In 1800 the arrondissements of Foix, Pamiers and Saint-Girons were established. The arrondissement of Pamiers was disbanded in 1926, and restored in 1942.[3]
The borders of the arrondissements of Ariège were modified in January 2017:[4]
21 communes from the arrondissement of Foix to the arrondissement of Pamiers
13 communes from the arrondissement of Foix to the arrondissement of Saint-Girons
18 communes from the arrondissement of Pamiers to the arrondissement of Foix
27 communes from the arrondissement of Pamiers to the arrondissement of Saint-Girons