Using a quasi-survey method and desk analysis approach, this chapter in the first section examines the diversity of religion in Nigeria by gathering data through a semi-structured questionnaire, which was randomly distributed in twelve major cities across Nigeria (six from the North [Kano, Kaduna, Abuja, Jos, Mubi and Jalingo] and six from the South [Oshogbo, Ibadan, Effurun, Benin City, Enugu and Owerri]). The interview/questionnaire focused on the identification of worship centres such as ATR shrines, Church buildings and Mosques in the randomly selected cities. It aims to show the diversity of religions in Nigeria by focusing on the presence of worship centres in randomly chosen streets in selected cities in the North and South. The result shows that both Christianity and Islam are strongly present in Nigeria besides ATR. Although this is a common knowledge in Nigeria, this chapter corroborates such knowledge. Moreover, using the desk analysis approach, the second section of this chapter also examines ethnic diversity in Nigeria by extracting information from records of statutory establishments such as National Population Commission (NPC), National Bureau of Statistics and other sources where Nigeria’s religious and ethnic statistics were archived. The information generated from the above sources were used to form a simple statistical representations and interpretations.