After seeing the film JK Rowling said: "It went wonderfully. I am so pleased, everyone seems to love it."
Decorated like Hogwarts
The Odeon in Leicester Square, London was made to look just like Hogwarts with a massive banner for each of the four houses hanging from the front.
Another famous face was the Duchess of York, who took her two daughters Princesses Beatrice and Eugenie.
She said: "It is brilliant. I thoroughly enjoyed it and the girls loved it."