| 501 | GAVX | GAVILON LLC | | | SCAC4 |
| 502 | GAW | Global Airlift Limited | Callsign: Skycrawler, | EAK | AVCODES |
| 503 | GAW | Gambia Airways | IATA: GW, Callsign: The Gambia, Designator GW recalled by IATA | WAG | AVCODES |
| 504 | GAW | GREEN ACRES WOODLAND, INC. | | | PWRC |
| 505 | GAWC | G& W CARTAGE | | | SCAC1 |
| 506 | GAWC | G & W CARTAGE INC | | | SCAC4 |
| 507 | GAWR | GEORGES AUTO WRECKERS AND RECYCLING | | | SCAC4 |
| 508 | GAWU | GATEWAY CONTAINER INTERNATIONAL LIMITED | | BVI | BIC |
| 509 | GAWX | Union Tank Car Co. | added 4/1956; 10/1957; eliminated 1/1958 | | NAKINA |
| 510 | GAWX | General Analine & Film Corp., Dyestuff and Chemical Division | added 1/1955; eliminated 4/1956 | | NAKINA |
| 511 | GAWX | General Analine & Film Corp., General Aniline Works Division | 1/1941-7/1954; eliminated 1/1955 | | NAKINA |
| 512 | GAWX | General Analine Works, Inc. | 7/1937-4/1938 (not listed) | | NAKINA |
| 513 | GAWX | General Analine & Film Corp., General Aniline Works Division | Jan-52 | | NRHS |
| 514 | GAWX | Union Tank Car Co. | 10/57; eliminated 1/58 | | NRHS |
| 515 | GAWX | UNION TANK CAR CO. (GENERAL ANALINE & FILM CORP.) | | | PWRC |
| 516 | GAX | Full Express, Inc. | Callsign: Grand Aire, | USA | AVCODES |
| 517 | GAX | Global International Airways | IATA: GX, Callsign: Global, | USA | AVCODES |
| 518 | GAX | Full Express | | | ICAO1 |
| 519 | GAXL | GREAT AMERICAN LINES INC | | | SCAC4 |
| 520 | GAXN | G & A TRANSPORTATION | | | SCAC4 |
| 521 | GAXO | G & A TRANSPORTATION | | | SCAC4 |
| 522 | GAXP | G A XPRESS | | | SCAC4 |
| 523 | GAXS | GAXIOLA SANCHEZ, ARACELI | | | SCAC4 |
| 524 | GAXT | GAMTEX TRUCKING LLC | | | SCAC4 |
| 525 | GAXU | GAZECHIM S.A. | | | SCAC4 |
| 526 | GAXX | Gerdau Ameristeel US, Inc. | added 7/2006 | | NAKINA |
| 527 | GAXX | GERDAU AMERISTEEL US, INC. | | | PWRC |
| 528 | GAXX | GERDAU AMERISTEEL US INC | | | SCAC4 |
| 529 | GAYC | GAY OIL COMPANY INC | | | SCAC4 |
| 530 | GAYD | GAYS WREATHS | | | SCAC4 |
| 531 | GAYL | GAYLORD FEED AND GRAIN INC | | | SCAC4 |
| 532 | GAYT | GAY TRUCK LINE, INC | | | SCAC1 |
| 533 | GAYU | SA ELECTRICITY GAY | | F | BIC |
| 534 | GAYX | General American Transportation Corp. | added 7/1972; 1/1975-1/1980; eliminated 10/1992 | | NAKINA |
| 535 | GAYX | General American Transportation Corp. | 1/75-1/80; eliminated 10/92 | | NRHS |
| 536 | GAYX | RETIRED 08-19-92 ATP (1861) [GATX] | | | PWRC |
| 537 | GAYX | General American Transportation Corporation (GATX) | | | RSRV |
| 538 | GAYZ | GAYLORD MILL | | | PWRC |
| 539 | GAZ | Global Aviation Pte Ltd. | Ceased operations | SGP | AVCODES |
| 540 | GAZI | GAZPROM MARKETING & TRADING USA INC | | | SCAC4 |
| 541 | GAZU | TEXTAINER EQUIPMENT MANAGEMENT LTD | | BM | BIC |
| 542 | GAZU | GATEWAY MANAGEMENT SERVICES LIMITED | | | SCAC4 |
| 543 | GB | ABX Air, Inc. | ICAO: ABX, Callsign: Abex, IATA Prefix: 832, Name changed from Airborne Express, Inc. | USA | AVCODES |
| 544 | GB | Airborne Express, Inc. | ICAO: ABX, Callsign: Abex, IATA Prefix: 832, Name changed to ABX Air, Inc. Designator AE recalled by IATA | USA | AVCODES |
| 545 | GB | Air Glaciers | ICAO: AGV, Callsign: Alpha Golf Vict, IATA designator changed to 7T* | CH | AVCODES |
| 546 | GB | Great Barrier Airlines | ICAO: AFW, | NZ | AVCODES |
