Wikidata is a repository of structured data about all kinds of knowledge in the world. Since 2012, it has grown to be a gigantic knowledge base that can be edited by everyone and used freely to answer all your questions. We will talk about how Wikidata is structured, how to query it with SPARQL, and what kind of applications people have already built with it. We will also introduce you to Wikibase, the MediaWiki extension that powers Wikidata and lets you create your own instance of a Linked Open Data knowledge base.