| SAA | SA | 083 | South African Airways Cargo |
| SAH | W7 | 271 | Sayakhat Air Company |
| SAI | NL | 740 | Shaheen Air International |
| SAM | MM | 334 | Sociedad Aeronautica de Medellin (SAM) |
| SAN | WB | 739 | SAN Servicios Aereos Nacionales |
| SAS | SK | 117 | SAS-Scandinavian Airlines System |
| SAT | SP | 737 | SATA - Air Açores |
| SAY | CB | Suckling Airways | |
| SBE | TJ | Sabre Airways | |
| SBI | S7 | 421 | S7 Airlines |
| SBR | Saber Aviation | ||
| SBX | North Star Aircargo | ||
| SBY | FC | 859 | TAL Thuringia Airlines |
| SBZ | ZM | 939 | Scibe Airlift |
| SCA | XE | 301 | South Central Air |
| SCB | 2E | 602 | Sky Cabs |
| SCH | AW | 405 | Schreiner Airways |
| SCI | C7 | 424 | Special Cargo Airlines |
| SCO | YQ | Helikopterservice- Euro Air | |
| SCW | TF | 276 | Malmö Aviation |
| SCX | SY | 337 | Sun Country Airlines |
| SDK | SADELCA - Sociedad Aerea del Caqueta | ||
| SDL | Skydrift Ltd | ||
| SDM | FV | 195 | Rossiya Airlines |
| SEA | Southeast Airways | ||
| SEE | 587 | Shaheen Air Cargo | |
| SEH | G3 | Sky Express | |
| SEJ | SG | SpiceJet | |
| SER | JR | 078 | Aero California |
| SET | EH | 156 | SAETA-Soc.Ecuatoriana de Transp.Aereos |
| SEU | SE | Star Airlines | |
| SEY | HM | 061 | Air Seychelles |
| SFB | CT | 551 | Air Sofia |
| SFC | 3S | Shuswap Air | |
| SFJ | 7G | StarFlyer | |
| SFN | Safiran | ||
| SFR | FA | 640 | Safair |
| SFW | 4Q | Safi Airways | |
| SGK | K9 | 470 | Skyward Aviation |
| SHA | SH | 274 | SAHSA-Servicios Aereo de Honduras |
| SHB | SS | Shabair | |
| SHD | S2 | 705 | Sahara Airlines |
| SHK | 7Q | 273 | Shorouk Air |
| SHU | HZ | 598 | SAT Airlines |
| SHY | Sky Airlines | ||
| SIA | SQ | Singapore Airlines | |
| SIB | 5M | 842 | Sibavia |
| SIH | SI | 597 | Skynet Airlines |
| SIR | 8S | 477 | Air Alaska Cargo |
| SJI | JX | Sunjet International Airlines | |
| SJM | SJ | 351 | Southern Air |
| SJM | SJ | 351 | Southern Air |
| SJY | Sriwijaya Air | ||
| SKA | 062 | Skyjet Brasil | |
| SKB | SX | Skybus | |
| SKI | RU | 025 | Skyking Airlines |
| SKK | SkyLink Aviation | ||
| SKW | OO | 302 | Sky West Airlines |
| SKX | JZ | 752 | Skyways AB |
| SKY | BC | Skymark Airlines | |
| SKZ | Sky Way Enterprises | ||
| SLA | LJ | 690 | Sierra National Airlines |
| SLI | 5D | 642 | Aerolitoral |
| SLK | MI | 629 | SilkAir |
| SLL | 6Q | 921 | Slovak Airlines |
| SLM | PY | 192 | Surinam Airways |
| SLP | Salpa Sudan | ||
| SLR | 644 | Sobelair | |
| SMB | Simba Air Cargo | ||
| SMJ | Z3 | 757 | Avient Aviation |
| SMM | VIP Xpress Co | ||
| SMX | XM | Alitalia Express | |
| SMZ | Sonmez Airlines | ||
| SNB | NB | 194 | Sterling |
| SNC | 2Q | Air Cargo Carriers | |
| SND | S3 | San Cargo Kazakhstan | |
| SNG | V7 | 407 | Air Senegal International |
| SNJ | 6J | Skynet Asia Airways | |
| SOA | Skoda Engineering Air Transport | ||
| SOL | IE | 193 | Solomon Airlines |
| SOM | Somali Airlines | ||
| SOO | 9S | Southern Air | |
| SOV | 6W | 026 | Saratov Aviation Division |
| SPA | SI | Sierra Pacific Airlines | |
| SPB | ASA - St Petersburg American Airlines | ||
| SPI | South Pacific Island Airways | ||
| SPN | Scorpion Air | ||
| SPP | Sapphire Aviation | ||
| SPR | PB | 967 | Provincial Airlines |
| SQC | SQ | 618 | Singapore Airlines Cargo |
| SRH | FT | Siem Reap Airways International | |
| SRL | SM | Swedline Express | |
| SRO | UF | Saro Airlines | |
| SRR | S6 | Star Air | |
| SSN | BV | 928 | Sun Air |
| SSQ | Sunstate | ||
| SSR | SG | 821 | Sempati Air |
| SSV | 884 | Skyservice | |
| STA | T8 | STA Trans African Airlines | |
| STH | Sterkh Air Company | ||
| STT | ZP | 315 | Air St Thomas |
| STU | FS | 278 | STAF Airlines |
| STV | Southern Aviation | ||
| STW | Z3 | 913 | Star Airways |
| STY | Z2 | 536 | Styrian Airlines |
| SUD | SD | 200 | Sudan Airways |
| SUF | PI | 252 | Sunflower Airlines |
| SUH | 6L | Sunlight Airlines | |
| SUL | PE | 153 | Helisul Linhas Aereas |
| SUS | EZ | Sun-Air of Scandinavia | |
| SVA | SV | 065 | Saudi Arabian Airlines |
| SVD | SVG St Vincent & Grenadines Air | ||
| SVI | SETRA - Servicio de Transporte Aereo | ||
| SVK | GM | Air Slovakia | |
| SVL | Saak-Gem Air Company | ||
| SVR | U6 | 262 | Ural Airlines |
| SVT | Sakhavia Trans | ||
| SVV | VC | 985 | Servivensa-Empresa Servicios Avensa |
| SWA | WN | 526 | Southwest Airlines |
| SWD | A4 | 242 | Southern Winds |
| SWG | NK | 487 | Spirit Airlines |
| SWI | SM | 375 | Sunworld International Airlines |
| SWN | PT | 869 | West Air Sweden |
| SWO | SO | Swiss World Airways | |
| SWR | LX | 724 | Swiss WorldCargo |
| SWT | Swiftair | ||
| SWW | IS | Intersun Havacilik | |
| SXS | XQ | 564 | Sunexpress Air |
| SYL | R3 | Yakutia Airlines | |
| SYR | RB | 070 | Syrian Arab Airlines |
| SYX | AL | Midwest Connect | |
| SYZ | 751 | Southend Cargo Airlines | |
| SZA | VG | AESA-Aerolineas de El Salvador |