Arrondissement of Riom, (subprefecture: Riom) with 155 communes. The population of the arrondissement was 135,164 in 2016.
Arrondissement of Thiers, (subprefecture: Thiers) with 44 communes. The population of the arrondissement was 56,321 in 2016.
In 1800 the arrondissements of Clermont-Ferrand, Ambert, Issoire, Riom and Thiers were established. The arrondissement of Ambert was disbanded in 1926, and restored in 1942.[4]
The borders of the arrondissements of Puy-de-Dôme were modified in January 2017:[5]
three communes from the arrondissement of Clermont-Ferrand to the arrondissement of Ambert
21 communes from the arrondissement of Clermont-Ferrand to the arrondissement of Issoire
17 communes from the arrondissement of Clermont-Ferrand to the arrondissement of Riom
four communes from the arrondissement of Clermont-Ferrand to the arrondissement of Thiers
one commune from the arrondissement of Riom to the arrondissement of Clermont-Ferrand
three communes from the arrondissement of Thiers to the arrondissement of Riom