The U.S. government estimates the total population at 22.6 million (July 2018 estimate).  The 2012 national census (the most recent) lists 70.2 percent of the population as Buddhist, 12.6 percent Hindu, 9.7 percent Muslim, and 7.4 percent Christian.  According to census data, the Theravada Buddhist community, which comprises nearly all the country’s Buddhists, is a majority in the Central, North-Central, Northwestern, Sabaragamuwa, Southern, Uva, and Western Provinces.

Tamils, mainly Hindu with a significant Christian minority, constitute the majority in the Northern Province and constitute the second largest group, after Muslims, in the Eastern Province.  Most Muslims self-identify as a separate ethnic group.  Tamils of Indian origin, who are mostly Hindu, have a large presence in the Central, Sabaragamuwa, and Uva Provinces.  Muslims form a plurality in the Eastern Province, and there are sizable Muslim populations in the Central, North-Central, Northwestern, Sabaragamuwa, Uva, and Western Provinces.  Christians reside throughout the country but have a larger presence in the Eastern, Northern, Northwestern, and Western Provinces, and a smaller presence in Sabaragamuwa and Uva Provinces.

Most Muslims are Sunni, with small Shia and Ahmadi minorities.  An estimated 82 percent of Christians are Roman Catholic.  Other groups include Church of Ceylon (Anglicans), the Dutch Reformed Church, Methodists, Baptists, Assembly of God, Pentecostals, The Church of Jesus Christ of Latter-day Saints, and Jehovah’s Witnesses.  Christian evangelicals and other “free” (evangelical and nondenominational Protestant) groups have grown in recent years, although there are no reliable estimates of their numbers.  According to the government, membership remains low compared to the larger Christian community.  Although the government does not recognize Judaism as an official religion, there is a small Jewish population living in different parts of the country.