Miraheze.org

A not-for-profit wiki farm which can be used to host any wiki of your choosing. A good alternative to Fandom.com/Wikia as Miraheze lacks Fandom’s bloated, advertising-heavy interface—it is in fact completely free of all advertising whatsoever.

Simple to use: just create an account, and then put in a request to create a new wiki at https://meta.miraheze.org/wiki/Special:RequestWiki in order to set up your very own 100% free wiki. Miraheze hosting uses MediaWiki software, enabling users to create Wikipedia-style wiki sites. It has a number of different tools for site configuration as well as numerous skins to customize your wiki’s appearance.