The Ziz River (Arabic: وادي زيز wadī zīz or نهر زيز nahr zīz) is a river in the south of Morocco and Algeria. It has its source in the High Atlas mountains of Morocco and flows 282 kilometers (175 mi) into the Sahara Desert in Algeria. Although water flow is intermittent along the Ziz riverbed, its watercourse has long been used to facilitate human transit through the mountainous region.

Cities along the Ziz river include Errachidia, Erfoud and Sijilmassa. There is a dam with hydroelectric generating capacity on the Ziz near Errachidia.

Along the Ziz there is typically a common water rights rule, wherein each village and villager is entitled to a fair use and extraction of Ziz waters. Characteristically water is diverted in flatter areas to form a canal that irrigates palm groves and other crops as well as supplies domestic use.

• Sijilmasa, a historically important city founded on the banks of the Ziz river

• Agrawal, Arun; Clark C. Gibson (2001). Communities and the Environment: Ethnicity, Gender. Rutgers University Press. ISBN 0-8135-2914-X. Retrieved May 17, 2009.

32°28′43″N 4°46′10″W / 32.47861°N 4.76944°W / 32.47861; -4.76944