| Code | Name | Region |
|---|---|---|
| USSYW | Seymour | WI |
| USS97 | Shackelefords | VA |
| USS5F | Shacklefords | VA |
| USDGP | Shade Gap | PA |
| USAD2 | Shadeland, Tippecanoe | IN |
| USSZJ | Shady Dale | GA |
| USDYG | Shady Grove | PA |
| USIYP | Shady Point | OK |
| USRYS | Shady Spring | WV |
| USSHY | Shadyside | OH |
| USSF7 | Shafer | MN |
| USMIT | Shafter | CA |
| USSH3 | Shafter, Kern | CA |
| USS2H | Shaftsbury | VT |
| USSHX | Shageluk | AK |
| USXSK | Shaker Heights | OH |
| USSKE | Shakopee | MN |
| USSKK | Shaktoolik | AK |
| USS7V | Severance | CO |
| USSEV | Severn | MD |
| USSVN | Severn | NC |
| USSVJ | Severn | VA |
| USSNR | Severna Park | MD |
| USSXR | Sevier | NC |
| USSVU | Sevierville | TN |
| USZVL | Seville | OH |
| USUOS | Sewanee | TN |
| USSWD | Seward | AK |
| USQSR | Seward | IL |
| USNSR | Seward | NE |
| USSWN | Sewaren | NJ |
| USYSW | Sewell | NJ |
| USS5T | Sewell's Point | VA |
| USEWC | Sewickley | PA |
| USSZK | Seymour | CT |
| USEOU | Seymour | IA |
| USSER | Seymour | IN |
| USSEJ | Seymour | MO |
| USXMI | Seneca | IL |
| USEEC | Seneca | KS |
| USSNE | Seneca | MO |
| USUYP | Seneca | NY |
| USZYC | Seneca | PA |
| USSQW | Seneca | SC |
| USSFS | Seneca Falls | NY |
| USXMJ | Senecaville | OH |
| USSN2 | Senoia | GA |
| USSQF | Sepulveda | CA |
| USSQ5 | Sequatchie | TN |
| USSQV | Sequim | WA |