The Eastern Catholic Churches or Oriental Catholic Churches, also called the Eastern-Rite Catholic Churches, Eastern Rite Catholicism, or simply the Eastern Churches, are 23 Eastern Christian autonomous (sui iuris) particular churches of the Catholic Church, in full communion with the Pope in Rome. Although they are distinct theologically, liturgically, and historically from the Latin Church, they are all in full communion with it and with each other. Eastern Catholics are a distinct minority within the Catholic Church; of the 1.3 billion Catholics in communion with the Pope, approximately 18 million are members of the eastern churches.
The majority of the Eastern Catholic Churches are groups that, at different points in the past, used to belong to the Eastern Orthodox Church, the Oriental Orthodox churches, or the historic Church of the East; these churches underwent various schisms throughout history. The Eastern Catholics churches are communities of Eastern Christians that either returned to communion with the Pope, or in some cases have never broken communion. The Pope's recognition of Eastern Catholics who returned to communion has been a point of controversy in ecumenical relations with the Eastern Orthodox and other churches. The five historic liturgical traditions of eastern Christianity, comprising the Alexandrian Rite, the Armenian Rite, the Byzantine Rite, the East Syriac Rite, and the West Syriac Rite, are all represented within Eastern Catholic liturgy. Consequently, the Catholic Church consists of six liturgical rites, the eastern rites along with the liturgical rites of the Latin Church. On occasion, this leads to a conflation of the liturgical word "rite" and the institutional word "church". Although some theological issues divide the Eastern Catholic Churches from other eastern churches not in communion with the pope, some Eastern Catholic jurisdictions admit members of the latter to the Eucharist and the other sacraments, as governed by applicable Eastern Catholic canon law.