The Romanian Orthodox Church, or Patriarchate of Romania, is an autocephalous Eastern Orthodox church in full communion with other Eastern Orthodox Christian churches, and one of the nine patriarchates in the Eastern Orthodox Church. Since 1925, the church's Primate has borne the title of Patriarch. Its jurisdiction covers the territories of Romania and Moldova, with additional dioceses for Romanians living in nearby Serbia and Hungary, as well as for diaspora communities in Central and Western Europe, North America and Oceania. It is the only autocephalous church within Eastern Orthodoxy to have a Romance language for liturgical use.

Romanian is the official and main language of Romania and Moldova. Romanian is part of the Eastern Romance sub-branch of Romance languages, a linguistic group that evolved from several dialects of Vulgar Latin which separated from the Western Romance languages in the course of the period from the 5th to the 8th centuries. To distinguish it within the Eastern Romance languages, in comparative linguistics it is called Daco-Romanian as opposed to its closest relatives, Aromanian, Megleno-Romanian, and Istro-Romanian. It is also spoken as a minority language by stable communities in the countries surrounding Romania, and by the large Romanian diaspora. In total, it is spoken by 25 million people as a first language.