Companiganj Upazila (Noakhali district) with an area of 305.33 sq km, is surrounded by Senbgh and Daganbhuiyan upazilas on the north, Noakhali Sadar and Sandwip upazilas on the south,Sonagazi and Mirsharai upazilas on the east, Noakhali Sadar upazila on the west. 

Main rivers are Little Feni and Bamni.

Companiganj (Town) stands six km to the south of Maijdi Road. The town consists of six mouzas. It has an area of 6.5 sq km. The town has a population of 17340; male 52.77%, female 47.23%; population density per sq km 2668. The town has one dakbungalow.

Administration Companiganj thana, now an upazila, was established in 1888. The upazila consists of 11 union parishads, 39 mouzas and 41 villages. 

Archaeological heritage and relics Statue of Devi Kali (Sirajpur Union, eighteenth century).

Historical events During the War of Liberation quite a few encounters were held between the Mukti Bahinis and the Pak army in Companiganj upazila in which seven Muktijoddhas including Sadar BLF Commander Ohidur Rahman Wadud were killed.

Marks of the War of Liberation Mass grave near Sluice Gate no 16 of the upazila.

Population 183351; male 49.71%, female 50.29%; Muslim 91.85%, Hindu 8.10% and Christian 0.05%; population density 601 per sq km.

Religious institutions Mosque 242, temple 10, most noted of which is Budi Mosque at Basurhat and Jagannath Bari Mandir (Char Hazari).

Literacy and educational institutions Average literacy 34.5%; male 41.5% and female 27.8%. 

Educational institutions: government college 1, non-government college 2, government high school 2, non-government high school 26, madrasa 9, technical institution 1, government primary school 57, non-government primary school 19. 

Noted educational institutions: Basurhat AHC Government High School (1911), Bamni High School (1914), Basurhat Islamia Senior Madrasa (1914), Bamni Achhia Senior Madrasa (1915).Cultural organisations Club 22, public library 3, cinema hall 1, playground 26. 

Main occupations Agriculture 27.15%, agricultural labourer 18.08%, wage labourer 2.86%, commerce 10.49%, service 21.68%, transport 2.12%, fishing 1.01%, house renting out 1.47% and others 16.61%.

Land use Total cultivable land 22965.24 hectares; fallow land 394.58 hectares; single crop 58.93%, double crop 25.13% and treble crop 15.94%; cultivable land under irrigation 2.23%.

Land control Among the peasants 38% are landless, 30% small, 22% intermediate and 10% rich; cultivable land per head 0.26 hectare.

Value of land The market value of the land of the first grade is approximately Tk. 8000 per 0.01 hectare.

Main crops Paddy, wheat, potato, brinjal, sugarcane, tomato, chilli. Extinct or nearly extinct crops Linseed, sesame, jute, peanut, mustard seed and varieties of pulses. 

Main fruits Mango, jackfruit, coconut, black berry, papaya, betel nut, banana. Fisheries, dairies and poultries Poultry 18, fishery 60, hatchery 1. Communication facilities Roads: pucca 30 km, semi pucca 9.5 km and mud road 352 km. 

Traditional transport Palanquin, horse carriage, bullock cart and boat. These means of transport are either extinct or nearly extinct. 

Manufactories Flour mill 10, oil mill 3, ice factory 8, welding 5. Cottage industries Bamboo work 40, goldsmith 36, blacksmith 37, wood work 27, bidi 1. 

Hats, bazars and fairs Total number of hats and bazars are 19, most noted of which are Basurhat, Tal Muhammad Hat, Natun Bazar, Bangla Bazar; fair 1, Chaitra Sankranti Mela. 

Main exports Rice, coconut, betel nut, banana, vegetables. 

NGO activities Operationally important NGOs are Brac, ASA, Proshika, LRDA. 

Health centres Upazila health complex 1, family planning centre 7 and satellite clinic 1.