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.

[1] It was disbanded following the French canton reorganisation which came into effect in March 2015.

It included the following communes:[1]