| Code | Name | Region |
|---|---|---|
| USSHJ | Schuyler | NE |
| USSE6 | Schuyler | VA |
| USSV3 | Schuylerville | NY |
| USSKL | Schuylkill | PA |
| USSKU | Schuylkill Haven | PA |
| USH7A | Schuylkill Haven | PA |
| USS77 | Schwenksville | PA |
| USHL9 | Science Hill | KY |
| USS44 | Scio | OR |
| US2SV | Sciotoville | OH |
| USIJC | Scipio Center | NY |
| USSCU | Scituate | MA |
| USSCO | Scobey | MT |
| USSCW | Scobeyville | NJ |
| USXLQ | Scofield | UT |
| USM8S | Scooba | MS |
| USSPJ | Scotch Plains | NJ |
| USSIA | Scotia | CA |
| USSCA | Scappoose | OR |
| USSZX | Scarborough | ME |
| USSCG | Scarsdale | NY |
| USSFT | Schaefferstown | PA |
| USGHK | Schaghticoke | NY |
| USSCX | Schaller | IA |
| USJMH | Schaumburg | IL |
| USSCH | Schenectady | NY |
| USNVU | Schenevus | NY |
| USSCP | Schenley | PA |
| USSVL | Schererville | IN |
| USSRT | Schertz | TX |
| USSID | Schiller Park | IL |
| USHSW | Schleswig | IA |
| USSK5 | Schnecksville | PA |
| USSKN | Schodack Landing | NY |
| USSFW | Schofield | WI |
| USSR8 | Schoharie | NY |
| USSZC | Scholls | OR |
| USOLC | Schoolcraft | MI |
| USSWR | Sawyer | MI |
| USYXS | Sawyer | MN |
| USZFF | Sawyer | OK |
| USS5A | Saxapahaw | NC |
| USXVL | Saxeville | WI |
| USSB2 | Saxonburg | PA |
| USAX2 | Saxton | PA |
| USSYK | Saybrook | CT |
| USSB4 | Saybrook | OH |
| USAYV | Saylesville | RI |
| USYGB | Saylorsburg | PA |
| USYNY | Sayner | WI |