The Roman Catholic Diocese of Ouesso () is a diocese located in the city of Ouésso in the ecclesiastical province of Owando in the Republic of the Congo. The current bishop is Gélase Armel Kema
The diocese of Ouesso was established from the Diocese of Owando on June 6, 1983. Its first bishop was Hervé Itoua.
In 2004, the diocese had six secular priests and three religious priests. There were three male religious, and eighteen female religious. The diocese had 28 parishes.