| S7 Airlines | S7 | SBI | 421 |
| Saak-Gem Air Company | SVL | ||
| Saber Aviation | SBR | ||
| Sabre Airways | TJ | SBE | |
| SADELCA - Sociedad Aerea del Caqueta | SDK | ||
| SAETA-Soc.Ecuatoriana de Transp.Aereos | EH | SET | 156 |
| Safair | FA | SFR | 640 |
| Safi Airways | 4Q | SFW | |
| Safiran | SFN | ||
| Saha Airlines | IRZ | ||
| Sahara Airlines | S2 | SHD | 705 |
| SAHSA-Servicios Aereo de Honduras | SH | SHA | 274 |
| Sakha Avia | K7 | IKT | 840 |
| Sakhalin Air Services | |||
| Sakhavia Trans | SVT | ||
| Salpa Sudan | SLP | ||
| Samara Airlines | E5 | BRZ | 906 |
| Samarkand Airways | C7 | UZS | 732 |
| San Cargo Kazakhstan | S3 | SND | |
| SAN Servicios Aereos Nacionales | WB | SAN | 739 |
| SANSA Servicios Aereos Nacionales | RZ | LRS | 503 |
| Santa Barbara Airlines Cargo | S3 | BBR | 249 |
| Sapphire Aviation | SPP | ||
| Saratov Aviation Division | 6W | SOV | 026 |
| Saro Airlines | UF | SRO | |
| SAS Braathens ASA | SK | CNO | |
| SAS-Scandinavian Airlines System | SK | SAS | 117 |
| SAT Airlines | HZ | SHU | 598 |
| SATA - Air Açores | SP | SAT | 737 |
| SATA International | S4 | RZO | 331 |
| Satena | ZT | NSE | |
| Saudi Arabian Airlines | SV | SVA | 065 |
| Sayakhat Air Company | W7 | SAH | 271 |
| SCAT Air | DV | VSV | |
| Schreiner Airways | AW | SCH | 405 |
| Scibe Airlift | ZM | SBZ | 939 |
| Scorpion Air | SPN | ||
| Seagle Air | CGL | ||
| Seagreen Air Transport | ESA | ||
| Sempati Air | SG | SSR | 821 |
| Servivensa-Empresa Servicios Avensa | VC | SVV | 985 |
| SETRA - Servicio de Transporte Aereo | SVI | ||
| Shabair | SS | SHB | |
| Shaheen Air Cargo | SEE | 587 | |
| Shaheen Air International | NL | SAI | 740 |
| Shandong Airlines | SC | CDG | 324 |
| Shanghai Airlines | FM | CSH | 774 |
| Shanxi Airlines | 8C | CXI | |
| Shenzhen Airlines | 4G | CSZ | 479 |
| Shenzhen Donghai Airlines | J5 | EPA | |
| Shorouk Air | 7Q | SHK | 273 |
| Shuswap Air | 3S | SFC | |
| Sibavia | 5M | SIB | 842 |
| Sichuan Airlines | 3U | CSC | 876 |
| Siem Reap Airways International | FT | SRH | |
| Sierra National Airlines | LJ | SLA | 690 |
| Sierra Pacific Airlines | SI | SPA | |
| Silk Way Airlines | ZP | AZQ | 463 |
| SilkAir | MI | SLK | 629 |
| Silver Bird Charterflug | |||
| Silverjet Cargo/Flyjet | Y7 | FJE | 362 |
| Simba Air Cargo | SMB | ||
| Simurg | JRP | ||
| Singapore Airlines | SQ | SIA | |
| Singapore Airlines Cargo | SQ | SQC | 618 |
| Skoda Engineering Air Transport | SOA | ||
| Sky Air Cargo Services | NJA | ||
| Sky Airlines | SHY | ||
| Sky Cabs | 2E | SCB | 602 |
| Sky Express | G3 | SEH | |
| Sky Way Enterprises | SKZ | ||
| Sky West Airlines | OO | SKW | 302 |
| Skyair Cargo | TAW | ||
| Skybus | SX | SKB | |
| Skydrift Ltd | SDL | ||
| SkyEurope Airlines | 5P | HSK | |
| Skyjet Brasil | SKA | 062 | |
| Skyking Airlines | RU | SKI | 025 |
