| Code | Name | Region |
|---|---|---|
| USAE5 | Swansea | MA |
| USSS5 | Swansea | SC |
| USSWQ | Swanton | OH |
| USSWA | Swanton | VT |
| USS3V | Swanville | MN |
| USSW5 | Swanzey | NH |
| USXWR | Swarthmore/philadelphia | PA |
| USSXZ | Swartz Creek | MI |
| USSW7 | Swatara | PA |
| USSDS | Swedesboro | NJ |
| USDXU | Sweeny | TX |
| USSWG | Sweet Grass | MT |
| USHOE | Sweet Home | OR |
| USSS9 | Sweet Springs | MO |
| USAAJ | Sweetwater | FL |
| USWW8 | Sweetwater | OK |
| USWWE | Sweetwater | TN |
| USSWW | Sweetwater | TX |
| USSWZ | Swepsonville | NC |
| USXSN | Swifton | AR |
| USZIJ | Sutherlin | VA |
| USSMS | Sutter | CA |
| USXXK | Sutter Creek | CA |
| USSXU | Sutton | AK |
| USTON | Sutton | MA |
| USS55 | Sutton | NE |
| US8UT | Sutton | NH |
| USVMY | Sutton | VT |
| USSUP | Sutton | WV |
| USZYY | Suttons Bay | MI |
| USSVG | Suwanee | GA |
| USS8E | Suwannee | FL |
| USSWJ | Swainsboro | GA |
| USUSW | Swampscott | MA |
| US6SL | Swan Lake | NY |
| USSQ2 | Swan Quarter | NC |
| USVXA | Swan Valley | ID |
| USSNO | Swannanoa | NC |
| USIS9 | Swans Island | ME |
| USSW6 | Swansea | IL |
| USUIQ | Suquamish | WA |
| USUIY | Surf City | NC |
| USSC5 | Surf City | NJ |
| USFUF | Surfside | FL |
| USFBC | Surfside Beach | SC |
| USSGO | Surgoinsville | TN |
| USSGZ | Suring | WI |
| USURS | Surprise | AZ |
| USRRU | Surrency | GA |
| US8RR | Surry | ME |