Many Belizeans are of mixed ancestry, most of them descendant of immigrants. Mestizos (of mixed Maya Indian and European ancestry) are the largest ethnic group, accounting for more than two-fifths of the population. English-speaking people of largely African and African-European ancestry, who are called Creoles, account for nearly one-third of the population and predominate in the central coastal regions. Mestizos predominate in the more sparsely inhabited interior, along with the Maya, who account for one-ninth of the population. Several thousand Garifuna, formerly called Black Caribs, who are descendants of the Carib Indians and Africans exiled from British colonies in the eastern Caribbean ( Lesser Antilles) in the 18th century, live in communities on the south coast. People of European and East Indian ancestry are also present, as are smaller numbers of Chinese, Arabs, and others.

English is the official language, but most of the population also speak a Creole patois. The Mestizos speak Spanish, and the Maya speak Spanish or Yucatec, Mopan, or Kekchi Maya. The Garifuna speak their own Arawakan-based language and also English or Spanish. Many Belizeans are multilingual.

Anglicans, who established the first church in the early 19th century, were soon followed by Baptist and Methodist missionaries. The Roman Catholic church was established in 1851, and nearly three-fifths of the population are adherents of that religion. Protestants account for more than one-third of the population, with the largest denominations being Anglican, Pentecostal, Methodist, Seventh-day Adventist, and Mennonite. Evangelical and fundamentalist churches, many of them based in the United States, are small but growing rapidly.

Migration patterns are changing the ethnic composition of the population. Groups of Mennonites migrated from Mexico and Canada after 1958 and established agricultural settlements to the north and west of Belize City. In the 1980s, Belize received an estimated 25,000 Spanish speakers—equivalent to nearly one-seventh of the nation's population at the time—as refugees fled war-torn Guatemala and El Salvador, while an even larger number of Belizeans, mostly English-speaking Creoles, migrated to the United States. Continuing immigration and a high rate of natural increase added some 70,000 people between 1980 and the end of the century.

The service sector of the economy—including trade, tourism, and administration—has accounted for the largest share of the gross national product (GNP) since the early 1980s, when it overtook agriculture, forestry, and fishing. Nearly half the labour force and the GNP are now sustained by services. Tourism expanded rapidly in the 1980s and '90s and became a major source of foreign exchange. Fishing, boating, and swimming along the reef are popular, and ecotourism in the interior has grown