| - | - | Skyway Manor Airport | Pearland | |
| - | - | Skywest Airpark | Mobile | |
| - | - | Skywest Inc | Midland | |
| - | - | Slate Creek | Slate Creek | |
| - | - | Slater Memorial | Slater | |
| - | - | Slatington Airport | Slatington | |
| - | - | Slaton Municipal | Slaton | |
| NSL | - | Slayton Municipal Airport | Slayton | |
| - | - | Sleepy Eye Municipal | Sleepy Eye | |
| - | KASD | Slidell | Slidell | |
| - | - | Smiley Creek | Galena | |
| - | - | Smith | Macomb | |
| - | KMRH | Smith | Beaufort | |
| SCJ | - | Smith Cove Airport | Smith Cove | |
| SLG | KSLG | Smith Field | Siloam Springs | |
| SMD | KSMD | Smith Field | Fort Wayne | |
| - | KLRY | Smith Memorial | Harrisonville | |
| - | - | Smith Mountain Lake | Moneta | |
| - | - | Smith Prairie | Prairie | |
| - | - | Smithville Municipal | Smithville | |
| - | - | Smithville Municipal Airport | Smithville | |
| - | - | Smoketown | Smoketown | |
| - | - | Smyrna | Smyrna | |
| - | - | Snyder | Snyder | |
| ONM | KONM | Socorro Airport | Socorro | |
| - | - | Solberg-Hunterdon | Readington | |
| - | - | Soldier Bar Usfs | Soldier Bar | |
| SXQ | PASX | Soldotna Airport | Soldotna | |
| SOL | - | Solomon State Field | Solomon | |
| - | KOLG | Solon Springs Municipal | Solon Springs | |
| - | KSMQ | Somerset | Somerville | |
| - | - | Somerset Co | Somerset | |
| - | - | Somerville | Ada | |
| - | - | Sonoma Skypark | Sonoma | |
| - | - | Sonoma Valley Airport | Schellville-Sonoma | |
| - | - | Sonora Municipal | Sonora | |
| - | - | South Albany | South Bethlehem | |
| GEY | KGEY | South Big Horn County Airport | Greybull | |
| - | - | South Co Of Santa Clara Co | San Martin | |
| - | - | South Fulton | Palmetto | |
| - | - | South Haven Area Regional | South Haven | |
| - | - | South Lafourche | Galliano | |
| - | - | South Lakeland Airport | Mulberry | |
| - | KSGS | South St Paul Municipal Airport | South St Paul | |
| NZW | - | South Weymouth Airport | South Weymouth | |
| - | - | Southard | Bieber | |
| - | - | Southbridge Municipal | Southbridge | |
| - | - | Southeast Greensboro | Greensboro | |
| - | KACJ | Souther | Americus | |
| - | - | Southern Cross | Williamstown | |