The canton Plaintel has 9 communes.
| Code | Name | Population ▼ |
|---|---|---|
| 22171 | Plaintel | 4 602 |
| 22203 | Plœuc-L'Hermitage | 4 103 |
| 22258 | Quessoy | 3 969 |
| 22079 | Hénon | 2 310 |
| 22184 | Plémy | 1 578 |
| 22281 | Saint-Carreuc | 1 576 |
| 22346 | Trédaniel | 906 |
| 22153 | Moncontour | 738 |
| 22009 | Le Bodéo | 186 |