This chapter explores the religious influences on Nigeria, the spread and development of these religions, and their incorporation or imposition in various precolonial and colonial institutions. The topics explored throughout the chapter will lay the foundation for modern-day Nigeria’s religious make-up and sectarian conflict. There are two primary phenomena detailed in the chapter. The first is the efforts of colonial forces to implement a system of indirect rule, an essential component of which was the incorporation of pre-existing religious institutions into the colonial fold. The second was the desire of colonial and missionary forces to spread Christianity and Western culture to the various peoples of Nigeria. Both processes would promote Islam and Christianity at the expense of African traditional religions. However, Indigenous practices would vigorously resist, often infusing their beliefs into colonial institutions and various sects of Christianity.