Adrar (Arabic: ولاية أدرار, Berber languages: ⴰⴷⵔⴰⵔ) is a province (wilaya) in southwestern Algeria, named after its capital Adrar. It is the second-largest province, with an area of 424,948 km², roughly the size of the US state of California. It had 402,197 inhabitants at the 2008 population census.
It is bordered by five other wilayas: to the west by Tindouf; to the north by Béchar and El Bayadh; to the east by Ghardaïa and Tamanrasset. To the south, it is bordered by Mauritania and Mali.
Adrar is composed of three natural and cultural regions: Touat (Adrar, Zaouiet Kounta), Gourara (Aougrout, Timimoune) and Tidikelt (Aoulef), and 299 ksour.
The province of Adrar is located in south-west Algeria.