| 547 | GB | Société de Transports Aériens du Gabon | | G | AVCODES |
| 548 | GB | Globus LLC | IATA designator changed to GH | RUS | AVCODES |
| 549 | GB | Transportes Aereos da Guine-Bissau | Callsign: Transbissau, | GW | AVCODES |
| 550 | GB | unknown in Great Britain | | GB | TRAFFIC |
| 551 | GB&W | Green Bay & Western R.R. Co. | 8/1920-7/1930 & 7/1936 | | NAKINA |
| 552 | GB&W | GREEN BAY & WESTERN RAILROAD CO. | | | PWRC |
| 553 | GBA | Gulf Air Bahrain B.S.C. | Callsign: Gulf Bahrain, | BRN | AVCODES |
| 554 | GBA | Georgian Bay Airways | Callsign: Georgian Bay, | CDN | AVCODES |
| 555 | GBA | Gulf Air Bahrain | IATA: GF | | ICAO1 |
| 556 | GBAC | GURRISI BROTHERS AUTO & TRUCK SALES | | | SCAC4 |
| 557 | GBAD | GARCIA BLANCAS, AMADO | | | SCAC4 |
| 558 | GBAE | G & B FARMS LTD | | | SCAC4 |
| 559 | GBAG | Gelsenkirchener Bergwerks-AG | | D | TRAFFIC |
| 560 | GBAJ | GBA TRANSPORT LLC | | | SCAC4 |
| 561 | GBAK | G B TRANSPORT LLC | | | SCAC4 |
| 562 | GBAM | GLOBAL MESSENGER CORPORATION | | | SCAC4 |
| 563 | GBAN | GLOBAL TRANS AMERICA INC | | | SCAC4 |
| 564 | GBAP | GB AND SONS TRANSPORT INC | | | SCAC4 |
| 565 | GBAT | GLOBAL LOGISTICS SOLUTIONS | | | SCAC4 |
| 566 | GBAU | BAUTRU ET CIE | | | SCAC3 |
| 567 | GBB | Global Aviation Operations (PTY) Ltd | IATA: QG, Designator QG recalled by IATA | ZA | AVCODES |
| 568 | GBB | Global Aviation Operations (Pty) Ltd | IATA: GE, Callsign: Globe, Designator QG recalled by IATA | ZA | AVCODES |
| 569 | GBB | Global Aviation Operations | | | ICAO1 |
| 570 | GBBC | GOLDEN BRAND BOTTLING CO INC | | | SCAC4 |
| 571 | GBBD | GLOBAL BEST BEAUTY TRADING LTD | | | SCAC4 |
| 572 | GBBG | GLOBAL BRILLIANT LOGISTICS CORP | | | SCAC4 |
| 573 | GBBJ | Grängesbergsbanornas Järnvägsmuseum | | SE | VKM |
| 574 | GBBL | GRIBBLE TRANSPORT INC | | | SCAC4 |
| 575 | GBBM | GRAEBEL NEW ENGLAND MOVERS INC | | | SCAC4 |
| 576 | GBBO | GIBBONS, JOHN PONTIAC BUICK GMC LTD | | | SCAC4 |
| 577 | GBBQ | G B T | | | SCAC4 |
| 578 | GBBR | GRUBB TRUCKING | | | SCAC4 |
| 579 | GBBY | GALIB ENTERPRISES LTD | | | SCAC4 |
| 580 | GBC | Globe Air Cargo | Callsign: Globe Cargo, | AG | AVCODES |
| 581 | GBCA | GLOBAL CONSOLIDATION SERVICES | | | SCAC1 |
| 582 | GBCB | GIBBS BROTHERS CONSTRUCTION INC | | | SCAC4 |
| 583 | GBCC | GESTION SAGBY INC | | | SCAC4 |
| 584 | GBCD | GIESBRECHT, SEAN | | | SCAC4 |
| 585 | GBCE | GREEN BELT CARRIERS | | | SCAC4 |
| 586 | GBCF | GLOBAL CFS INC | | | SCAC4 |
| 587 | GBCI | GRANI-BOIS CONCEPT INC | | | SCAC4 |
| 588 | GBCJ | GRANNAS BROS CONTRACTING CO INC | | | SCAC4 |
| 589 | GBCM | GIBCO MOTOR EXPRESS LLC | | | SCAC4 |
| 590 | GBCN | GLOBE COM LINES INC. | | | SCAC4 |
| 591 | GBCP | GLOBAL COMPANIES LLC | | | SCAC4 |
| 592 | GBCQ | GENERAL BINDING CORPORATION | | | SCAC4 |
| 593 | GBCR | DSR SHIPPING CO. INC. | | | SCAC1 |
| 594 | GBCT | GRAEBEL CONNECTICUT MOVERS INC | | | SCAC4 |
| 595 | GBCU | GLOBAL CONTAINER CONCEPTS | | | SCAC4 |
| 596 | GBCV | GLOBAL COURIER SERVICE LTD | | | SCAC4 |
| 597 | GBCX | Genesee Brewing Co. (Merchants Despatch, Inc.) | 7/1935 | | NAKINA |
| 598 | GBCY | GLOBAL CCSF INC | | | SCAC4 |
| 599 | GBDB | GABER DISTRIBUTORS | | | SCAC4 |
| 600 | GBDK | GOBIND TRUCKING INC | | | SCAC4 |
