Tongans are ardent church goers. Church service usually follows a call and response structure. Singing in the church is often done a cappella. Although a church attends primarily to the spiritual needs of the population, it also functions as the primary social hub. As consequence people who go to a church of another denomination are absolutely not shunned.

Sunday in Tonga is celebrated as a strict sabbath, enshrined so in the constitution, and despite some voices to the opposite, the Sunday ban is not likely to be abolished soon. No trade is allowed on Sunday, except essential services, after special approval by the minister of police. Those that break the law risk a fine or imprisonment.

According to the official census in 1996, 41% of the population of Tonga belonged to the Free Wesleyan Church of Tonga, 16% to the Roman Catholic Church, 14% to the Church of Jesus Christ of Latter-day Saints (Mormons), 12% to the Free Church of Tonga, 17% to other groups.

 However, both Roman Catholics and Mormons state that the number of their adherents is higher than reported, and a 2006 survey conducted by the Free Wesleyan Church revealed its membership comprised only 35 percent of the population.[1] The Tokaikolo Church (a local offshoot of the Methodist Church), Seventh-day Adventists, Assemblies of God, Anglicans are also present.

Other than Christian denominations the next largest religion is of the Baha'i Faith.[2] Hinduism and Buddhism have begun to gain traction, growing from 0.2% to 0.4% of the population(or 175 to 383 combined) in five years. Meanwhile, Islam has shrunk to 24 people, from its peak of 47.

The Church of Jesus Christ of Latter-day Saints claims it has over 60,600 members which is about 57% of the population of Tonga. According to The Church of Jesus Christ of Latter-day Saints, Tonga has a higher per-capita number of Latter-day Saints than any other country in the world.

 However, according to 2011 census, only 18.01% of Tongans belong to LDS Church and Tongans belonging to mainstream Christian denominations represent majority of the population.

The Bah Faith in Tonga started after being set as a goal to introduce the religion in 1953, and Bahs arrived in 1954. With conversions and pioneers the first Bah; Local Spiritual Assembly was elected in 1958.

 Less than forty years later, in 1996, the Bahs of Tonga established their paramount Bah school in the form of the Ocean of Light International School.

Around 2004 there were 29 local spiritual assemblies and about 5% of the national population were members of the Bah; Faith though the Tonga Broadcasting Commission maintained a policy that does not allow discussions by members of the Bah Faith of its founder, Bah on its radio broadcasts.

 Foreign missionaries are active in the country and operate freely. The Constitution of Tonga provides for freedom of religion, and the government generally respected this right in practice.

 The US government found that there were no reports of societal abuses or discrimination based on religious belief or practice in 2007.