Cities of United States starting with letter O
City directory of United States, starting with the letter O, are listed on this page.
- State of Ohio
- Oregon
- State of Oklahoma
- Orange County
- Oakland County
- Orange County (Florida)
- Oklahoma County
- Oklahoma City
- Ocean County
- Onondaga County
- Omaha
- Oakland
- Orange County (New York)
- Orleans Parish
- Osceola County
- Ottawa County
- Orlando
- Oneida County
- Oxnard
- Oxnard Shores
- Okaloosa County
- Onslow County
- Outagamie County
- Overland Park
- Oceanside
- Ontario
- Ouachita Parish
- Olmsted County
- Orange
- Orange County (North Carolina)
- Olathe
- Oswego County
- Ontario County
- Odessa
- Orangeburg County
- Orem
- Ozaukee County
- Ogden
- Orange County (Texas)
- O'Fallon
- Oconee County
- Oshkosh
- Otero County
- Otsego County
- Oldham County
- Oxford County
- Otter Tail County
- Owensboro
- Orland Park
- Oak Lawn