This is a list of Christian denominations by number of members. It is inevitably partial and generally based on claims by the denominations themselves. The numbers should therefore be considered approximate and the article is an ongoing work-in-progress. The list includes the Catholic Church (including Eastern Catholic Churches), Protestant denominations with at least 0.2 million members, the Eastern Orthodox Church (and its offshoots), Oriental Orthodox Churches (and their offshoots), Nontrinitarian Restorationism, independent Catholic denominations, Nestorianism and all the other Christian branches and denominations with distinct theologies or polities. Christianity is the largest religious group in the world, with an estimated 2.3 to 2.6 billion adherents in 2020.

Christian denominational families

The various denominations of Christianity fall into several large families, shaped both by culture and history. Christianity arose in the first century AD after Rome had conquered much of the western parts of the fragmented Hellenistic empire created by Alexander the Great. The linguistic and cultural divisions of the first century AD Roman Empire with, broadly speaking, a Latin West and a Greek East, but also with significant areas in North Africa where Coptic was the dominant language, and areas in the Near East where Syriac or Aramaic was the dominant language, were reflected in the early Christian church. The church was called "Catholic" meaning "universal" from very early in the second century, a tacit acknowledgement of the many different cultures it encompassed. Early Christianity suffered great, although intermittent, persecution from the state until Emperor Constantine the Great issued the Edict of Milan in 313 AD, legalizing Christianity. Shortly after the cessation of persecution, the Church had the luxury of reflecting on the meaning of its own teachings for the first time. Significant disputes arose, particularly over the nature of Christ and the relationship between Christ, the Father, and the Spirit. The Church chose to address those disputes with Ecumenical councils, the first four of which were at Nicaea, Constantinople, Ephesus and Chalcedon. The first two of these councils, the First Council of Nicaea and the First Council of Constantinople gave birth to the Nicene Creed which has become the touchstone for Christian beliefs. Both of the next two Councils, the Council of Ephesus, and the Council of Chalcedon led to significant ruptures in the Church. Many Christians espousing the minority position at these two councils, even after extensive discussion and attempts at reconciliation, chose to strike out on their own, rather than to accept the positions held by the majority of the church fathers at the councils. Refusing to accept the Council of Ephesus, the Church of the East, encompassing many Syriac speaking Christians in what was then the far East of the Empire, split off in 431 AD. A few decades later, in 451 AD, after the Council of Chalcedon, the group that later became known as the Oriental Orthodox Churches, encompassing many Coptic speaking Christians in North Africa, also split off. In 1054 AD, an accumulation of misunderstanding, disrespect and genuine theological differences led to the Great Schism, dividing Greek speaking Christians who became the Eastern Orthodox, from Latin speaking Christians who kept the name Catholic, but increasingly prefaced it with the adjective "Roman". Beginning in 1517, the remaining western, Latin speaking church was itself rent asunder by the Reformation with many Christians rejecting papal authority and gathering together in new ways. Broadly speaking Protestantism has four streams: Lutheranism, Calvinism, Anabaptism, and Anglicanism. While all of these Christian groups from the Church of the East on, have their own subsequent splits, the fragmentation in Protestantism has been extreme, with tens of thousands of denominations. Some of these fragmented groups, particularly among the Eastern churches, have sought to return to Rome, and have reunited themselves under papal authority.

Christianity – 2.3 to 2.6 billion

Catholicism – 1.278–1.390 billion

Catholicism is the largest branch of Christianity and the Catholic Church is the largest among churches. About 50% of all Christians are Catholics. According to the annual directory of the Catholic Church or Annuario Pontificio of 2024, there were 1.390 billion baptized Catholics in 2022. In 2024, the World Christian Database reported 1.278 billion Catholics. That figure does not include independent denominations that self-identify as Catholic, numbering some 18 million adherents subscribing to Old Catholicism and other forms of Independent Catholicism. Figures below include the Annuario Pontificio of 2021–2024 that provided 2019–2022 statistics.

Latin Church – 1.327–1.372 billion

====Eastern Catholic Churches – 18 million ====

Canonically irregular groups

Sedevacantists

Protestantism – 0.6–1.1 billion

Protestantism is the second largest major group of Christians by number of followers. Estimates vary from 0.6 to 1.1 billion, or between 24% and 40% of all Christians. The main reason for this wide range is the lack of a common agreement among scholars as to which denominations constitute Protestantism. For instance, most sources include Anabaptism, Anglicanism, Baptists and non-denominational Christianity as part of Protestantism. However, widely used references like the World Christian Encyclopedia, which has been documenting the changing status of World Christianity over the past 120 years classifies Independent Christians as a separate category from Protestantism. Moreover, Protestant denominations altogether do not form a single structure comparable to the Catholic Church, or to a lesser extent the Eastern Orthodox communion. However, several different comparable communions exist within Protestantism, such as the World Evangelical Alliance, the Anglican Communion, the World Communion of Reformed Churches, the Baptist World Alliance, the World Methodist Council and the Lutheran World Federation. Regardless, 900 million is the most accepted figure among various authors and scholars, and thus is used in this article. Note that this 900 million figure also includes Anglicans, Anabaptists, Baptists, as well as multiple other groups that might sometimes disavow a common "Protestant" designation, and would rather prefer to be called, simply, "Christian". According to Mark Juergensmeyer of the University of California, "popular Protestantism" (that is to say all forms of Protestantism with the notable exception of the historical denominations deriving from the Protestant Reformation) is the most dynamic religious movement in the contemporary world, alongside resurgent Islam.

