This page includes a list of the 25 best-selling books of all-time as well as the 25 best-selling book series of all-time. Best-selling books are ranked by number of copies sold, not my personal ratings.
Also, it is worth noting that some religious and political books such as The Bible, Quran, and Quotations from Chairman Mao are believed to have more than a billion copies each in existence. However, sales numbers for these books are nearly impossible to track because many are given away by churches or governments. Additionally, these books have often been printed by a wide range of publishers over centuries, many of them unreported. For these reasons, major religious and political texts are not listed here, but we can all agree that they are among the top selling books of all-time.