The Diocese of Thanjavur was bifurcated from the Diocese of Mylapore on November 23, 1952 by the Holy See, and was erected into a diocese by the Papal Bull Ex Primaevae Ecclesiae


Missionaries in the Diocese: The territory that constitutes the present Diocese of Thanjavur has been the field of the heroic labour of the Portuguese Padruado Missionaries from Goa, Franciscans, Augustinians, Jesuits, Foreign Missionary Society of Paris (MEP), Salesians and the Diocesan Clergy.