Popular support is important to the emergence and survival of democracy. In this paper, we study how church-state relations in former British Africa shaped long-run support for democracy. We argue that shared national identity was the basis for incentive alignment, facilitating cooperation over educational policy between church and state and engendering long-run support for democracy. Employing geospatial analyses of historical mission data and contemporary social survey data from 19 former British African colonies, we find that areas with missions originating from Britain exhibit better educational outcomes and greater support for democracy than areas that had non-British missions. Furthermore, areas with British Protestant missions show greater support for democracy than British Catholic missions, suggesting that Protestantism supplements the benefits of shared nationhood between mission and state. Our findings add nuance to scholarship on the colonial origins of democracy by highlighting the interdependent legacies of church and state.