Largentière is a subprefecture and commune of the Ardèche department in the Auvergne-Rhône-Alpes region in Southern France. It is located in the narrow valley of the Ligne, approximately 10 km southwest of Aubenas. With a population of 1,573 as of 2020, Largentière is the second-least populated subprefecture in France after Castellane in Alpes-de-Haute-Provence.