In 1891, a mission led by Alfred Fourneau established a French colonial post at Ouesso, at the confluence of the Sangha and Ngoko rivers.

There were whole periods of quasi-autonomy under the control of local tribal chiefs and also under German colonial rule on a few occasions until 1918, when the town effectively became part of the French Congo.

The meat was transported from Liousesso, a village southwest out Ouésso, and often on logging trucks from Cameroon.

[6] On 27 October 2016, ivory dealer Hamadou Abbo, and his accomplices, Minda Xavier and Gonock Evounanga Edgard, were each sentenced to 5 years in an Ouésso prison.

[10] In 2010, the Parliament of the Republic of the Congo passed a law that gave protection to the country's indigenous pygmy and Baka people and their land.

[11] In April 2007, a South Korean consortium proposed to build a railway to Ouésso from Brazzaville, in exchange for a concession to harvest timber.

[16] In 2023, the Chinese National Development and Reform Commission built the Sanha Bridge and the Ouésso-Pokola Road for Ouésso.