Castellane is a commune located in the Alpes-de-Haute-Provence department within the Provence-Alpes-Côte d'Azur region of southeastern France. It serves as a subprefecture for its respective area.
As of 2023, the commune has a population of 1,472 residents. It holds the distinction of being the second-least populated subprefecture in France, following Largentière in the Ardèche department.