Christianity was introduced at Benin in the fifteenth century by Portuguese Roman Catholic priests who accompanied traders and officials to the West African coast. Several churches were built to serve the Portuguese community and a small number of African converts. When direct Portuguese contacts in the region were withdrawn, however, the influence of the Catholic missionaries waned and by the eighteenth century had disappeared.

Although churchmen in Britain had been influential in the drive to abolish the slave trade, significant missionary activity was renewed only in the 1840s and was confined for some time to the area between Lagos and Ibadan. The first missions there were opened by the Church of England's Church Missionary Society (CMS). They were followed by other Protestant denominations from Britain, Canada, and the United States and in the 1860s by Roman Catholic religious orders. Protestant missionaries tended to divide the country into spheres of activity to avoid competition with each other, and Catholic missions similarly avoided duplication of effort among the several religious orders working there. Catholic missionaries were particularly active among the Igbo, the CMS among the Yoruba.

The CMS initially promoted Africans to responsible positions in the mission field, an outstanding example being the appointment of Samuel Adjai Crowther as the first Anglican bishop of the Niger. Crowther, a liberated Yoruba slave, had been educated in Sierra Leone and in Britain, where he was ordained before returning to his homeland with the first group of missionaries sent there by the CMS. This was part of a conscious "native church" policy pursued by the Anglicans and others to create indigenous ecclesiastical institutions that eventually would be independent of European tutelage. The effort failed in part, however, because church authorities came to think that religious discipline had grown too lax during Crowther's episcopate but especially because of the rise of prejudice. Crowther was succeeded as bishop by a British cleric. Nevertheless, the acceptance of Christianity by large numbers of Nigerians depended finally on the various denominations coming to terms with local conditions and involved participation of an increasingly high proportion of African clergy in the missions.

In large measure, European missionaries were convinced of the value of colonial rule, thereby reinforcing colonial policy. In reaction some African Christian communities formed their own independent churches.

Data as of June 1991