The arrondissement of Pontivy was created in 1800.[4] At the January 2017 reorganisation of the arrondissements of Morbihan, it gained 21 communes from the arrondissement of Vannes.[5]
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 Pontivy were, as of January 2015:[6]