It is subdivided into nine communes, each centred at one of the principal towns: Adjarra, Adjohoun, Aguégués, Akpro-Missérété, Avrankou, Bonou, Dangbo, Porto-Novo and Sèmè-Kpodji.

It is located in a coastal area that has interconnected lakes and lagoons and elongated coastlines with wide marshes.

The southern regions of Benin receive two spells of rain from March to July and September to November, while the northern regions of the country receive one season of rainfall from May to September.

Petroleum was discovered in the 1960s in offshore areas, while titanium, low quality iron ore, ilmenite and chromite are the major minerals.

[5] The main ethnolinguistic groups in the department include the Ayizo, Ede, Fon, Gun, Phla (or 'Xwla'), Tofin and Yoruba.

Ouémé is subdivided into nine communes, each centered at one of the principal towns: Adjarra, Adjohoun, Aguégués, Akpro-Missérété, Avrankou, Bonou, Dangbo, Porto-Novo and Sèmè-Kpodji.

A law passed in 1999 transformed the sous-prefectures, the lowest level of territorial administration, into local governments.

[9] Municipalities and communal councils have elected representatives who manage the administration of the regions.