Miasta Stany Zjednoczone, począwszy od litery O Strona 7
- Oakwood (Cuyahoga County)
- Orrington
- Osage
- Odenville
- Old Mystic
- Ohioville
- Omro
- Ovilla
- Oak Valley
- Oxford (Oakland County)
- Ocilla
- Oakwood (Newton County)
- Ocean Grove
- Orange (Cuyahoga County)
- Ossian
- Olney (Young County)
- Orchard Park
- Oliver Springs
- Ozona
- Okemah
- Oakridge
- Oxoboxo River
- Orofino
- Orchard City
- Orwigsburg
- Oak Ridge North
- Onawa
- Osage City
- Osterville
- Oconto Falls
- Oostburg
- Oakhurst (Madera County)
- Orchidlands Estates
- Ocean Grove (Bristol County)
- Oak Point
- Oak Harbor (Ottawa County)
- Oak Trail Shores
- Okolona (Chickasaw County)
- Owensville
- Oakland (Kennebec County)
- Osceola (Polk County)
- Overton
- Okanogan
- Oakland (Orange County)
- Oliver
- Olivia
- Osceola (Saint Joseph County)
- Old Orchard
- Osseo
- Oakland City