Istres is a commune located in southern France within the Provence-Alpes-Côte d'Azur region. It is situated in the Bouches-du-Rhône department and lies approximately 60 km (38 mi) northwest of Marseille.
The town serves as a subprefecture of the Bouches-du-Rhône department. It is positioned in the southern portion of the country, characterized by its administrative role within the regional infrastructure.