Cities of United States starting with letter O Page 3
- Owatonna
- Ossining
- Ottumwa
- Otsego County (Michigan)
- Ohio County (Kentucky)
- Old Bridge
- Osceola County (Michigan)
- Oak Ridge (Orange County)
- Overton County
- Oak Harbor
- Ogemaw County
- Owen County
- Oxford
- Okemos
- Oxford (Calhoun County, Alabama)
- Oakdale (Stanislaus County)
- Oregon (Lucas County)
- Orange County (Indiana)
- Orchards
- Oxford (Lafayette County)
- Otero County (Colorado)
- Ottawa
- Orange (Orange County)
- Oswego (Oswego County)
- Ojus
- Ozark
- Onalaska
- Oxon Hill
- Orinda
- Ocean Springs
- Okolona
- Opelousas
- Oak Grove
- Osage County (Kansas)
- Ocean Acres
- Overland
- Oconomowoc
- Otoe County
- Oroville
- Opa-locka
- Owosso
- Ozark
- Oglethorpe County
- Olean
- O'Brien County
- Orangeburg
- Orange (New Haven County)
- Oneonta
- Osage County (Missouri)
- Oak Park (Ventura County)