| Zipcode | Community | City | State | Metro Area |
|---|---|---|---|---|
| 06373 | Oneco | Oneco | Connecticut | Worcester MA-CT |
| 22485 | Owens | King george | Virginia | |
| 23417 | Onancock | Onancock | Virginia | |
| 26431 | Owings | Shinnston | West Virginia | Clarksburg WV |
| 26886 | Onego | Onego | West Virginia | |
| 31775 | Omega | Omega | Georgia | Tifton GA |
| 34264 | Oneco | Oneco | Florida | North Port-Sarasota-Bradenton FL |
| 36467 | Onycha | Opp | Alabama | |
| 51045 | Oyens | Oyens | Iowa | Sioux City IA-NE-SD |
| 57466 | Onaka | Onaka | South Dakota | |
| 57767 | Owanka | Owanka | South Dakota | Rapid City SD |
| 61060 | Oneco | Orangeville | Illinois | Freeport IL |
| 62555 | Owaneco | Owaneco | Illinois | Taylorville IL |
| 62849 | Omega | Iuka | Illinois | Centralia IL |
| 66521 | Onaga | Onaga | Kansas | Manhattan KS |
| 68452 | Ong | Ong | Nebraska | |
| 71276 | Omega | Sondheimer | Louisiana | |
| 73764 | Omega | Omega | Oklahoma | |
| 87829 | Omega | Quemado | New Mexico | |
| 93255 | Onyx | Onyx | California | Bakersfield CA |
| 98841 | Omak | Omak | Washington | |