We can also tell you that Tom, the innkeeper at the Leaky Cauldron, will be played by bald comedian Jim Tavare.
Tavare knows Tom looks like a "wizened, toothless walnut," so we're guessing he's not too vain!
Sirius still not cast
But there's no firm news yet about who will play Sirius Black.
Actor Gary Oldman has been linked to the role.
But sources on the film told us that, as of Wednesday afternoon, no one had signed on the dotted line to play Sirius.
Filming will begin on Azkaban in the next couple of months, so we'll let you know as soon as we do!