O
- Oak Alley
- Oakdale
- Oak Forest
- Oak Grove
- Oak Grove
- Oak Hill
- Oak Hills Place
- Oakland
- Oakland
- Oak Landing
- Oaklawn
- Oak Lawn
- Oakley Landing
- Oaknolia
- Oak Ridge
- Oak Ridge Park
- Oaks
- Oakville
- Oberlin
- Odenburg
- Odra
- Oil City
- Okaloosa
- Oklahoma
- Okland
- Old Athens
- Oldfield
- Old Jefferson
- Old Quarantine Station
- Olive Branch
- Olivier
- Olla
- Ollie
- Omega
- Omega
- O'Neal Place
- Oneida
- Opelousas
- Oretta
- Oscar
- Osceola
- Osceola
- Ossun
- Ostrica
- Otis
- Ouachita City
- Owens
- Oxbow
- Oxford