The diocese covers a land area of 9,583 square kilometers and includes the entire civil districts of Thanjavur, Thiruvarur and Nagapattinam (except for the two taluks or civil administration units of Papanasam and Kumbakonam in the district of Thanjavur). It also covers six taluks of Pudukottai district and two taluks of Cuddalore district. Thanjavur, Thiruvarur and Nagapattinam are considered important towns of the area.
In 2017, Thanjuvar diocese has a total population of 5,092,290. Tamils and Telegus are the main ethnic groups here.
Tamil and Telegu are the languages spoken in the diocese.
The diocese of Thanjavur was erected by bifurcating the diocese of Mylapore on Nov. 23, 1952. The diocese of Thanjavur is the result of the work of the Portuguese Padruado Missionaries from Goa; Franciscans, Augustinians, Jesuits, Paris Foreign Missions Society (MEP), Salesians and the diocesan clergy.
On March 25, 1953, Bishop R.A. Sundaram became the first bishop of Thanjavur. Under his leadership, the diocese developed steadily. He retired in 1986 after 33 years of episcopal ministry. His successor, Archbishop P. Arokiaswamy, took charge on Nov. 26, 1986. He retired in July 1997. Father M. Devadass Ambrose was ordained bishop of Thanjavur on Sept. 24, 1997.
Towns are governed by municipalities, whereas villages and small towns are administered by local bodies called panchayats. The members of the local bodies are elected by adult suffrage.
The diocesan area is well connected in terms of transport infrastructure by roads and railway. The nearest airport is in Trichy city.
The per capita income here is Rs 16,261 ($362) as of November 2006. The districts of Thanjavur and Thiruvarur are collectively called the "rice bowl" of Tamil Nadu. The area known as Cauvery Delta is well known for its farming as the river Cauvery flows through it. Fishing is a major industry in the Nagapattinam district.
Government and private operators provide extensive telecommunication facilities here. The diocese is well served by local cable TV networks.
The literacy rate is 76.12 percent.
Carnatic music, one of the two classical music styles of India, originated in this area. Every year, thousands of Carnatic musicians visit Thiruvayaru to pay homage to Sri Thyagaraja, founder of the classical tradition. This area is also known for its folk arts such as shadow puppetry and the traditional Karakatam dance.