Chittagong Division (), officially Chattogram Division, is geographically the largest of the eight administrative Divisions of Bangladesh. It covers the southeasternmost areas of the country, with a total area of and a population according to the 2022 census of 33,202,326, which made it the second most populous division of Bangladesh and the 45th most populous subnational entity in the world â more populous than all but 43 other countries. Chittagong Division is home to Cox's Bazar, the longest natural sea beach in the world; as well as St. Martin's Island, Bangladesh's sole coral reef.
Chittagong as an administrative division was established in 1829 to serve as an administrative headquarters for five of Bengal's easternmost districts, with the Chittagong District serving as its headquarters. In East Pakistan, the division's Tippera district was renamed as Comilla District in 1960.
In 1984, fifteen districts were created by separating and reducing the original five districts of Chittagong, Comilla, Hill Tracts, Noakhali and Sylhet:
Sylhet, Habiganj, Moulvibazar and Sunamganj districts were moved from the Chittagong Division to create the newly established Sylhet Division in 1995.
Chittagong Division is presently subdivided into eleven districts (zilas) and thence into 100 sub-districts (upazilas). The first six districts listed below comprise the north-western portion (with 37.6% of the area, but 58.3% of the population) of the present Chittagong Division, while the remaining five comprise the south-eastern portion (62.4% of the area, 41.7% of the population), the two portions being separated by the lower (or Bangladeshi) stretch of the Feni River; the upland districts of Khagrachhari, Rangamati and Bandarban together comprise that area previously known as the Chittagong Hill Tracts. The six districts in the north-west will now form the new Cumilla Division.
According to the 2022 Census of Bangladesh, Chittagong Division had 7,528,333 households and a population of 33,202,326, 33.7% of whom lived in urban areas. The population density was 979 people per km<sup>2</sup>. 90.11% were Muslims, 6.61% Hindus, 2.92% Buddhists, 0.22% Christians and 0.14% others.