The Omo River (Amharic: ኦሞ ወንዝ, romanized: Omo Wenizi; also called Omo-Bottego) 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.

The river basin is famous for its large number of early hominid fossils and archeological findings such as early stone tools, leading to its inclusion on the UNESCO World Heritage List in 1980.