| SOV | PASO | Seldovia Airport | Seldovia | |
| MTC | KMTC | Selfridge Air National Guard Base | Mount Clemens | |
| SHX | - | Shageluk Airport | Shageluk | |
| SKK | - | Shaktoolik Airport | Shaktoolik | |
| SSC | KSSC | Shaw Air Force Base | Sumter | |
| SBM | KSBM | Sheboygan County Memorial Airport | Sheboygan | |
| SXP | - | Sheldon Sea Plane Base | Sheldon Point | |
| SHD | KSHD | Shenandoah Valley Airport | Staunton | |
| SHR | KSHR | Sheridan Airport | Sheridan | |
| SHH | PASH | Shishmaref Airport | Shishmaref | |
| SAA | KSAA | Shively Field | Saratoga | |
| SOW | KSOW | Show Low Airport | Show Low | |
| SHG | - | Shungnak Airport | Shungnak | |
| SNY | KSNY | Sidney Municipal Airport | Sidney | |
| SUX | KSUX | Sioux Gateway Airport | Sioux City | |
| SIT | PASI | Sitka Airport | Sitka | |
| MVW | KBVS | Skagit Regional Airport | Mount Vernon | |
| SGY | PAGY | Skagway Airport | Skagway | |
| SLQ | PASL | Sleetmute Airport | Sleetmute | |
| ISN | KISN | Sloulin Field International Airport | Williston | |
| INT | KINT | Smith-Reynolds Airport | Winston-Salem | |
| MQY | KMQY | Smyrna Airport | Smyrna | |
| PAE | KPAE | Snohomish County Airport | Everett | |
| STS | KSTS | Sonoma County Airport | Santa Rosa | |
| ELD | KELD | South Arkansas Regional Airport | El Dorado | |
| WSN | - | South Naknek Airport | South Naknek | |
| BRO | KBRO | South Padre Island International Airport | Brownsville | |
| - | KHDO | South Texas Regional Airport at Hondo | Hondo | |
| ISW | KISW | South Wood County Airport | Wisconsin Rapids | |
| VCV | KVCV | Southern California Logistics Airport | Victorville | |
| ABY | KABY | Southwest Georgia Regional Airport | Albany | |
| BEH | KBEH | Southwest Michigan Regional Airport | Benton Harbor | |
| MML | KMML | Southwest Minnesota Regional Airport | Marshall | |
| OTH | KOTH | Southwest Oregon Regional Airport | North Bend | |
| TIX | KTIX | Space Center Executive Airport | Titusville | |
| SVW | PASV | Sparrevohn Air Force Station | Sparrevohn | |
| SPZ | KASG | Springdale Municipal Airport | Springdale | |
| - | PAPB | St George | St George | |
| SPG | KSPG | St Pete-Albert Whitted Airport | Saint Petersburg | |
| UST | KSGJ | St. Augustine Airport | Saint Augustine | |
| STC | KSTC | St. Cloud Municipal Airport | Saint Cloud | |
| STG | - | St. George Island Airport | Saint George Island | |
| CPS | KCPS | St. Louis Downtown Airport | Saint Louis | |
| ALN | KALN | St. Louis Regional Airport | Alton | |
| - | - | St. Michael | St. Michael | |
| SMK | - | St. Michael Airport | Saint Michael | |
| PIE | KPIE | St. Petersburg-Clearwater International Airport | Saint Petersburg | |
| HES | KHRI | State Airport | Hermiston | |
| TBR | KTBR | Statesboro-Bulloch County Airport | Statesboro | |
| SVH | KSVH | Statesville Municipal Airport | Statesville | |