Corrected entry: When Mia and her mom and her grandmother are talking in their kitchen after Mia has found out about her royalty, she says something like "What's next? Are you going to tell me I have a twin who's a duchess?" Then her grandmother responds with "No, but you have a cousin who is a Contessa, fondly known as Bartholomew. But, actually we call him Pookie." A Contessa is Italian for a countess-a female count, so what she should have said is "No but you have a cousin who is a count...."
Corrected entry: When Lana, Anna and Fontana are in their cheerleader outfits and performing "Grove Lions", look at the back and you can see a girl who is obviously not used to cheerleading. When the rest of the girls twirl round she can't twirl, and at the end when they all say "Go Lions!" her back has turned and she has to turn round to join in with the rest of the group.
Corrected entry: Ignoring the common mistakes in geography for any movie filmed in San Francisco, there is a shot of a helicopter flying away from the beach party with an island and Palm Tree in the ocean in the back ground. There is nowhere along the coast of San Francisco where an island is visible. (01:17:00)
Corrected entry: At the end of the ball when everyone is dancing, you see the band in the background playing their instruments. Even though they're going along with the pop music being played, they're playing instruments that don't exist in the song.
Corrected entry: When Mia finds out that she is a princess and asks her mother why she never told her, her mother says that Mia's father and herself were planning on telling her when she turned 18. But later in the film, when it's Mia's 16th Birthday, Mia receives a diary from her father and a letter he wrote before he died. In the letter he tells her that today, her 16th Birthday, is an important day where she has a big decision to make(whether to become a the princess or not). But weren't they planning on telling her when she turned 18?
Corrected entry: I guess only somebody with curly hair would notice this, but in the beginning of the movie before her makeover, the character Amelia has what appears to be naturally bushy, frizzy, curly hair. Later in the movie, when she is racing to get to the ball in time, she's sitting in the pouring rain soaked from head to toe. If your naturally curly hair is straightened, it will get curly again when it's wet. Her hair is still straight.