Debdeb is a town and commune in In Amenas District, Illizi Province, Algeria.

Debdeb lies at an altitude of 345 metres (1,132 ft) near the northern edge of the Hamada de Tinrhert, a large rocky area of the Sahara around the border of Algeria and Libya.

The Grand Erg Oriental, a vast area of sand dunes, lies to the north.

Debdeb has a hot desert climate (Köppen climate classification BWh), with extremely hot summers and mild winters, and very little precipitation throughout the year.

Debdeb is on the national highway N53, which leads north to Ghadames (in Libya) and south to In Amenas.