Miasta Stany Zjednoczone, począwszy od litery O Strona 16
- Oasis (Sierra County)
- Orlando (Logan County, Oklahoma)
- Okolona (Clark County, Arkansas)
- Oak Ridge (Morehouse Parish)
- Oak Ridge (Cooke County)
- Onton
- Old Bennington
- Oswayo
- Oatman
- Odessa (Big Stone County)
- Ohlman
- Osnabrock
- Otter Creek
- Oldham
- Ormsby
- Odessa (Buffalo County)
- Orason Acres Colonia
- Oaks (Clay County)
- Olean (Miller County, Missouri)
- Octavia
- Oelrichs
- Orme
- Otterville (Jersey County)
- Oakvale
- Oriska
- Omaha (Stewart County)
- Orient (Ferry County)
- Ohiowa
- Olmitz
- Oxbow (Jefferson County, New York)
- Oto
- Old Ripley
- Old Agency
- Odin (Watonwan County)
- O'Brien
- Oberon
- Oyens
- Odin (Barton County)
- Onward
- Opal (Lincoln County, Wyoming)
- Orviston
- Oakland Park (Jasper County)
- Orrum
- Orchard (Morgan County, Colorado)
- Otway
- Oldtown (Allegany County)
- Oyehut
- Opheim
- Old Appleton
- Ozan