| Code | Name | Region |
|---|---|---|
| USRMO | Romeo | MI |
| USROI | Romeoville | IL |
| USZH7 | Romeville | LA |
| USZYZ | Romney | IN |
| USOMD | Romoland | CA |
| USRQJ | Roebling | NJ |
| USRQB | Roebuck | SC |
| USREJ | Roeland Park | KS |
| USRFF | Roff | OK |
| USROG | Rogers | AR |
| USRGS | Rogers | CT |
| USRJM | Rogers | MN |
| USZQ2 | Rogers | OH |
| USRGQ | Rogers | TX |
| USRCY | Rogers City | MI |
| USRH2 | Rogers Haven | DE |
| USOEI | Rogersville | AL |
| USRVZ | Rogersville | MO |
| USRGV | Rogersville | TN |
| USRJQ | Roggen | CO |
| USRGU | Rogue River | OR |
| USRFH | Rohnert Park | CA |
| USOLK | Roland | OK |
| USRVF | Rolesville | NC |
| US3IX | Roll | AZ |
| USKWE | Rockwell | NC |
| USRY3 | Rockwell City | IA |
| USKOO | Rockwood | IL |
| USR8W | Rockwood | ME |
| USRW2 | Rockwood | MI |
| USRQO | Rockwood | OR |
| USRWU | Rockwood | PA |
| USRKW | Rockwood | TN |
| USRYF | Rocky Face | GA |
| USRKF | Rocky Ford | CO |
| USROK | Rocky Hill | CT |
| USRWI | Rocky Mount | NC |
| USROV | Rocky Mount | VA |
| USRCP | Rocky Point | NC |
| USRKY | Rocky River | OH |
| USDTK | Rodanthe | NC |
| USRD4 | Rodeo | CA |
| USRQE | Rodeo | NM |
| USREF | Roderfield | WV |
| USR9E | Roe | AR |
| USRQP | Rockport | IN |
| USJRT | Rockport | MA |
| USRP3 | Rockport | ME |
| USRC4 | Rockport | MO |
| USRKO | Rockport | NJ |