Readers will be partying in their pyjamas at Hammicks in Bracknell, where there'll also be readings and fancy dress.
Meanwhile, Borders in Edinburgh is holding a treasure hunt. Wonder if they'll have to find a golden egg, like Harry in the Triwizard tournament?
And down in Cornwall, The Falmouth Bookseller promises to create a totally spooky atmosphere. It's throwing open its doors at midnight, when the shop will be lit by candles.
At Borders in Swansea, one lucky reader will get to open the padlock on the first crate of books to arrive there!
And a magician called Billy Bubbles will be entertaining the queue at The Dublin Bookshop in the Irish capital.
Bet Billy could teach Gilderoy Lockhart a trick or two!
Speed readers will be showing off their skills at Books, etc. in Manchester.
Hope they get plenty of rest before the event!
With OOTP being about 768 pages long, they could be there for some time!
CBBC Newsround will be giving you loads to read and do next week in the run-up, so make sure you check back!
And we'll be in the queues keeping you company at Waterstone's in London on Friday night - so watch out!