The Erg Iguidi (Arabic: عرق إقيدي), is a large erg in the area of Tindouf in southwestern Algeria, extending into northern Mali and Mauritania.

[1] The Erg Iguidi is a sandy desert with a clear pattern of narrow linear dunes stretching for a length of 400 km.

Part of the greater Sahara, it is located in its northwestern region and is characterized by Harmattan withering winds.

Groundwater is especially abundant towards the north-eastern edge of the Erg Iguidi.

[2] There are patches of seasonal vegetation with grasses and shrubs and in the summer the desert is used as a pasturage area.