| Locality | Post Code |
|---|---|
| Callensburg, Clarion | 16213 |
| Clarion, Clarion | 16214 |
| Climax, Clarion | 16242 |
| Cooksburg, Clarion | 16217 |
| Corsica, Clarion | 15829 |
| Cranberry, Clarion | 16319 |
| Crown, Clarion | 16220 |
| Curllsville, Clarion | 16221 |
| East Brady, Clarion | 16028 |
| Emlenton, Clarion | 16373 |
| Fairmount City, Clarion | 16224 |
| Fisher, Clarion | 16225 |
| Foxburg, Clarion | 16036 |
| Fryburg, Clarion | 16326 |
| Hawthorn, Clarion | 16230 |
| Huey, Clarion | 16248 |
| Knox, Clarion | 16232 |
| Kossuth, Clarion | 16331 |
| Lamartine, Clarion | 16375 |
| Leeper, Clarion | 16233 |
| Lickingville, Clarion | 16332 |
| Limestone, Clarion | 16234 |
| Lucinda, Clarion | 16235 |
| Marble, Clarion | 16334 |
| Mayport, Clarion | 16240 |
| New Bethlehem, Clarion | 16242 |