Historical Protestantism – 300–600 million

The number of individuals who are members of historical Protestant Churches totals to 300–600 million.

Anglicanism – 110 million

There are about 110 million Christians in Anglican tradition, mostly part of the Anglican Communion, the third-largest Christian communion in the world, with 42 members (provinces).

Baptist churches – 100 million

The worldwide Baptist community numbers about 100 million. However, the Baptist World Alliance, the world communion of Baptist churches, self-reports only 51 million baptized believers, as Baptists do not count children as members, since they believe in believer's baptism. Therefore, the BWA is the 9th largest Christian communion.

Lutheranism – 70–90 million

The number of adherents in the Lutheran denominations totals to 70–90 million persons (the Lutheran World Federation reports 77 million and is the sixth largest communion) being represented in the following churches:

Calvinism / Reformed churches – 70–80 million

The Reformed tradition is represented by 70–80 million people who hold membership in the following churches; the World Communion of Reformed Churches is the fourth-largest communion.

Methodism – 60–80 million

The Methodist movement is represented by 60–80 million people (a figure including adherents but non-members), found in denominations including the following; the World Methodist Council (WMC) is the fifth largest communion. Not all of the following churches are member churches of the WMC. The largest Methodist denomination, the United Methodist Church, had about 25 percent of their churches disaffiliate between 2019 and 2023, some of whom joined the Global Methodist Church, thus figures for the two denominations are an ongoing process.

Adventism – 23 million

Restoration Movement – 4 million

Anabaptism – 4 million

Hussites – 1.2 million

Plymouth Brethren – 1 million

The Plymouth Brethren number around 1 million members.

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Quakers – 0.4 million

Modern Protestantism – 400–500 million

The denominations listed below did not emerge from the Protestant Reformation of the 16th century or its commonly acknowledged offshoots. Instead, they are broadly linked to Pentecostalism or similar other independent evangelical and revivalistic movements that originated in the beginning of the 20th century. For this reason, several sources tend to differentiate them from Protestants and classify them together as Independents, Non-core Protestants etc. Also included in this category are the numerous, yet very similar non-denominational churches. Nonetheless, most sources combine their numbers to the Protestant tally, while others do not since these churches do not self-identify with mainline Protestant traditions. Despite the absence of centralized control or leadership, if considered as a single cohort, this will easily be the second largest Christian tradition after Roman Catholicism. According to the Center for the Study of Global Christianity (CSGC), there are an estimated 450 million Independents world-wide, as of mid-2019.

Pentecostalism – 170-280 million

Those who are members of the Pentecostal denomination number around 280 million people.

Non-denominational Christianity – 40–100 million

African initiated churches – 45-60 million

60 million people are members of African initiated churches.

Chinese Patriotic Christian Churches – 25 million

New Apostolic Church – 10 million

The New Apostolic Church has around 10 million members.

Local churches – 1 to 10 million

Messianic Judaism – 0.3 million

Messianic Judaism has a membership of 0.3 million people.

Eastern Protestant Christianity – 22 million

Eastern Protestant Christianity (or Eastern Reformed Christianity) encompasses a range of heterogeneous Protestant Christian denominations that developed outside of the Occident, from the latter half of the nineteenth century and yet keeps elements of Eastern Christianity, to varying degrees. Most of these denominations came into being when existing Protestant Churches adopted reformational variants of Eastern Orthodox liturgy and worship; while others are the result of reformations of Eastern Orthodox beliefs and practices, inspired by the teachings of Western Protestant missionaries. Some Protestant Eastern Churches are in communion with similar Western Protestant Churches. However, Protestant Eastern Christianity within itself, does not constitute a single communion. This is due to the diverse polities, practices, liturgies and orientations of the denominations which fall under this category.

Eastern Orthodoxy – 220 million

The best estimate of the number of Eastern Orthodox Christians is 220 million or 80% of all Eastern Orthodox Christians worldwide. Its main body consists of the various autocephalous churches along with the autonomous and other churches canonically linked to them, for the most part form a single communion, making the Eastern Orthodox Church the second largest single denomination behind the Catholic Church. In addition, there are several Eastern Orthodox splinter groups and non-universally recognized churches.

Autocephalous churches – 168 million

Autonomous churches – 5 million

Churches universally recognized as Orthodox but with disputed autocephaly – 6 million

Non-universally recognized churches – 16–18 million

Other separated Orthodox groups – 6 million

Oriental Orthodoxy – 62 million

The Oriental Orthodox Churches are those descended from those that rejected the Council of Chalcedon in 451. Despite the similar name, they are therefore a different branch of Christianity from the Eastern Orthodox (see above). There are an estimated 62 million Oriental Orthodox Christians, worldwide.

Autocephalous churches – 62 million

Autonomous churches

Churches not in communion

Nontrinitarian Restorationism – 43-65 million

A sixth group is composed by Nontrinitarian Restorationists. These groups are quite distinct from orthodox Trinitarian restorationist groups such as the Disciples of Christ, despite some shared history. ====Oneness Pentecostalism – 10-30 million ====

Latter Day Saint movement or Mormonism – 18 million

====Jehovah's Witnesses – 9 million ====

Minor denominations – 6 million

Independent Catholicism – 18 million

Various denominations that self-identify as Catholic, despite not being affiliated with the Catholic Church.

Nestorianism – 0.6 million

A seventh group is composed of Nestorians. Divisions occurred within the Church of the East, especially the schism of 1552, but by 1830 two unified patriarchates and distinct churches remained: the Assyrian Church of the East and the Chaldean Catholic Church (now an Eastern Catholic Church in communion with the Holy See).