- Oceana
- Octagon
- Old Fitzhugh
- Ordsburg
- Oakwood
- Old Mount Vinco
- Oak Grove
- Oxford Furnace
- Oak Corner
- Olive
- Olney Corner
- Oak Grove
- Ocala
- Ontario
- Oak Forest
- Oak Hill Estates
- Oakhaven Farms
- Old Coach Hills
- Old Gun
- Otterdale
- Oakshade
- Overlook Heights
- Oak Forest
- Omaha
- Open Fork
- Oakhill
- Orange
- Oakley
- Oakwood Mobile Home Park
- Occupacia