The Omo River in southern Ethiopia is the largest Ethiopian river outside the Nile Basin. Its course is entirely contained within the boundaries of Ethiopia, and it empties into Lake Turkana on the border with Kenya. The river is the principal stream of an endorheic drainage basin, the Turkana Basin.

Lake Turkana is a saline lake in the Kenyan Rift Valley, in northern Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake. By volume it is the world's fourth-largest salt lake after the Caspian Sea, Issyk-Kul, and Lake Van, and among all lakes it ranks 24th.