J.K Rowling reveals on her official website the name of the final Harry Potter book. You got two options--1.) go to jkrowling.com and play a hangman game to figure it out for yourself or 2.)Using your mouse, hover {re: lay your cursor} over her image to see the name. A little window would appear over the picture to tell you the name of the new/final Harry Potter book. I don't want to spoil it for the Harry Potter fans out there.