Pope Gregory XIV in 1836 made Madurai into an Apostolic Prefecture; in 1846 it was raised to an apostolic Vicariate and entrusted to the Fathers of the Society of Jesus. On September 1, 1886 the vicariate became a diocese with the Episcopal residence fixed at Tiruchirapalli with Msgr. Alexis Canoz S.J. as its first Bishop and came to be called the DIOCESE OF TIRUCHIRAPALLI. He was succeeded by Msgr. John Barthe, S.J. (1890-1913) and later by Msgr. Augustine Faisandier, S.J. (1914-1935. In 1932 Pope Pius XI separated the south eastern part of the Diocese known as the Fishery Coast and created the Diocese of Tuticorin

In 1938 another division was made by Pope Pius XII 1) The whole civil district of Ramnad except the parish of Mookkur and 2) the taluks of Sankarankoil, Tenkasi, Ambasamudram, Tirunelveli and Kovilpatti excepting a portion along the coast-all belonging to the civil district of Tirunelveli and 3) six out of the eight taluks of Madurai district: Madurai, Tirumangalam, Periyakulam, Kodaikanal, Nilakottai and Melur were cut off from the diocese of Tiruchirapalli and made into the Diocese of Madurai. The then bishop of Tiruchirapalli Msgr. J.P. Leonard, S.J. (1936-1938) was transferred to the new See and the Diocese of Tiruchirapalli was handed over to the Diocesan Clergy with Msgr. James Mendonca, (1938-1971) as its first Indian Bishop. When Msgr. James Mendonca retired in 1971, Msgr. Thomas Fernando was transferred from the See of Tuticorin to the Diocese of Tiruchirapalli.

Rev. Fr. Sengole Lawrence Gabriel, was elected on October 26 of 1990 and consecrated as the Bishop of Tiruchirapalli, on 30th December 1990 and took charge of the See of Tiruchirapalli on the same day. At his request, Bishop Gabriel was relieved from the responsibility of the See of Tiruchirapalli and Bishop Peter Fernando, the Co-adjutor Bishop of Tuticorin was appointed as the Apostolic Administrator on 14-10-1997.

Bishop Antony Devotta was consecrated and took charge of the See of Tiruchirapalli on 28th January 2001. Having reached the age 75, Bishop Antony Devotta submitted his resignation and the Holy Father Francis accepted his resignation and appointed Bishop Devadoss Ambrose, Bishop of Thanjavur, as the Apostolic Administrator of Trichy diocese on 14th July 2018 and Bishop Devadass Ambrose took charge of the Diocese on 12 August 2018. After 3 years, on 29th June, on the Feast Day of St. Peter and Paul, the Announcement was made that the Diocese of Tiruchirappalli is blessed with a new Bishop S. Arokiaraj, from its own soil and he was consecrated as Bishop on 15th August 2021.

The present diocese of Tiruchirapalli comprises parts of 3 districts at present: Taluks of Tiruchirapalli and Manaparai (from the District of Tiruchirapalli), Taluks of Kulithalai (from the District of Karur) and Taluks of Kulathur (from the District of Pudukottai). The river Cauvery is the border line between Tiruchirapalli Diocese and the Dioceses of Coimbatore, Thanjavur and Kumbakonam.

The diocese consists of 73 parishes grouped into five Vicariates: Vicariate of Puthur, Crawford, Ponmalai, Keeranur and Manaparai.

Former Prelates:

	Alexis Canoz (1846-1888)
	John Barthe S.J. (1890-1913)
	Augustine Faisandier S.J. (1914-1935)
	John Peter Leonard S.J. (1936 transferred to Madurai – 1938)
	James Mendonca (1938-1971)
	Thomas Fernando (1971 – retired in 1990)
	S. L. Gabriel (1990 – retired in 1997)
	Bishop Peter Fernando (Administrator 1997-2000)
	Bishop Antony Devotta (2001 – retired in 14 August 2018)
	Bishop M. Devadass Ambrose (Apostolic Administrator 2018 – 2021)
	Bishop Arokiaraj (2021 – )