This chapter reviews and synthesizes the literature pertaining to the supply of disinformation, misinformation, and fake news in three main sections. First, we define and draw boundaries between the concepts of disinformation, misinformation, and fake news. Next, we offer an extensive discussion of the supply of these concepts. Specifically, we discuss how different actor groups (i.e. political actors, media actors, and citizens) create and disseminate inaccurate information. Here, we focus on these actors’ motives and how the impact of falsehoods might differ when it is supplied by political actors, media actors, or citizens. In the third section, we explain how the supply of actual disinformation, misinformation, and fake news is accompanied by a second mechanism, i.e. the perceived supply of falsehood, referring to growing beliefs that perfectly factual information is incorrect. We connect this to the ubiquitous debate about the prevalence of mis- and disinformation in many democracies, and specifically, to the weaponization of the term “fake news” by politicians to systematically discredit public trust in news media. We conclude by emphasizing the difficulties research faces in investigating the supply of disinformation, misinformation, and fake news and suggesting several avenues for future research on this crucial matter.