This book explores the history of the Flat Earth idea and its advocates to determine what the political dimensions inherent to the idea of a Flat Earth are. For thousands of years, the belief that the Earth is flat has been a minority view expressed by those who are necessarily opposed to the worldviews of the hegemonic scientific, cultural, and political institutions of their time, across various contexts. In the late nineteenth and early twentieth centuries, the most prominent of those institutions were the British Empire and United States, which viewed science as integral to their nations and empire-building programs. As such, to those who opposed the projects of those countries—White and Black alike—the idea of a Flat Earth was a useful ideology that became combined with anti-colonial and anti-racist advocacy across the Atlantic. This is an approach that has been almost entirely absent from academic research not only of the Flat Earth movement, but of anti-colonialism as well.