The Hoanib is one of the 12 ephemeral seasonal rivers in the west of Namibia, where it was the border between northern Damaraland and Kaokoland. Its length is 270 km.

With the low population density, the oasis character of the river valley and the relatively high wildlife population of Hoanib, together with the Hoarusib its valley is one of the last true wilderness areas in Namibia, one of the last settlements of desert elephants and shows strong wind and water eroded and weathered stone deposits (up to 10 m height). Inflows of Hoanib are Ombonde, Ganamub, Mudorib and Tsuxab.