The Armenian Apostolic Church is the world's oldest National Church, is part of Oriental Orthodoxy, and is one of the most ancient Christian communities.

Armenia is the first country to adopt Christianity as its official religion in 301 CE, in establishing this church.

The Armenian Apostolic Orthodox Church traces its origins to the missions of Apostles Bartholomew and Thaddeus in the 1st century and is an early center of Christianity.The official name of the Church is the One Holy Universal Apostolic Orthodox Armenian Church.

It is sometimes referred to as the Gregorian Church, but the latter name is not preferred by the Church, as it views the Apostles Bartholomew and Thaddeus as the founders, and St. Gregory the Illuminator as merely the first official governor of the Church.