- Oakland
- Oxford
- Oakfield
- Orient
- Orland
- Otis
- Outer Birch Island
- Outer Goose Island
- Outer Green Island
- Outer Green Island
- Outer Sand Island
- Outer Spectacle Island
- Outer Twin Island
- Oak Hill
- Oak Hill
- Oak Hill
- Oak Hill
- Oak Island
- Oak Island
- Oak Island
- Oak Island
- Oak Island
- Oak Island
- Oak Islands
- Oak Knoll Island
- Oak Ridge
- Oak Terrace
- Oakdale
- Oakes Corner
- Oakwood