| 1 | SLL | Slovak Airlines, Inc. | IATA: 6Q, Callsign: Slov Line, IATA Prefix: 921, IATA designator changed from 9S | SK | AVCODES |
| 2 | SLL | Saarland Airlines | IATA: QW, Callsign: Saarland, Designator SX recalled by IATA. Declared bankrupt 28 July 1993. | D | AVCODES |
| 3 | SLL | Slovak Airlines | IATA: 9S, IATA designator changed to 6Q | SK | AVCODES |
| 4 | SLL | Skylink Aviation Limited | | EAK | AVCODES |
| 5 | SLL | Slovak Airlines | IATA: 6Q | | ICAO1 |
| 6 | SLLD | S T L TRANSPORTATION & LOGISTICS IN | | | SCAC4 |
| 7 | SLLE | STELLER & SONS LLC | | | SCAC4 |
| 8 | SLLL | SOUTHLAKE LOGISTICS LLC | | | SCAC4 |
| 9 | SLLM | ST LOGISTICS LLC | | | SCAC4 |
| 10 | SLLO | S & L LOGISTICS INC | | | SCAC4 |
| 11 | SLLS | SEAL LEASING LLC | | | SCAC4 |
| 12 | SLLU | SEA-LAND LOGISTICS ENTERPRISES PTE LTD | | SGP | BIC |
| 13 | SLLU | SEAWAY LINES, INC. | | | SCAC4 |
| 14 | SLLV | SULLIVANS TRUCKING LTD | | | SCAC4 |
| 15 | SLLX | ST. LOUIS & LAKE COUNTIES REGIONAL RAILROAD | | | PWRC |
