| L´Aeropostale | ARP | ||
| Lab Flying Service | JF | LAB | 510 |
| LAC Colombia - Lineas Aereas del Caribe | LC | LIC | |
| LACSA-Lineas Aéreas Costarricenses | LR | LRC | 133 |
| Lagun Air | N7 | JEV | 504 |
| Laker Airways | 6F | LKR | 385 |
| Laker Bahamas | 7Z | LBH | 569 |
| LAM-Linhas Aereas de Mozambique | TM | LAM | 068 |
| LAN Airlines | LA | LAN | 045 |
| LAN Cargo | UC | LCO | 145 |
| Lan Peru | LP | LPE | 544 |
| Lao Airways | QV | LAO | 627 |
| LAP Colombia | APT | ||
| LAPA Lineas Aereas Privadas Argentinas | MJ | LPR | 069 |
| Laparkan Airways | LE | 969 | |
| LAR Transregional | TH | 259 | |
| LAS-Lineas Aereas Suramericanas | LAU | ||
| Lasare Air | LRE | ||
| Latavio - Latvian Airlines | PV | LTL | 559 |
| Latcharter | 6Y | LTC | |
| Latin Air | SJ | ||
| Latpass | LTP | ||
| Lauda Air | NG | LDA | 231 |
| Lauda Air Italy | L4 | LDI | 372 |
| Laus Air | LSU | ||
| Leisure Cargo Group | |||
| Leisure International Airways | LEI | 543 | |
| Lemanair | LMR | ||
| Lensibavia | LSB | ||
| Lesotho Airways | QL | LAI | 721 |
| LIAT (1974) | LI | LIA | 140 |
| Liberia World Airlines | LE | LWA | |
| Libyan Arab Airlines | LN | LAA | 148 |
| Lina Congo | GCB | ||
| LinAir Hungarian Regional Airline | LIN | ||
| Linea Aerea | KZ | LER | 722 |
| Lineas Aereas Allegro | LL | GRO | 902 |
| Lineas Aereas Azteca | ZE | LCD | 994 |
| Lineas Aereas Del Estado | 5U | LDE | 022 |
| Linjeflyg | LF | 247 | |
| Lion Airlines | JT | LNI | |
| Lloyd Aereo Boliviano (LAB) | LB | LLB | 051 |
| Loganair | LC | LOG | 122 |
| LOT Polish Airlines | LO | LOT | 080 |
| Lotus Air | TAS | ||
| LTE International Airways | XO | LTE | |
| LTU International Airways | LT | LTU | 266 |
| Lufthansa | LH | DLH | 220 |
| Lufthansa Cargo | LH | GEC | 020 |
| Lufthansa Cargo India | LF | LCI | 212 |
| Lufthansa CityLine | CL | CLH | 683 |
| Lupenga Aircharter | LUP | ||
| Luxair | LG | LGL | 149 |
| Luxavia/Flitestar/Trek Airways | GM | TKE | 805 |
| Lviv Airlines | 5V | UKW | |
| Lynden Air Cargo | L2 | LYC | 344 |