One’s apprehension of the natural world, of ecosystems, and the species living therein, almost always takes shape in the contexts of (1) interspecific relational practices, (2) modalities and forms of naturalistic knowledge, and (3) institutionalized practices of encounter with nonhuman animals. The elaboration of particular cultural representations of nonhuman primates is no exception: it too largely depends on cultural variables. Scientific thought as disseminated for popular consumption, blockbuster films, and bourgeois entertainments, such as zoos and circuses, have contributed substantially to modern humans’ conceptions of primates, especially anthropomorphic apes. The ancient Roman world between the end of the first millennium BCE and the beginning of first millennium CE, however, was characterized by relational practices, cultural categories, and forms of scientific knowledge of nonhuman primates very different from those now operating in the Western imaginary. It is significant, for example, that the Romans most commonly interacted not with gorillas and chimpanzees, but with macaques and baboons. By investigating how nonhuman primates were integrated into Roman cultural encyclopedia, this article will center not on ape lore per se but instead upon the distinct cultural matrix within which primates were perceived, their behavior interpreted, and their relationship to humans understood.