- Oval
- Ormsby
- Oakland
- Oniontown
- Osborn
- Osgood
- Oak Grove
- Oak Grove Trailer Park
- Oak Lane
- Oak Lane Manor
- Oak Park
- Oak Summit
- Oak Wood East
- Oaklane
- Oakwood at Plymouth
- Obelisk
- Olde Village
- Orchard Courts
- Orvilla
- Oxford Manor
- Oak Grove
- Ottawa
- Old Sow Island
- Oak Park
- Oaklyn
- Otto
- Overlook
- Oakgrove
- Old Ferry
- Olney