Cities in United States ( 10,163 )
- Orlovista
- Ormond Beach
- Ormond-by-the-Sea
- Oro Valley
- Orofino
- Orono, Maine
- Orono, Minnesota
- Orosi, California
- Oroville, California
- Oroville East
- Orrington
- Orrville, Ohio
- Orting
- Orwigsburg
- Osage Beach
- Osage City
- Osage, Iowa
- Osawatomie, Kansas
- Osceola, Arkansas
- Osceola, Iowa
- Osceola, Wisconsin
- Oshkosh, Wisconsin
- Oskaloosa, Iowa
- Osprey, Florida
- Ossian, Indiana
- Ossining (village), New York
- Ossipee
- Osterville
- Oswego, Illinois
- Oswego, New York
- Othello, Washington
- Otis Orchards
- Otsego, Michigan
- Otsego, Minnesota
- Ottawa Hills
- Ottawa, Illinois