| 1 | GL | Greenlandair | ICAO: GRL, Callsign: Greenlandair, IATA Prefix: 631, Name changed to Air Greenland A/S / ICAO callsign changed to Greenland | GRO | AVCODES |
| 2 | GL | Miami Air International, Inc. | ICAO: BSK, Callsign: Biscayne, IATA designator changed to LL* | USA | AVCODES |
| 3 | GL | Air Greenland A/S | ICAO: GRL, Callsign: Greenland, IATA Prefix: 631, Name changed from Greenlandair / ICAO callsign changed from Greenlandair | GRO | AVCODES |
| 4 | GL | Gronlandsfly Ltd. | ICAO: GRL, Callsign: Greenlandair, IATA Prefix: 631, Name changed to Greenlandair | GRO | AVCODES |
| 5 | GL | Eagles S.p.A. | ICAO: EGS, IATA desinator changed to E3 | I | AVCODES |
| 6 | GL | AirGlow Aviation Services FZC | IATA Prefix: 914, | UAE | AVCODES |
| 7 | GL | GREYHOUND LINES INC | | | SCAC4 |
| 8 | GL | Green Line coaches | | GB | TRAFFIC |
| 9 | GL&N | Groveton, Lufkin & Northern Ry. Co. | 8/1920-7/1930 | | NAKINA |
| 10 | GL&N | GROVETON, LUFKIN & NORTHERN RWY. CO. | | | PWRC |
| 11 | GLA | Great Lakes Aviation Ltd. | IATA: ZK, Callsign: Lakes Air, IATA Prefix: 846, Ceased operations on 26 March 2018. | USA | AVCODES |
| 12 | GLA | Great Lakes Airlines | IATA: ZK | | ICAO1 |
| 13 | GLA | Great Lakse Airlines | | USA | TRAFFIC |
| 14 | GLAB | GLABS TRUCKING | | | SCAC4 |
| 15 | GLAD | GLAD LOGISTICS INC | | | SCAC4 |
| 16 | GLAF | G L J FISHING CO LTD | | | SCAC4 |
| 17 | GLAH | GLADWIN FARMS LTD | | | SCAC4 |
| 18 | GLAI | GREAT LAKES AND INTERNATIONAL TOWIN | | | SCAC4 |
| 19 | GLAL | GLOBAL ALLIANCE LOGISTICS INC | | | SCAC4 |
| 20 | GLAO | GRAEBEL/LOS ANGELES MOVERS INC | | | SCAC4 |
| 21 | GLAS | | City: Glasgow | GB | TRAFFIC |
| 22 | GLASC | Glasgow Corporation | | GB | TRAFFIC |
| 23 | GLAU | GASPRO LATINOAMERICA S.A | | PA | BIC |
| 24 | GLAU | AVV. DOTT. SERGIO GUGLIELMETTI | | | SCAC3 |
| 25 | GLAZ | GREAT LAKES INDUSTRIES | | | PWRC |
| 26 | GLB | Air Castle Corp. d/b/a Global Airways, California Airways, Global Aviation | Callsign: Glo-Air, | USA | AVCODES |
| 27 | GLB | Global Air Company LLP | Callsign: Global, | UA | AVCODES |
| 28 | GLB | Global Airways (GLB) | | | ICAO1 |
| 29 | GLBB | GLOBALGLAS SA | | | SCAC4 |
| 30 | GLBC | GORDON LUMBER COMPANY, THE | | | SCAC4 |
| 31 | GLBD | GREAT LITTLE BOX COMPANY LTD | | | SCAC4 |
| 32 | GLBE | GLOBO EXPRESS | | | SCAC4 |
| 33 | GLBF | GLOBAL LOGISTICS INC | | | SCAC4 |
| 34 | GLBF | Globalfer S.p.A. | | I | TRAFFIC |
| 35 | GLBF | GLOBALFER S.P.A. | | IT | VKM |
| 36 | GLBH | GLEBA INCORPORATED | | | SCAC4 |
| 37 | GLBK | GILL, B TRUCKING LTD | | | SCAC4 |
| 38 | GLBN | GLOBAL INTERNATIONAL | | | SCAC4 |
| 39 | GLBO | GLOBAL CARRIER INC. | | | SCAC4 |
| 40 | GLBP | GILBERTSON TRUCKING LTD | | | SCAC4 |
| 41 | GLBS | GILBERT & SONS TRUCKING, INC. | | | SCAC1 |
| 42 | GLBS | GILBERT & SONS TRUCKING INC | | | SCAC4 |
| 43 | GLBU | LANXESS CORPORATION | | USA | BIC |
| 44 | GLBU | Chemtura Corporation | | | RSRV |
| 45 | GLBV | GLOBAL EXPRESS SERVICES CORP | | | SCAC4 |
| 46 | GLBZ | TRAC LEASE INC. | | | PWRC |
| 47 | GLBZ | Trac Lease | | | RSRV |
| 48 | GLC | Global Aircargo Co. | | BRN | AVCODES |
