Place
- Ontario--Windsor1
- Oregon--Klamath County1
- Oregon--Morrow County1
- Oregon--Multnomah County1
- Oregon--Polk County1
- Oregon--Sherman County1
- Oregon--Washington County1
- Orono, Minnesota1
- Osceola Township1
- Oslo1
- Osseo, Minnesota1
- Pachmarhi1
- Palmyra Township1
- Paxton Township1
- Pennsylvania--Cambria County1
- Pennsylvania--Erie--Erie County1
- Pennsylvania--Franklin County1
- Pennsylvania--Lakawanna County1
- Pennsylvania--Lehigh County1
- Pennsylvania--Northampton County1