| Skyline NEPC | D2 | DAM | 059 |
| SkyLink Aviation | SKK | ||
| Skymark Airlines | BC | SKY | |
| Skynet Airlines | SI | SIH | 597 |
| Skynet Asia Airways | 6J | SNJ | |
| Skyservice | SSV | 884 | |
| SkyTeam Luftfahtunternehmen | XST | ||
| Skyward Aviation | K9 | SGK | 470 |
| Skyways AB | JZ | SKX | 752 |
| Skywest Airlines | XR | OZW | 674 |
| Skywind Air Company | AZH | ||
| Slovak Airlines | 6Q | SLL | 921 |
| SNAS Worldwide Express | RSE | 952 | |
| Sobelair | SLR | 644 | |
| Sochispetsavia Air Company | |||
| Sociedad Aeronautica de Medellin (SAM) | MM | SAM | 334 |
| Societe Nouvelle Europe Aero Service | EY | EYT | |
| Société d´exflatatim Aeropostale | |||
| Solar Wind | |||
| Solomon Airlines | IE | SOL | 193 |
| Somali Airlines | SOM | ||
| Sonmez Airlines | SMZ | ||
| Sosoliso Airlines | OSL | ||
| South African Airways Cargo | SA | SAA | 083 |
| South African Express Airways | XZ | EXY | 83 |
| South Airlines | YG | OTL | |
| South American Airways | |||
| South Central Air | XE | SCA | 301 |
| South Pacific Island Airways | SPI | ||
| Southeast Airways | SEA | ||
| Southend Cargo Airlines | SYZ | 751 | |
| Southern Air | SJ | SJM | 351 |
| Southern Air | SJ | SJM | 351 |
| Southern Air | 9S | SOO | |
| Southern Aviation | STV | ||
| Southern Winds | A4 | SWD | 242 |
| Southwest Airlines | WN | SWA | 526 |
| Spair Air Transport | PAR | ||
| Spanair | JK | JKK | 680 |
| Special Cargo Airlines | C7 | SCI | 424 |
| SpiceJet | SG | SEJ | |
| Spirit Airlines | NK | SWG | 487 |
| Spring Airlines | 9S | CQH | 089 |
| Srilankan Airlines | UL | ALK | 603 |
| Sriwijaya Air | SJY | ||
| STA Trans African Airlines | T8 | STA | |
| STAF Airlines | FS | STU | 278 |
| Star Air | S6 | SRR | |
| Star Air Aviation | 6S | URJ | |
| Star Airlines | SE | SEU | |
| Star Airways | Z3 | STW | 913 |
| StarFlyer | 7G | SFJ | |
| State Air Company Odessa Airlines | 5K | ODS | 654 |
| Stela Aviation Commercial Enterprise | |||
| Sterkh Air Company | STH | ||
| Sterling | NB | SNB | 194 |
| Strong Arm Air Cargo | |||
| Styrian Airlines | Z2 | STY | 536 |
| Suckling Airways | CB | SAY | |
| Sudan Airways | SD | SUD | 200 |
| Sun Air | BV | SSN | 928 |
| Sun Country Airlines | SY | SCX | 337 |
| Sun-Air of Scandinavia | EZ | SUS | |
| Sunexpress Air | XQ | SXS | 564 |
| Sunflower Airlines | PI | SUF | 252 |
| Sunjet International Airlines | JX | SJI | |
| Sunlight Airlines | 6L | SUH | |
| Sunrise Airlines | |||
| Sunstate | SSQ | ||
| Sunworld International Airlines | SM | SWI | 375 |
| Superior Aviation | HKA | ||
| Surinam Airways | PY | SLM | 192 |
| SVG St Vincent & Grenadines Air | SVD | ||
| Swedline Express | SM | SRL | |
| Swiftair | SWT | ||
| Swiss World Airways | SO | SWO | |
| Swiss WorldCargo | LX | SWR | 724 |
| Swisswings Airlines | RQ | RQX | 834 |
| Syrian Arab Airlines | RB | SYR | 070 |