Cities of United States starting with letter O Page 6
- Okeechobee
- Ocean Shores
- Ocean City (Okaloosa County)
- Old Bethpage
- Orange Beach
- Odessa (Lafayette County, Missouri)
- Oak Park (Clark County, Indiana)
- Orchard Homes
- Olyphant
- Oxford (Chester County)
- Olympia Fields
- Ocean Bluff-Brant Rock
- Osceola (Clarke County, Iowa)
- Omak
- Owsley County
- Ogallala
- Orange (Orange County)
- Old Westbury
- Ossipee
- Offutt Air Force Base
- Orangeburg (Rockland County)
- Obetz
- Oak Hill (Davidson County)
- Ottawa Hills
- Oconto
- Ottawa (Putnam County)
- Osawatomie
- Ouray County
- Oak Grove (Washington County)
- Okauchee Lake
- Orangetree
- Osage Beach
- Oak Park Heights
- Oneida County (Idaho)
- Oak View
- Oaklyn
- Orange (Franklin County, Massachusetts)
- Oakhurst
- Oakwood (Hall County)
- Otsego (Allegan County)
- Owego
- Osborne County
- Olivarez
- Oglesby
- Oak Bluffs
- Oneida (Scott County)
- Oregon (Ogle County)
- O'Neill
- Oracle
- Ozark (Franklin County, Arkansas)