Sokoto River, river in northwestern Nigeria, rising just south of Funtua on the northern plateau. It flows northwestward in a wide arc for 200 miles (320 km) to Sokoto town, west of which the Rima River joins it in its lower course to its confluence with the Niger River east of Illo. The alluvial valley and plains formed by the Sokoto River are extensively cultivated; peanuts (groundnuts), cotton, tobacco, swamp rice, onions, sugarcane, and indigo are grown. Several irrigation projects have been introduced to promote year-round farming along the river. The Sokoto River serves as an important waterway for the Hausa, Dakarki, and Zabarma peoples.