Municipality |
County |
Senate |
O |
Oakfield | Aroostook | District 34 |
| Oakland | Kennebec | District 24 | |
| Ocean Park | York | District 05 | |
| Ogunquit | York | District 01 | |
| Olamon | Penobscot | District 30 | |
| Old Orchard Beach | York | District 05 | |
| Old Town | Penobscot | District 30 |
| Oquossoc | Franklin | District 18 | |
| Orient | Aroostook | District 34 | |
| Orland | Hancock | District 31 | |
| Orneville Twp | Piscataquis | District 27 | |
| Orono | Penobscot | District 30 | |
| Orrington | Penobscot | District 31 | |
| Orrs Island | Cumberland | District 10 | |
| Osborn | Hancock | District 29 | |
| Otis | Hancock | District 31 | |
| Otisfield | Oxford | District 13 | |
| Otter Creek | Hancock | District 28 | |
| Owl's Head | Knox | District 22 | |
| Oxbow Plt | Aroostook | District 34 | |
| Oxford | Oxford | District 13 |