Debate has been going on about the plot of the new book after JK Rowling admitted two characters will be killed and some think it could actually be Harry Potter himself.
Book chain Waterstone's children's book buyer, Sam Harrison, said the news had been greeted with "huge excitement" among Harry Potter fans.
The last book, Harry Potter and the Half-Blood Prince, broke British records by selling just over two million copies on its first day of release and total worldwide sales of all Harry Potter titles is now more than 52 million.