| 49 | GLC | Galecor, Inc. | | USA | AVCODES |
| 50 | GLC | Global Aircargo | | | ICAO1 |
| 51 | GLC | GREAT LAKES CENTRAL RAILROAD | | | PWRC |
| 52 | GLC | Great Lakes Central Railroad | | | RSRV |
| 53 | GLC | GREAT LAKES CENTRAL RAILROAD | | | SCAC4 |
| 54 | GLC | Great Lakes Central Railroad | | USA | TRAFFIC |
| 55 | GLCA | GLC OCEAN LINES LIMITED | | | SCAC4 |
| 56 | GLCG | GILCO TRUCKING | | | SCAC4 |
| 57 | GLCJ | GLC TRANSPORTATION INC | | | SCAC4 |
| 58 | GLCK | GALLATIN TRANSPORTATION INC | | | SCAC4 |
| 59 | GLCM | GENESIS ATTACHMENTS LLC | | | SCAC4 |
| 60 | GLCO | GUILLORY OIL CO INC | | | SCAC4 |
| 61 | GLCQ | GULFSTREAM FUELING INC | | | SCAC4 |
| 62 | GLCS | GIL CASTRO, LAURA LUZ ELENA | | | SCAC4 |
| 63 | GLCU | FLEXI-VAN LEASING, INC. | | | PWRC |
| 64 | GLCU | Flex-Van Leasing (Goldline Container) | | | RSRV |
| 65 | GLCX | Great Lakes Carbon LLC | added 1/2004; 7/2005 | | NAKINA |
| 66 | GLCX | Great Lakes Carbon Corp. | added 4/1973; 1/1975-7/2000; eliminated 1/2004 | | NAKINA |
| 67 | GLCX | Great Lakes Chemical Corp. | added 1/1961; 4/1961-7/1965; eliminated 1/1966 | | NAKINA |
| 68 | GLCX | Great Lakes Chemical Corp., Division of Great Lakes Oil and Chemical Co. | elimiminated 1/1961 | | NAKINA |
| 69 | GLCX | Great Lakes Chemical Corp. | added 10/1958 | | NAKINA |
| 70 | GLCX | Great Lakes Car Line Corp. | 1/1943 (not listed) | | NAKINA |
| 71 | GLCX | Great Lakes Chemical Corp. | added 10/58; 4/61-7/65; eliminated 1/66 | | NRHS |
| 72 | GLCX | Great Lakes Carbon Corp. | added 4/73; 1/75-7/2000 | | NRHS |
| 73 | GLCX | *GREAT LAKES CAR LINE CORP. | | | PWRC |
| 74 | GLCX | *GREAT LAKES CHEMICAL CORP. | | | PWRC |
| 75 | GLCX | +GREAT LAKES CARBON LLC | | | PWRC |
| 76 | GLCX | Great Lakes Carbon | | | RSRV |
| 77 | GLCX | GREAT LAKES CARBON LLC | | | SCAC4 |
| 78 | GLCY | GLANCY TRUCKING | | | SCAC4 |
| 79 | GLCZ | GREAT LAKES COTTON CORPORATION | | | PWRC |
| 80 | GLD | Golden Star Air Cargo Co. Ltd. | Callsign: Golden Star, | SUD | AVCODES |
| 81 | GLD | Golden Star Air Cargo | | | ICAO1 |
| 82 | GLD | GRAY LINE OF DENVER | | | SCAC4 |
| 83 | GLDF | GOLD COAST FREIGHTWAYS, INC | | | SCAC1 |
| 84 | GLDF | GOLD COAST FREIGHTWAYS INC | | | SCAC4 |
| 85 | GLDG | GOLDEN GATE PETROLEUM | | | SCAC4 |
| 86 | GLDI | GLOVA-LINK DISTRIBUTION INC | | | SCAC4 |
| 87 | GLDL | GOLD LINE TRANSPORT INC | | | SCAC4 |
| 88 | GLDM | GOLDSTAR LOGISTICS LLC | | | SCAC4 |
| 89 | GLDN | GOLDEN STRIP TRANSFER, INC | | | SCAC1 |
| 90 | GLDN | GOLDEN STRIP TRANSFER INC | | | SCAC4 |
| 91 | GLDQ | G & L DISTRIBUTION | | | SCAC4 |
| 92 | GLDT | GOLDEN CHARIOT TRUCK LINE, INC | | | SCAC1 |
| 93 | GLDU | TOUAX GROUP | | F | BIC |
| 94 | GLDU | GOLD CONTAINER CORP | | | SCAC4 |
| 95 | GLDV | GOLD TRANSPORTATION SERVICES | | | SCAC4 |
| 96 | GLDW | GOLDEN WEST TRANSPORTATION | | | SCAC4 |
| 97 | GLDX | Glades Gas Co. | added 7/1961; 7/1965; eliminated 4/1966 | | NAKINA |
| 98 | GLDX | Glades Gas Co. | 7/65; eliminated 4/66 | | NRHS |
| 99 | GLDX | GLADES GAS CO. | | | PWRC |
| 100 | GLDY | GOLD COUNTRY TRUCKING | | | SCAC4 |
