One of the seven original dioceses of 1877, Kottayam has produced several Catholicoi and is headquartered at the MD Seminary.
Counts above reflect Orthodox-held institutions only; churches, chapels, and other properties currently under schismatic occupation are catalogued separately below and are not included in these totals.
The Diocese of Kottayam was established in 1877 as one of the seven original dioceses created after the Veliyanad Synod, convened under Patriarch Ignatius Peter IV of Antioch. It began with twenty churches under its first Metropolitan, Kadavil Paulose Mar Athanasios. Its legacy was shaped by figures who became Catholicos of the East, including Paulose Mar Ivanios (Baselios Paulose I) and Geevarghese Mar Philoxenos (Baselios Geevarghese I), and by the saint Vattasseril Geevarghese Mar Dionysius.
A significant era was the leadership of Kuriakose Mar Gregorios (Pampady Thirumeni) from 1929 to 1965, during which the Pampady Dayara (Mar Kuriakose Dayara) served as the diocesan seat. On 21 April 1982 the Holy Episcopal Synod divided the territory into the dioceses of Kottayam, Kottayam Central and Idukki. Geevarghese Mar Ivanios took charge of the Kottayam Diocese and led it through twenty-eight years of growth until his death in 2013. The diocese is headquartered at the Kuriakose Mar Gregorios Centre, MD Seminary, Kottayam, under Metropolitans such as H.G. Yuhanon Mar Dioscoros, and administers many parishes, chapels, educational institutions and charitable missions such as MGM Abhaya Bhavan.
8 districts, listed alphabetically.