The outbreaks of major pandemics have historically been associated with the proliferation of conspiracy theories. This article explores what role conspiratorial narratives have played in the development of different “imagined communities” in the premodern, modern, and contemporary worlds. I argue that premodern conspiratorial narratives were mostly focused on eschatological and theological images, aiming to blame and delegitimise the religious Other. In these imaginary plots, spread of disease was interpreted as an attack on one’s religious beliefs. The prevalence of religious conspiracies helped reinforce religiously based, yet temporary, “imagined communities.” With the rise of nation-states and the decline of empires and patrimonial kingdoms, the periodic outbursts of epidemics gradually attained more nationalist interpretations. Hence in the modern era, pandemics often triggered the growth of nationalist conspiracies. In these narratives the threatening Other was usually nationalised, and even traditional religious groups became reinterpreted as a threat to one’s national security. In recent times, new technologies and modes of communication have created space for the emergence of global conspiracy theories. The onset of Covid-19 has been associated with the dramatic expansion of such conspiracies. Some scholars have interpreted this as a reliable sign that nation-states and nationalisms have lost their dominance. However, this article shows that many global conspiracies in fact reinforce nationalist ideas and practices and, in this process, foster the perpetuation of national imagined communities.