The Church of Nigeria is the Anglican church in Nigeria. It is the second-largest province in the Anglican Communion, as measured by baptised membership, after the Church of England. In 2016 it stated that its membership was “over 18 million", out of a total Nigerian population of 190 million. It is "effectively the largest province in the Communion." As measured by active membership, the Church of Nigeria has nearly 2 million active baptised members. According to a study published by Cambridge University Press in the Journal of Anglican Studies, there are between 4.94 and 11.74 million Anglicans in Nigeria. The Church of Nigeria is the largest Anglican province on the continent of Africa, accounting for 41.7% of Anglicans in Sub-Saharan Africa, and is "probably the first [largest within the Anglican Communion] in terms of active members."

Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea to the south in the Atlantic Ocean. It covers an area of 923,769 square kilometres (356,669 sq mi), and with a population of over 230 million, it is the most populous country in Africa, and the world's sixth-most populous country. Nigeria borders Niger in the north, Chad in the northeast, Cameroon in the east, and Benin in the west. Nigeria is a federal republic comprising 36 states and the Federal Capital Territory, where the capital, Abuja, is located. The largest city in Nigeria is Lagos, one of the largest metropolitan areas in the world and the largest in Africa.