Below is every Amazon category keyword for both the US and UK store. Click a main category to expand and see all hidden subcategories for that section, or search a keyword to find all mentions of that keyword, both in the descriptions of the subcategory or the actual keywords used to put a book in an Amazon subcategory. We have romance, science fiction & fantasy, history and travel keywords + every other category! This is a complete list, so this is all Amazon category keywords in one place.
On Amazon, you select your main category, for example Historical. Then you click History below which will display a list of subcategory keywords, that is, keywords you include in your book’s keywords to get it listed in the subcategory. This process is automatic, you can check it worked by searching your book on Amazon once it’s published and scrolling down to see the listed subcategories. Note that category keywords with more than one word need their own keyword string, that is to say, you can slip in Aztec at any point in one of your seven allowed keyword strings, but bull run needs it’s own string.