The Eastern Catholic Churches: A Reference Guide

A reference resource of the Likoudis Legacy Foundation.

Twenty-three Eastern Catholic Churches sui iuris are in full communion with the Bishop of Rome. Together with the Latin Church they make up the twenty-four autonomous Churches of the Catholic communion. They are not rites or usages within a single Church, and they are not Latin dioceses that happen to worship differently. Each is a Church in its own right, with its own hierarchy, its own synodal governance, its own liturgical and spiritual patrimony, and its own canonical discipline under the Codex Canonum Ecclesiarum Orientalium.

Pope Leo XIII, in the apostolic constitution Orientalium dignitas of 30 November 1894, affirmed the dignity of the Eastern Churches and the obligation to preserve their traditions intact.

Grouped by ecclesial origin

The most illuminating way to read the list is by where each Church came from. This grouping shows at a glance which separated communion each entered into union with Rome from, and it is the frame within which reunion questions are properly discussed.

• From the Assyrian Church of the East — Chaldean, Syro-Malabar
• From the Oriental Orthodox Churches — Armenian, Coptic, Ethiopian, Eritrean, Syriac, Syro-Malankara
• From the Orthodox Church — Ukrainian, Melkite, Romanian, Ruthenian, Slovak, Hungarian, Križevci, Bulgarian, Greek, Macedonian, Albanian, Russian, Belarusian
• With no separated counterpart — Maronite, Italo-Albanian

The Maronite Church is the one Eastern Church that holds it was never severed from communion with Rome. The Italo-Albanian Church, Byzantine in rite, likewise has no Orthodox counterpart.

The twenty-three Churches by liturgical tradition

Alexandrian tradition

Armenian tradition

East Syriac tradition

West Syriac tradition

Byzantine (Constantinopolitan) tradition

On statistics

Membership figures for these Churches move constantly, and they have moved violently in the last decade. War in Ukraine, displacement across Iraq and Syria, and rapid diaspora growth in North America, Australia and Western Europe have all reshaped the numbers. Rather than freeze a snapshot that will be wrong within a year, this page points to the sources that maintain them:

• The Annuario Pontificio, the Holy See’s own annual directory, is the authoritative record of jurisdictions and hierarchs.
• The Catholic Near East Welfare Association maintains current profiles of each Eastern Church.
• For the United States specifically, there are roughly 575,000 Eastern Catholics across eighteen eparchies, the largest being Chaldean and the smallest smaller than the least populous Latin diocese in the country.

By membership the six largest are the Syro-Malabar, Ukrainian Greek Catholic, Maronite, Melkite, Chaldean and Armenian Catholic Churches, which together account for roughly eighty-five per cent of all Eastern Catholics.

Why this matters pastorally

Eastern Catholics are Catholics without qualification. An Eastern Catholic presenting himself at a Latin parish is not a guest from another confession; he is a member of the same Church approaching a different ritual expression of it. The governing canons are CIC 844 §2 and CCEO 671, and the practical questions that arise in parishes — communion, marriage, ascription to a Church sui iuris, the baptism and chrismation of infants together — are matters of Eastern canonical discipline rather than Latin custom.

In February 2026 the Holy See established an Eastern Canonical Commission to undertake a review of the CCEO, following repeated formal requests from the heads of the twenty-three Churches sui iuris. Diocesan offices with Eastern Catholic faithful in their territory should expect this area to develop.

Hierarchs and canonical status verified July 2026. Compiled by the Likoudis Legacy Foundation, continuing the reference work of Dr. James Likoudis.