Its official population count was 679,012 inhabitants in 2012; however, over two million people live in the larger urban area.

[5] At the beginning of the 19th century, Cotonou (then spelled "Kutonou") was a small fishing village, and is thought to have been formally founded by King Ghezo of Dahomey in 1830.

[5] In 1851 the French Second Republic made a treaty with King Ghezo that allowed them to establish a trading post at Cotonou.

[6] During the reign of King Glele (1858–89), the territory was ceded to the Second French Empire by a treaty signed in 1878.

The city has established transportation infrastructure including air, sea, river (to Porto Novo), and land routes that facilitate trade with its neighbors Nigeria, Niger, Burkina Faso and Togo.

A pilot project funded by the United Nations Environment Program (UNEP) revealed that in 40 years, the coast to the east of Cotonou had retreated by 400 meters.

Cotonou International Airport provides service to the capitals of the region and to France, as well as the major cities of Benin: Parakou, Kandi, Natitingou, Djougou, and Savé.

[18] The city is a centre for the automotive trade, with European brands being sold from vast open-air parking lots.

It also hosts some of the most prestigious private universities in Africa which includes: The Office de Radiodiffusion et Télévision du Bénin (ORTB) — the national television and radio operator — is based in Cotonou.