Harry's right hand girl talks about her favourite lines in the film, her favourite scenes and her hopes for the sequel.
CBBC Newsround's Lizo Mzimba spoke to her before the first film was released in November 2001.
Click here to watch the interview or scroll down to read it
What did you do when you found out you got the part of Hermione?
I rang my best friend, just as I'd been told, literally minutes after I'd been told, I rung my friend and she answered and she said: "So have you got it?" And I said: "Yes." And she screamed, she literally just went arghhh - it was like five minutes, I had to hold the phone here, not to be able to break my ear and she was so excited she was almost more excited than me.
What were you most looking forward to about the filming?
I think the best thing which I was looking forward to seeing from the book was just the outlook from the whole of the school because it describes in the book coming over in a boat across the river to Hogwarts and just the first view - that took us ages, we had to keep going ahh, wow, ooh - a bit like watching fireworks going off, it was like ooh, eee, ahh, ooh.
What was your best scene?
My favourite scene was probably the most difficult scene which was really weird - it was the troll scene. I had to do lots and lots and lots and lots of stunts which I think is one of the reasons I enjoyed it but one of the reasons it was so hard as well.
They had six cubicles and they had to put a safety mat underneath it, so in the end I was climbing on to something - we actually measured it, 30 centimetres high, I had to climb on to six cubicles and I kept banging my head, I was darting under sinks to make sure the troll didn't hit me, I had to do loads of running through legs and scrambling around the place and the really annoying thing was that they haven't used all of the stunts which I did, which was really annoying - not good enough!
What was your fave line from the film?
I liked the line at the end where I said: "I'm going to bed before either of you come up with another clever idea to get us killed or worse expelled!"
And another one was where I said: "Honestly you're going to take someone's eye out!" Hermione always has some really snooty lines for Ron, I think Ron gets the worst of it really.
What do you think you'll enjoy the most about filming the second Potter adventure?
The thing I'm looking forward to most in the second film is probably how they're going to make me look like a cat, that'll be very interesting.