The Ubangi River (also Oubangi) is a major tributary of the Congo River in central Africa. It is considered to begin at the junction of the Bomu and Uele Rivers, flows west for about 350 km, then bends to the southwest, passes through Bangui, then flows south for another 500 km to the Congo.

From its start to 100 km below Bangui, the Ubangi defines the boundary between the Central African Republic and the Democratic Republic of the Congo, thereafter it flows within Congo.