The main cities in the arrondissement, with more than 20,000 inhabitants in 2019, are Montpellier (295,542 inhabitants), Sète (43,858 inhabitants), Lunel (26,385 inhabitants), Frontignan (23,028 inhabitants) and Castelnau-le-Lez (22,534 inhabitants).[4]
The arrondissement of Montpellier was created in 1800.[5] In 2009 it lost the three cantons of Aniane, Ganges and Saint-Martin-de-Londres to the arrondissement of Lodève.[6] At the January 2017 reorganisation of the arrondissements of Hérault, it gained one commune from the arrondissement of Béziers, and it lost 26 communes to the arrondissement of Lodève.[7]
As a result of the reorganisation of the cantons of France which came into effect in 2015, the borders of the cantons are no longer related to the borders of the arrondissements. The cantons of the arrondissement of Montpellier were, as of January 2015:[8]