The article focuses on flat earthism, one of the most well-known contemporary conspiracy theories in popular culture. According to proponents of this theory, which has found a growing international following in recent years, political institutions such as the U.S. government and scientific institutions such as NASA would operate to deceive humanity about the real shape of our planet and the universe in which we live. In countering the data acquired by modern science and common sense knowledge, flat earthism stands as a heterodox theory and a radical critique of the authority of socially legitimized epistemic institutions. This article consists of two parts. The first part will offer a genealogical reconstruction of the flat-earth conspiracy, tracing its history from the 19th century to the exponents of the current movement. The second part will delve into the discourse of the proponents of flat earthism with specific reference to the Italian context, through documentary analysis of recent publications and online material available on YouTube and Telegram, which constitute some of the main channels for the discussion and dissemination of flat earthism in Italy today. On the basis of the data collected and analyzed, it will be shown how flat earthism represents a paradigmatic case of superconspiracy, that is, of a far-reaching theory capable of linking and including within itself a set of other, more circumscribed theories. To this end, flat earthism elaborates on a discourse that ambivalently combines two registers, scientific and religious language, proposing itself as a dissident narrative that if on the one hand rejects the knowledge of institutionalized and organized science and religion, on the other hand accredits an alternative and anti-intellectualist path of knowledge, accessible to the “common man” that aims to create a space of autonomy and opposition to the processes of secularization and globalization in which the flat earthers see the project of building a dystopian New World Order.