Assa (Arabic: آسا) is a small town in southern Morocco, in the Assa-Zag province of the Guelmim-Oued Noun region, about 100 kilometres (62 mi) south-east of Guelmim and about 300 kilometres (190 mi) south-west of Foum Zguid. It lies in a desert area north of the Jbel Ouarkziz and is part of the Sahrawi-inhabited southern region of Morocco. The Draa River lies to its south, and the N12 highway crosses the town.

In the 2012 census Assa had a population of 18,367, the largest in its province and sixth largest in the region.