Nigeria is usually described as a deeply divided country whose ethnic and religious diversity, and the management thereof, has often posed significant difficulties. This chapter contributes to an understanding of the complex and contradictory roles of religious civil society in building peace in Nigeria. It draws on literature on the ambivalent roles of civil society and religion in peace-building to highlight the strategies, compromises, and processes of fostering peaceful relations between Muslims and Christians, especially since Nigeria’s return to civilian rule in 1999, and examines key constraints and obstacles related to context and political opportunity structure that hinder civil society from fulfilling these functions.