Growing from a small congregation of fifteen families, the Diocese of Delhi was established in 1975 and has been led by figures such as Paulos Mar Gregorios.
Although the Catholicate was re-established in India in 1912, the Orthodox presence in Delhi remained very limited until regular Holy Qurbana began in 1942 through the ministry of Fr. Mathews, later His Holiness Baselios Marthoma Mathews II. The efforts of Metropolitans Alexios Mar Theodosius and Thoma Mar Dionysius, and of the missionary Fr. Pathros (later H.G. Pathros Mar Osthathios), inspired the faithful to establish a permanent parish for some fifteen families, about 150 individuals. The 1952 celebration of the nineteenth centenary of St. Thomas's arrival in India, attended by President Dr. Rajendra Prasad and Prime Minister Jawaharlal Nehru, strengthened this vision, and by 1952 a formal parish had been established with its first resident Vicar.
Under Fr. K.C. Thomas, and with the founding of the Delhi Orthodox Syrian Church Society in 1961, the construction of St. Mary's Orthodox Church (now Cathedral) at Hauz Khas became possible through the support of Church leaders and the sacrifices of the faithful; it was consecrated in 1968. The Holy Synod created the Diocese of Delhi in 1975. H.G. Dr. Paulos Mar Gregorios assumed charge as its first Metropolitan in 1976 and established the Delhi Orthodox Centre in 1984. After his death in 1996, H.G. Job Mar Philoxenos led the diocese's expansion until 2011. It is now led by H.G. Dr. Yuhanon Mar Demetrios.
8 districts, listed alphabetically.