The Diocese of Kumbakonam was separated from the Archdiocese of Pondicherry on September 1, 1899 by the Apostolic Letter of Pope Leo XIII.

The Diocese of Kumbakonam comprises 15 civil taluks - 5 from the Thanjavur district and 4 from the Trichirapalli district and 6 from Perumbalur district. The taluks in Thanjavur district are: Kumbakonam, Thiruvaiyaru, a portion of Papanasam, a portion of Valangaiman and Thiruvidaimarudur. The taluks in the Trichirapalli district are Musiri, Lalgudi, Thuraiyur and a portion of Trichy taluk. The taluks in Perambalur district are Ariyalur, Kunnam, Senthruai, Udaiyarpalayam, Veppanthattai and Perambalur. The diocese lies in Tamil Nadu. It has 6 Vicariates: Kumbakonam, Michaelpatti, Lalkudi, Pullambadi, Perambalur and Jayankondam. The total parishes are 72.