The Christian faith arrived in Chattogram in 1517 through the Portuguese merchants. Portuguese merchants had settled here in 1537. Three churches were set up in 1600 at Patherghata, Jamalkhan and Diang.

Father Francesco Fernandez, S.J. who came to Chattogram in 1598, and who was blinded and tortured and died in captivity on November 14, 1602, is the Bengal’s first martyr.

In 1845 Chattogram became the seat of the first Vicar Apostolic of Eastern Bengal, and later the administration was transferred to Dhaka.

Noahkhali was also the first place to have the Holy Cross Missionaries who arrived there in June 1853.

The Diocese of Chittagong was Canonically erected on May 25, 1927, taking away a good half of the territory that comprised the then Diocese of Dhaka. The Diocese then comprised of Chittagong, Noakhali, Barisal, Gournadi, Narikelbari and other parts in India and Myanmar.

The newly erected Diocese of Chittagong in 1927 was entrusted to the care of the Canadian Province of the Congregation of Holy Cross. When the new ecclesiastical province of Dhaka was created in July, 1950, Chittagong became a sufragan of Dhaka. Later in 1952, portions of the Diocese of Chittagong that were situated in Assam (India) were detached to form a separate ecclesiastical unit, called the Prefecture of Haflong, and later the Diocese of Silchar, which is called now the Diocese of Agartola and the Diocese of Aijwal.

Since the erection in 1927, the geographical map of Chittagong Diocese has changed twice in the past. Barisal has emerged as a separate Diocese on 29^th December 2015 taking away 17,516 square kilometers from 9 civil districts from the territory of Chittagong Diocese and some portion of Khulna Diocese. His Holiness, Pope Francis has established the country’s second Ecclesiastical Province in Chattogram, making Khulna and Barisal as its suffragan dioceses on 2nd February 2017.

In 2019, Chittagong Diocese has celebrated the 5^th centennial anniversary of the arrival of Christian faith in Chattogram, Bengal.