| Code | Name | Region |
|---|---|---|
| USRAJ | Rotterdam | NY |
| USRJN | Rotterdam Junction | NY |
| USRTD | Rotunda | FL |
| USRUC | Round Lake | IL |
| USRL2 | Round Lake | MN |
| USR9T | Roseto | PA |
| USRJT | Roseton | NY |
| USRVC | Roseville | CA |
| USRSV | Roseville | MI |
| USRVE | Roseville | MN |
| USRV9 | Roseville | NC |
| USROS | Roseville | OH |
| USRHQ | Rosharon | TX |
| USOSO | Rosholt | SD |
| USR2T | Rosholt | WI |
| USRO9 | Rosiclaire | IL |
| USRSK | Rosiclare | IL |
| USRZD | Roslindale | MA |
| USYL8 | Roslyn | NY |
| USRYN | Roslyn Heights | NY |
| USRS7 | Rosman | NC |
| USRZO | Ross | CA |
| USRS4 | Ross | OH |
| USR8G | Rossburg | OH |
| USRR2 | Rosser | TX |
| USROZ | Rosedale | NJ |
| USRDQ | Rosedale | NY |
| USXRL | Roseland | LA |
| USRLB | Roseland | NJ |
| USRJZ | Roseland | VA |
| USOEW | Roselawn | IN |
| USRLL | Roselle | IL |
| USRLE | Roselle | NJ |
| USZH2 | Roselle Park | NJ |
| USYFM | Rosemary Beach | FL |
| USRFS | Rosemead | CA |
| USRSI | Rosemont | IL |
| USQRM | Rosemont | NJ |
| USROP | Rosemont | PA |
| USRMM | Rosemount | MN |
| USRSG | Rosenberg | TX |
| USOJE | Rosendale | NY |
| USROD | Rosendale | WI |
| USRON | Rosenhayn | NJ |
| USRZP | Rosepine | LA |
| USRSQ | Roscoe | IL |
| USR5C | Roscoe | NY |
| USUOE | Roscoe | TX |
| USRCQ | Roscommon | MI |
| USRB9 | Rose Bud | AR |