There is no one most sold non-fiction book. This is because non-fiction books are often niche books that appeal to a specific audience. For example, a book about history or a science book will not sell as well as a novel or a book about a popular topic such as relationships. However, there are some non-fiction books that have been very popular and have sold millions of copies. These include books such as "The Hunger Games" by Suzanne Collins, "The Catcher in the Rye" by J.D. Salinger, and "To Kill a Mockingbird" by Harper Lee.
