- Oak Park
- Oak Grove Mobile Home Park
- Otto
- Otter Creek
- Onigum
- Oshawa
- Oakwood Court
- O J Mathison Mobile Home Park
- Oskenonton Island
- Oreland
- Orchard Garden
- Oslo
- Olson's Mobile Park
- Ostrander Mobile Home Park
- Old Frontenac
- Oak Knoll
- Oak Terrace
- Oxboro
- Oak Grove
- Oakdale
- Odessa
- Odin
- Ogema
- Olivia
- Orono
- Ortonville
- Oslo
- Ostrander
- Otsego
- Onstad Trailer Park