It turns out that books with key in the title are way more common than you think. Here are 50+ good books with key in the title, including both fiction and non-fiction. It's safe to say that most of these titles are books about keys, but the core commonality between these books is that they have the word key in the title.Books with key in the title include 5 Keys to Sensible Weight Loss by Paul Reisser, The Glass Key by Dashiell Hammett, and Sarah's Key by Tatiana De Rosnay. If you have a favorite key book, vote it up below, or add it to the list if it's not already here. It doesn't matter if it's science fiction, fantasy, romance, or non-fiction - if the book has key in the name, it belongs on this list.