The Archdiocese of Chittagong comprises the 17 civil districts of Chittagong: Cox's Bazar, Bandarban, Rangamati, Khagrachori, Noakhali, Feni, Laxmipur, Bhola, Patuakhali, Pirojpur, Barisal, Jhalakathi, Borguna, Gopalganj, Madaripur and Shariatpur.

The Archdiocese is in the southern part of Bangladesh and covers 33% of the total surface of the country, making it physically its largest diocese.

In 1537, Portugal established a settlement of Dianga in the area of Chittagong, bringing the Catholic Church and missionaries with them.

Jesuit Father Francesco Fernandez, who came to Dianga in 1598, and who was blinded and tortured and died in captivity on November 14, 1602, is Bengal's first martyr.

The newly erected bishopric then included Chittagong, Noakhali, Barisal, Gournadi, Narikelbari, Haflong, Badarpur, Akyab, Sandoway, Gyeithaw and Chaugtha.

in present Myanmar were handed over to the La Salette Fathers in the future Apostolic Prefecture of Akyab in 1937–38.

On February 2, 2017 the bishopric was elevated by Pope Francis to metropolitan rank as Archdiocese of Chittagong, with two suffragans, and on December 28, 2018 was renamed Chattogram.