The canton Briec has 18 communes.
| Code | Name | Population ▼ |
|---|---|---|
| 29020 | Briec | 5 816 |
| 29162 | Pleyben | 3 692 |
| 29027 | Châteauneuf-du-Faou | 3 651 |
| 29048 | Edern | 2 186 |
| 29106 | Landrévarzec | 1 882 |
| 29041 | Coray | 1 856 |
| 29062 | Gouézec | 1 111 |
| 29291 | Trégourez | 947 |
| 29107 | Landudal | 930 |
| 29125 | Leuhan | 846 |
| 29110 | Langolen | 836 |
| 29123 | Lennon | 812 |
| 29249 | Saint-Goazec | 739 |
| 29267 | Saint-Thois | 703 |
| 29122 | Laz | 685 |
| 29033 | Le Cloître-Pleyben | 502 |
| 29142 | Lothey | 424 |
| 29115 | Lannédern | 321 |