Barbie stars as Genevieve, a princess with eleven sisters: Ashlyn, Blair, Courtney, Delia, Edeline, Fallon, Hadley, Isla, Janessa, Kathleen and Lacey. Each princess is beautiful and different, but the twelve sisters have one thing in common: they all love to dance. They live in a castle with their widowed father, King Randolph. Randolph loves his daughters deeply, but at times can't understand them and feels that they should act more like "proper" princesses. The girls' adventurous and free-spirited natures are viewed as "unladylike" and "unproper" by other members of the royal society and often leads them to make rude comments about the princesses. This both disheartens and hurts Randolph. Believing his daughters need a woman's touch, the king summons his cousin, Duchess Rowena, to the castle to help raise them. But, Rowena has her own plans, which includes getting rid of Randolph and his daughters so she can take over the kingdom. Sensing trouble, Genevieve and her sisters try to reason with Randolph, but due to Rowena's interference, the king doesn't believe them and says they must listen to his cousin. Attempting to break the girls' spirits, Rowena makes the princesses' lives miserable by stripping the castle of everything they love and having them practice "proper" behavior, like fanning. She even banishes dancing from the castle. Sad with the changes, the princesses find comfort in their mother's favorite story, which tells of a magical kingdom where gold flowers grant wishes and a princess could dance at an enchanted pavilion for three nights. They later discover that the story is true. The gateway to this magic realm is a mosaic on their bedroom floor. The mosaic has twelve circular tiles, which have each princesses' favorite flower on one and Genevieve opens it by dancing in order from oldest to youngest. They enter the magical kingdom and end up dancing the night away. Lacey, the youngest, falls and scrapes her knee. Genevieve dabs water from a nearby fountain on the cut and it instantly heals. The next day, the girls are tired and the duchess finds their new dancing shoes worn through. Suspicious, Rowena believes that they were out dancing with princes. Meanwhile, the royal cobbler and Genevieve's love interest, Derek, comes to fix their shoes and sees that they are covered in gold dust. While together, Genevieve asks Derek to find out what Rowena's true intentions are. The duchess continues to deprive them of any enjoyment and prevents them from visiting or singing to their father, who has suddenly fallen ill. The doctor gives Rowena a tonic for Randolph, which she quickly disposes of, revealing that she is poisoning him. That night, Rowena has her footman, Desmond, stand guard outside the princesses' room to find out where they go. The sisters sneak back to the magic realm and dance well into the night again. Meanwhile, Derek discovers that Rowena is stealing heirlooms from the castle and dealing with an apothecary (presumably for the poison). He hurries back to warn Genevieve and her sisters. The next morning, the sisters are still exhausted and Rowena demands to know why. When she gangs up on Lacey, the girls tell her the truth, but she doesn't believe them and forces them into servitude. That night, she demands the truth again, but they tell her the same story. This makes Rowena even angrier and she locks them in their room, blaming them for Randolph's failing health. Hurt by her cruel words and due to a misinterpreted conversation between the king and Rowena, the girls can't help but feel that she's right and that their father would be better off without them. Heartbroken and not knowing what to do, the princesses return to the magical kingdom. A furious Rowena finds the sisters gone the next morning. That evening, Derek finally makes it back to the castle, but discovers that the princesses are missing. Determined to find Genevieve, he sneaks into their bedroom. Remembering Genevieve's dance pattern, Derek enters the magic realm and reports his findings to the girls. Unfortunately, Rowena learns how to enter the magic realm, due to her monkey, Brutus. Stealing some flowers, she quickly returns to the castle and has Desmond destroy the mosaic that forms the gateway, trapping the sisters and Derek in the magical kingdom. Thinking she has disposed of the princesses, Rowena then tricks the weak Randolph into making her acting queen until he recovers. Trapped in the magic realm, the girls and Derek try to find a way out. Genevieve eventually learns that it is only by dancing with Derek that she can open another entrance back to their world. As they dance, the couple and the rest of the princesses float up into the sky and return home. However, this new gateway leads to their mother's dance pavilion (which is identical to the pavilion in the magic realm), instead of their bedroom. Once back, the sisters and Derek discover that Rowena is now queen, new guards (hired by Rowena) have been ordered to capture any stray princesses, and their father is dying. Using their diverse talents, the princesses disable the guards and enter the castle to confront Rowena. Ignoring Genevieve's orders, Lacey enters the castle to help, but is seized by Desmond. Derek and Genevieve defeat the enchanted suits of armor that defend Rowena, but the duchess has the upper hand when Desmond drags in Lacey. Noting that Genevieve is the source of her sisters' resistance against her, Rowena uses the flowers she stole to wish for Genevieve to dance forever. But as the flower dust comes towards her, Genevieve produces her fan and blows it back at Rowena, who starts dancing instead. Desmond soon joins her while trying to help and the two villains dance their way out of the castle and the film. It is revealed that Lacey saved some water from the magical kingdom and using it, she heals the dying king. Randolph explains that Rowena was poisoning him and apologizes to his daughters for not believing them. He now truly understands them and realizes they will do great things and be wonderful princesses by just being themselves. The film ends with everything going back to normal as Genevieve and Derek celebrate their wedding.