| 1 | GRL | Greenlandair | IATA: GL, Callsign: Greenlandair, IATA Prefix: 631, Name changed to Air Greenland A/S / ICAO callsign changed to Greenland | GRO | AVCODES |
| 2 | GRL | Air Greenland A/S | IATA: GL, Callsign: Greenland, IATA Prefix: 631, Name changed from Greenlandair / ICAO callsign changed from Greenlandair | GRO | AVCODES |
| 3 | GRL | Gronlandsfly Ltd. | IATA: GL, Callsign: Greenlandair, IATA Prefix: 631, Name changed to Greenlandair | GRO | AVCODES |
| 4 | GRL | Air Greenland | IATA: GL | | ICAO1 |
| 5 | GRLA | GROUPE LAFRANCE | | | SCAC4 |
| 6 | GRLA | Greenville & Lafayette IBOA | | USA | TRAFFIC |
| 7 | GRLE | GREAT LAKE EXPRESS CO | | | PWRC |
| 8 | GRLE | GREENLAND EQUIPMENT LTD | | | SCAC4 |
| 9 | GRLL | GREELEYS OIL CO INC | | | SCAC4 |
| 10 | GRLQ | GREENLINE TRANSPORTATION LLC | | | SCAC4 |
| 11 | GRLR | GUTIERREZ LOREDO, TOMAS | | | SCAC4 |
| 12 | GRLS | GREAT LAND | | | SCAC4 |
| 13 | GRLT | GREAT LAKES TRANSPORTATION INC | | | SCAC4 |
| 14 | GRLU | GRUBER GMBH & CO.KG | | D | BIC |
| 15 | GRLU | GRUBER GMBH & CO KG | | | SCAC4 |
| 16 | GRLV | GRS LOGISTICS INC | | | SCAC4 |
| 17 | GRLW | GREENVILLE & WESTERN RAILWAY CO., LLC | | | PWRC |
| 18 | GRLW | Greenville & Western Railway (Western Carolina Railway Service Corporation) | | | RSRV |
| 19 | GRLW | GREENVILLE & WESTERN RAILWAY COMPAN | | | SCAC4 |
| 20 | GRLZ | GRAIN LAND COOP | | | PWRC |
