- O'Briens Corner
- Oak Bluffs
- Oak Grove
- Oak Grove Village
- Oak Hill
- Oak Hill Park
- Oak Island
- Oak Island
- Oak Island
- Oak Island
- Oak Rock
- Oakdale
- Oakdale
- Oakdale
- Oakdale
- Oakham
- Oakland
- Oakland Heights
- Oakland Square
- Oakland Vale
- Oaklands
- Ocean Bluff
- Ocean Bluff-Brant Rock
- Ocean Grove
- Ocean Heights
- Ocean View
- Off Rock
- Oklahoma Heights
- Old Bartlemy
- Old Boat Point