The regional capital is Koulamoutou, a city of approximately 16,000 people.

It is the ninth largest city in Gabon and the home of slightly more than one-third of the provincial population.

Its length runs from the 3 S to 2 N and from 10 E to 11 E. To the south, Ogooué-Lolo borders the Niari Region of the Republic of the Congo.

Domestically, it borders the following provinces: Ogooué-Lolo is divided into 4 departments:[2] The population from 1981 to 1991 lost slightly more than one tenth of the total 1981 population.

The population loss was slower than other provinces in Gabon.