Indian Orthodox Christians are primarily concentrated in Kerala, India and account for over 2.5 million faithful worldwide. The Church has dioceses and churches in most parts of India as well as in the United States, Canada, United Kingdom, Western Europe, Persian Gulf nations, Malaysia, Singapore, Australia, and New Zealand. The head of the Indian Orthodox Church is the Catholicos of the East and Malankara Metropolitan, whose seat is in Kottayam, Kerala, India. The Catholicos of the East is the designee for the Apostolic throne of St. Thomas.

The Constitution (English/ Malayalam) of the Indian Orthodox Church was developed in 1934 for every member to follow. The present Catholicos of the East and Malankara Metropolitan is His Holiness Baselios Marthoma Paulose II.

H. H. Baselios Marthoma Mathews III

9^th Catholicos of the East (2021-present)

H. H. Baselios Marthoma Paulose II

8^th Catholicos of the East (2010-2021)

H. H. Baselios Marthoma Didymos I

7^th Catholicos of the East (2005-2010)

H. H. Baselios Marthoma Mathews II

6^th Catholicos of the East (1991-2005)

H. H. Baselios Marthoma Mathews I

5^th Catholicos of the East (1975-1991)

H. H. Baselios Augen I

4^th Catholicos of the East (1964-1975)

H. H. Baselios Geevarghese II

3^rd Catholicos of the East (1929-1964)

H. H. Baselios Geevarghese I

2^nd Catholicos of the East (1925-1928)

H. H. Baselios Paulos I

1^st Catholicos of the East (1912-1913)

The two North American Dioceses are divided into Northeast and Southwest regions. St. Gregorios is one of over 50 parishes under the leadership of the Northeast American Diocese Metropolitan, His Grace Zachariah Mar Nicholovos, with headquarters in New York. NorthEast AMerican Diocese

H. G. Zachariah Mar Nicholovos

Northeast American Diocese Metropolitan

The Southwest Diocese is located in Texas, under the leadership of His Grace Dr. Zacharias Mar Aprem Southwest Diocese

H. G. Dr. Zacharias Mar Aprem

Southwest American Diocese Metropolitan