| 1 | XL | Country Connection Airlines Pty Ltd. | ICAO: NSW, Designator XL recalled by IATA | AUS | AVCODES |
| 2 | XL | Pro Air, Inc. | ICAO: PRH, Callsign: Prohawk, IATA desigantor changes to P9 | USA | AVCODES |
| 3 | XLA | Excel Airways | IATA: JN, Callsign: Expo, IATA Prefix: 812, Name changed to XL Airways UK Limited w.e.f. 23 November 2006. Name changed from Sabre Airways Ltd w.e.f. 01 November 2000. ICAO designator changed from SBE. ICAO callsign changed from Sabre | GB | AVCODES |
| 4 | XLA | XL Airways UK Limited | IATA: JN, Callsign: Expo, IATA Prefix: 812, Ceased operations on 12 September 2008. Name changed from Excel Airways w.e.f. 30 November 2006. Name changed from Sabre Airways Ltd w.e.f. 01 November 2000. ICAO designator changed from SBE. ICAO callsign changed from Sabre | GB | AVCODES |
| 5 | XLA | Excel Airways | IATA: JN | | ICAO1 |
| 6 | XLB | Aircraft Performance Group, Inc. | | USA | AVCODES |
| 7 | XLB | Aircraft Performance Group | | | ICAO1 |
| 8 | XLD | Jepenssen Data Plan, Inc. | Non-airline Org. in airline industry | USA | AVCODES |
| 9 | XLD | Jeppesen Data Plan | | | ICAO1 |
| 10 | XLE | NG Eagle Limited | Callsign: Aquila, ICAO designator changed from XGE. ICAO Callsign changed from Soaring Eagle. | WAN | AVCODES |
| 11 | XLEP | X L EXPRESS | | | SCAC4 |
| 12 | XLF | XL Airways France | IATA: SE, Callsign: Starway, IATA Prefix: 473, Name changed from STAR Airlines. ICAO designator changed from SEU. Name changed from STAR Europe (Societe de Transport Aerien Regional) IATA Designator changed from 2R | F | AVCODES |
| 13 | XLF | XL Airways France | IATA: SE, Callsign: Starway, IATA Prefix: 473, Ceased operations on 30 September 2019. Name changed from STAR Airlines. ICAO designator changed from SEU. Name changed from STAR Europe (Societe de Transport Aerien Regional) IATA Designator changed from 2R | F | AVCODES |
| 14 | XLG | Lockheed Air Terminal, Inc. | | GUM | AVCODES |
| 15 | XLG | Lockheed Air Terminal | | | ICAO1 |
| 16 | XLIC | XTC LOGISTICS INC | | | SCAC4 |
| 17 | XLII | XL INDUSTRIES INC | | | SCAC4 |
| 18 | XLIN | X-LINX INC | | | SCAC4 |
| 19 | XLIQ | XLI INC | | | SCAC4 |
| 20 | XLJ | Xcel Jet Management, Inc. | Callsign: Xcel Jet, | USA | AVCODES |
| 21 | XLK | Safarilink Aviation Limited | IATA: F2, Callsign: Safarilink, | EAK | AVCODES |
| 22 | XLK | Safarilink Aviation | | | ICAO1 |
| 23 | XLL | Air Excel | Callsign: Tinga-Tinga, | EAT | AVCODES |
| 24 | XLL | Air Excel | | | ICAO1 |
| 25 | XLMO | XCEL TRANSPORTATION LLC | | | SCAC4 |
| 26 | XLOG | XL LOGISTICS AND TRANSPORTATION COR | | | SCAC4 |
| 27 | XLR | Texel Air W.L.L. | Callsign: Texel, IATA Prefix: 565, Founded in 2013. | BRN | AVCODES |
| 28 | XLRT | XLR8 TRUCK LINES | | | SCAC4 |
| 29 | XLS | Excel Aire Service, Inc. | Callsign: Excel Aire, ICAO callsign changed to Excelaire | USA | AVCODES |
| 30 | XLS | ExcelAire, LLC | Callsign: Excelaire, ICAO callsign changed to Excel Aire. Owned by Hawthorne Global Aviation Services, LLC. | USA | AVCODES |
| 31 | XLT | Empresa Brasileira de Infraestrutura | Callsign: Infraero, | BR | AVCODES |
| 32 | XLT | Empressa Brasileira de Infra-Estrutura Aeroportuar | | | ICAO1 |
| 33 | XLTP | XTL LOGISTICS SERVICES INC | | | SCAC4 |
