The canton Vallon has 10 communes.
| Code | Name | Population ▼ |
|---|---|---|
| 12090 | Druelle Balsac | 3 187 |
| 12254 | Salles-la-Source | 2 333 |
| 12138 | Marcillac-Vallon | 1 711 |
| 12288 | Valady | 1 610 |
| 12215 | Saint-Christophe-Vallon | 1 186 |
| 12066 | Clairvaux-d'Aveyron | 1 158 |
| 12171 | Nauviale | 577 |
| 12161 | Mouret | 560 |
| 12165 | Muret-le-Château | 350 |
| 12193 | Pruines | 289 |