flees the palace, losing one of her slippers. Pursued by the Grand Duke and his men, Ella manages to escape home before the final stroke of midnight; the spell dissipates and everything reverts back to its true form. Ella hides the remaining slipper under her bedroom floorboards.
The King dies, but not before giving his son permission to marry Ella. Now the new king, Kit issues a royal proclamation professing his love for the “mystery princess” and requests she present herself. Ella hurries to retrieve the glass slipper to prove her identity, however, having deduced that Ella is the mystery princess, Lady Tremaine informs Ella of her attempt to blackmail to make her head of the royal household and find respectable husbands for her stepsisters, in exchange for giving Ella's hand in marriage to Kit. Ella refuses, and Lady Tremaine smashes the slipper and locks Ella in the attic. She brings the shattered remains of the slipper to the Grand Duke, who agrees to make her a countess and secure marriages for her daughters in exchange for keeping Ella hidden.
The Grand Duke and the Captain of the guards lead the search for the mystery princess by trying the slipper on every woman in the kingdom, but it refuses to fit anyone. At Ella's house, the shoe fits neither stepsister; the company prepares to depart, but hear Ella singing Lavender's Blue. The Grand Duke urges them to leave, but Kit, who has secretly accompanied them, commands the Captain to investigate. The slipper fits Ella, and she and Kit promise to accept one another for who they truly are. As they leave, Ella forgives her stepmother. Soon after, Lady Tremaine, her daughters, and the Grand Duke are banished from the kingdom, never to return.
Ella and Kit marry and become the kingdom's most beloved monarchs, ruling with the same courage and kindness that Ella had promised her mother, and live happily ever after.