| Code | Name | Region |
|---|---|---|
| USS5G | Sturgis | MS |
| USZTI | Sturgis | SD |
| USSRX | Sturtevant | WI |
| USSGT | Stuttgart | AR |
| USVUR | Stuttgart | AR |
| USS9U | Suamico | WI |
| USSB9 | Sublette | KS |
| USSUZ | Sublimity | OR |
| USSQJ | Succasunna | NJ |
| USSUQ | Success | MO |
| USSDU | Sudan | TX |
| USSUR | Sudbury | MA |
| US3SM | Sudlersville | MD |
| USSUJ | Suffern | NY |
| USXLV | Suffield | CT |
| USF7D | Suffield | OH |
| USSUF | Suffolk | VA |
| USHJD | Sugar City | ID |
| USSKX | Sugar Creek | MO |
| USSG6 | Stringtown | OK |
| USTAQ | Strong | AR |
| USSXE | Strong | ME |
| USQGN | Strongstown | PA |
| USSSV | Strongsville | OH |
| USSUD | Stroud | OK |
| USSDG | Stroudsburg | PA |
| USUCT | Strum | WI |
| USTRS | Struthers | OH |
| USKRT | Stryker | OH |
| USYKR | Strykersville | NY |
| USSUA | Stuart | FL |
| USTZT | Stuart | IA |
| USST2 | Stuart | VA |
| USSSW | Stuart Island | WA |
| USTUD | Stuarts Draft | VA |
| USSCY | Studio City | CA |
| USTBI | Sturbridge | MA |
| USSUE | Sturgeon Bay | WI |
| USTUG | Sturgis | KY |
| USAHG | Stratford | NY |
| USZTT | Stratford | OK |
| US3ST | Stratford | TX |
| USTFO | Stratford | WI |
| USSMH | Stratham | NH |
| USSMM | Strathmere | NJ |
| USSMJ | Strathmore | CA |
| USS8V | Strattanville | |
| USST5 | Stratton | OH |
| USTIU | Stratton Mountain | VT |
| USUYY | Straughn | IN |