The Canton of Saint-Paul-Trois-Châteaux is a former canton located in the Department of Drôme, in the Arrondissement of Nyons. Its seat (chef-lieu) was the town Saint-Paul-Trois-Châteaux. The canton had 19,749 inhabitants in 2012. It was disbanded following the French canton reorganisation which came into effect in March 2015. It included the following communes:

• Cantons of the Drôme department

44°19′20″N 4°50′23″E / 44.32222°N 4.83972°E / 44.32222; 4.83972