Followers of Islam are estimated to comprise 60% of Sierra Leone's population, those of Christianity 30%, and those of African indigenous religion, 10%.

The Sierra Leone constitution provides freedom of religion and the government generally protects this right and does not tolerate its abuse. Unlike many other African countries, the religious diversity of Sierra Leone has seldom led to conflict.
 
Islam
Statistics for Islam in Sierra Leone estimate a Muslim population of 3,610,585, representing around 60 percent of the country's total population. There are 18 ethnic groups in the country, the two largest being the Temne and Mende. The Temnes are the main tribe in the north and are predominantly Muslim.

In the early 18th century Fulani and Mande-speaking tribesmen from the Fouta Djallon region of present-day Guinea converted many Temne of northern Sierra Leone to Islam. During the period of British colonialization, the spread of Islam was indirectly favored by the spread of peace and order and stimulating trade. The Europeans broke down the traditional structures of society, introduced new educational and social ideas, opened markets, attracted migrant Africans to growing cities, and thereby indirectly promoted Islam as a form of authority and as an expression of cohesion among displaced peoples. Islam also continued to spread after independence in 1961; in 1960 the Muslim population was 35 percent and grew to 60 percent by 2000.

Roman Catholicism
The Roman Catholic Church in Sierra Leone is part of the worldwide Roman Catholic Church, under the spiritual leadership of the Pope and curia in Rome.

There are approximately 175,000 Catholics in Sierra Leone - around 3% of the total population. The country is divided into three dioceses including one archdiocese.