Cities of United States starting with letter O Page 26
- Ortonville (Dallas County, Iowa)
- Ortonville (Ventura County)
- Orum
- Orum (Washington County)
- Orva
- Orvil
- Orvilla
- Orville
- Orville (Henry County, Kentucky)
- Orville (Logan County, West Virginia)
- Orvin
- Orvisburg
- Orwell (Addison County)
- Orwell (Bradford County)
- Orwell (Hodgeman County)
- Orwell (Oswego County)
- Orwig
- Orwood
- Orysa
- Osa
- Osage (Camden County)
- Osage (Carroll County, Arkansas)
- Osage (Coryell County)
- Osage (Henry County, Tennessee)
- Osage (Jefferson County, Ohio)
- Osage Bend
- Osage Bluff
- Osage City (Cole County)
- Osage Heights
- Osage Hills
- Osage Junction
- Osage Mills
- Osaka
- Osaka (Escambia County, Alabama)
- Osanippa
- Osbernville
- Osborn (Butler County, Missouri)
- Osborn (Charleston County)
- Osborn (Floyd County, Kentucky)
- Osborn (Johnson County, Tennessee)
- Osborn (Lake County, Indiana)
- Osborn (Mercer County, Pennsylvania)
- Osborn (Oktibbeha County)
- Osborn (Perry County)
- Osborn (Rock Island County)
- Osborn (Towns County)
- Osborn Corner
- Osborn Corners
- Osborn Crossing
- Osborn Landing