The canton Riom-ès-Montagnes has 23 communes.
| Code | Name | Population ▼ |
|---|---|---|
| 15162 | Riom-ès-Montagnes | 2 405 |
| 15054 | Condat | 933 |
| 15124 | Menet | 521 |
| 15114 | Marcenat | 508 |
| 15243 | Trizac | 446 |
| 15137 | Moussages | 247 |
| 15185 | Saint-Étienne-de-Chomeil | 241 |
| 15246 | Valette | 236 |
| 15170 | Saint-Amandin | 225 |
| 15009 | Apchon | 177 |
| 15129 | Montboudif | 161 |
| 15015 | Auzers | 159 |
| 15052 | Collandres | 155 |
| 15123 | Méallet | 153 |
| 15116 | Marchastel | 131 |
| 15110 | Lugarde | 117 |
| 15066 | Le Falgoux | 113 |
| 15173 | Saint-Bonnet-de-Condat | 113 |
| 15040 | Chanterelle | 99 |
| 15190 | Saint-Hippolyte | 99 |
| 15218 | Saint-Vincent-de-Salers | 70 |
| 15249 | Le Vaulmier | 60 |
| 15132 | Montgreleix | 31 |