| 1 | SWL | Southwest Airlines | IATA: NU, Callsign: Nansei, | USA | AVCODES |
| 2 | SWL | Transjet Airways AB | IATA: S9, Callsign: Transjet, Operating Licence revoked on 09 July 2002. Name changed from SAE SWE Aviation Europe AB / Callsign changed. IATA changed from S6* | S | AVCODES |
| 3 | SWL | SAE SWE Aviation Europe AB | IATA: S9, Callsign: Swing, Name changed to Trans Jet Airways AB / Callsign changed. IATA changed from S6* | S | AVCODES |
| 4 | SWL | Southwest Air Lines Ltd. | IATA: NU, Callsign: Nansei, | USA | AVCODES |
| 5 | SWL | Southwings (Thailand) Co., Ltd. | Callsign: South Wings, | T | AVCODES |
| 6 | SWL | Trans Jet Airways | | | ICAO1 |
| 7 | SWL | Stadtwerke Lübeck | | D | TRAFFIC |
| 8 | SWLA | SMART WAY LOGISTICS LLC | | | SCAC4 |
| 9 | SWLB | SOUTHWEST LOBSTER | | | SCAC4 |
| 10 | SWLC | SEAWORLD EXPRESS LINE LIMITED | | | SCAC4 |
| 11 | SWLD | SEAWORLD MANAGEME | | | SCAC4 |
| 12 | SWLF | SWAIM LOGISTICS LLC | | | SCAC4 |
| 13 | SWLH | SW LOGISTICS INC | | | SCAC4 |
| 14 | SWLI | SOUTHWEST LIVESTOCK & TRUCKING CO I | | | SCAC4 |
| 15 | SWLIN | Stadtwerke Lindau | City: Lindau | D | TRAFFIC |
| 16 | SWLJ | STAR WAY LINES INC | | | SCAC4 |
| 17 | SWLK | SIMS, WALKER OIL CO INC | | | SCAC4 |
| 18 | SWLM | SOUTHWEST LOGISTICS MANAGEMENT INC | | | SCAC4 |
| 19 | SWLN | SEAWAY LINES | | | PWRC |
| 20 | SWLR | SHOWALTER INC | | | SCAC4 |
| 21 | SWLU | SAMSKIP MCL BV | | NL | BIC |
| 22 | SWLU | SEAWHEEL LIMITED | | | SCAC4 |
| 23 | SWLV | SAFEWATER LINES (INDIA) PRIVATE LIM | | | SCAC4 |
| 24 | SWLX | Southwestern Tank Line Co. | 7/1932 | | NAKINA |
| 25 | SWLX | Southwestern Tank Line (Bartex Pipe Line Co.) | 7/1935 | | NAKINA |
| 26 | SWLX | Phillips Petroleum Co. | 7/1937-1/1946 | | NAKINA |
| 27 | SWLX | Essel Corp. | 10/1957; eliminated 10/1959 | | NAKINA |
| 28 | SWLX | Essel Petroleum Corp. | added 10/1957; added 10/1959; 4/1961-4/1970; eliminated 1/1974 | | NAKINA |
| 29 | SWLX | Essel Corp. | added 1/1974, 1/1975-1/1980; eliminated 10/1984 | | NAKINA |
| 30 | SWLX | Southwestern Tank Line Co. (Phillips Petroleum Co.) | Apr-38 | | NRHS |
| 31 | SWLX | Essel Corp. | 10/57; eliminated 10/59 | | NRHS |
| 32 | SWLX | Essel Petroleum Corp. | added 10/57; added 10/59; 4/61-4/70 | | NRHS |
| 33 | SWLX | Essel Corp. | 1/75-1/80; eliminated 10/84 | | NRHS |
| 34 | SWLX | *PHILLIPS PETROLEUM CO. [SOUTHWESTERN TANK LINE CO.] | | | PWRC |
| 35 | SWLX | *ESSEL CORPORATION | | | PWRC |
| 36 | SWLX | Essel Corporation | | | RSRV |
| 37 | SWLX | ESSEL PETROLEUM CORP | | | SCAC3 |
| 38 | SWLY | SWIFT LOGISTICS INC | | | SCAC4 |
| 39 | SWLZ | UNION PACIFIC [(SSW) ST. LOUIS SOUTHWESTERN] | | | PWRC |
