The Iullemmeden Basin is a major sub-Saharan inland basin in West Africa, extending about 1000 km north to south and 800 km east to west. It covers western Niger and portions of Algeria, Mali, Benin and Nigeria. It is named after the Iullemmeden, a federation of Tuareg people who live in the central region of Niger. Its geographic range is largely coincident with the Azawagh region.