- Obretch Estates
- Oklahoma
- Old Home Estates
- Olde Oak Run
- Olde Washington Valley
- Omar Acres
- Otterdale Mill
- Ottersdale
- Oak Estates
- Oak Hill Estates
- Oak Knolls
- Oakland Acres
- Oakland Estates
- Oakwood
- Oakwood
- Old Sycamore Estates
- Opossum Island
- Oak Acres
- Oak Orchard
- Oak Park
- Oakridge
- Oceola Estates
- Olacin
- Old Orchard Estates
- Oldfield
- Olive
- Overbrook
- O'Donnell Heights
- Oaklee
- Old Town