My dissertation evaluates entrepreneurial religion at Rome during what appears to be its greatest efflorescence, from approximately the mid-first century BCE through the height of imperial expansion. The exchange of religious expertise for financial and symbolic capital constitutes a discrete phenomenon that warrants careful theorization. Entrepreneurs did not enjoy legitimacy through inherited channels and licit mechanisms, but purveyed novel or otherwise inaccessible practices to consumers with finite reasons for seeking them out. Though many of these practices comprise categories like magic, astrology, and mystery cults, I offer an analysis of specialist activity that cuts across its assorted permutations. Unlike publications that resort to dualisms between practical and “spiritual” aspects of religion to explain their appeal, my approach situates the practices and strategies of entrepreneurs, as well as the conditions for their enthusiastic reception, in the city’s material circumstances during this period.