| Code | Name | Region |
|---|---|---|
| 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 |
| USSY2 | Sayre | OK |
| USAYJ | Sayre | PA |
| USXNA | Sayreville | NJ |
| USSYS | Sayville | NY |
| USQJZ | Scales Mound | IL |
| USZVN | Scammon | KS |
| USSCM | Scammon Bay | AK |
| USSC9 | Scanlon | MN |
| USSSM | Sault Sainte Marie | MI |
| USZUN | Saunderstown | RI |
| USJMC | Sausalito | CA |
| US9SN | Sautee Nacoochee | GA |
| USSGE | Savage | MD |
| USXLY | Savage | MN |
| USVGE | Savage | MT |
| USSNQ | Savanna | IL |
| USSAV | Savannah | GA |
| USSA8 | Savannah | MO |
| USXMX | Savannah | NY |
| USSH8 | Savannah | OH |