In 1912 New Orleans, a woman is reading the story “The Frog Prince” to her young daughter, Tiana (voiced by Elizabeth Dampier), and her daughter’s friend, Charlotte La Bouff (voiced by Breanna Brooks). Charlotte finds the story romantic, while Tiana proclaims she would never kiss a frog. Tiana enjoys a happy, but simple life with her mom (voiced by talk show host Oprah Winfrey) and her dad (voiced by Terrence Howard). The years pass and a 19-year old Tiana (voiced by Anika Noni Rose) is now a waitress and has become a beautiful young woman. She works two jobs so she can save enough money to start her own restaurant, fulfilling her late father’s dream.
Elsewhere, Prince Naveen (voiced by Bruno Campos) of Maldonia arrives in New Orleans determined to better his financial situation. After being cut off by his parents, Naveen is forced to marry a rich southern belle. It soon becomes obvious that Tiana’s best friend and the rich sugar baron’s daughter, Charlotte La Bouff (voiced by Jennifer Cody), is the perfect candidate. Eli “Big Daddy” La Bouff (voiced by John Goodman), Charlotte’s father, is hosting a masquerade ball in Naveen’s honor. Charlotte hires Tiana to make beignets for the ball, giving her just the right amount of money needed to finally buy an old sugar mill that she wants to convert into her restaurant.
Meanwhile, Naveen and his valet, Lawrence (voiced by Peter Bartlett), run into the shady Facilier (voiced by Keith David), a voodoo doctor. Inviting them into his emporium, Facilier convinces the pair he can make their dreams come true. However, neither man gets what he’s expecting; Naveen becomes a frog, while Lawrence is given a voodoo charm that makes him look like Naveen. Facilier intends for Lawrence to marry Charlotte, after which he will kill Big Daddy La Bouff and claim his fortune.
At the ball, Charlotte flirts with “Naveen” as Tiana learns she may lose the mill to a higher bidder. Adding insult to injury, her costume is accidentally ruined. Charlotte gives Tiana a princess costume and tiara so she can rejoin the ball. After Charlotte returns to the party, Tiana makes a wish on a Star, only to find a frog sitting next to her. The frog is Naveen, who asks Tiana (believing that she is a real princess) to kiss him and break Facilier’s curse. Tiana agrees, in exchange for the money needed to outbid the other buyer. However, instead of Naveen turning into a human, Tiana is turned into a frog herself.