| 1 | GRA | Great American Airways | Callsign: Great American, AOC revoked on 13 April 1997. | USA | AVCODES |
| 2 | GRA | Guardian Air Asset Management (Pty) Ltd. | Callsign: Flex, | ZA | AVCODES |
| 3 | GRA | Great American Airways | | | ICAO1 |
| 4 | GRA | GRAY LINE COMPANY, THE | | | SCAC4 |
| 5 | GRAA | GRASS, M E & SONS INC | | | SCAC4 |
| 6 | GRAF | Gräf & Stift | since 2002 subsidiary of MAN | A | TRAFFIC |
| 7 | Graf MEC | Grafschafter Modell-Eisenbahnclub e.V. | Nordhorn | D | privat-bahn.de |
| 8 | GRAG | Ing. Greuter AG | | CH | VKM |
| 9 | GRAH | GREAT AMERICAN MOVERS (A CORPORATIO | | | SCAC4 |
| 10 | GRAJ | GARCIA ALEGRIA, ROBERTO | | | SCAC4 |
| 11 | GRAK | GARCHA, D TRUCKING LTD | | | SCAC4 |
| 12 | GRAM | GRAHAM SHIP BY TRUCK COMPANY | | | SCAC1 |
| 13 | GRAN | Greater Anglia | | GB | TRAFFIC |
| 14 | GRAN | Bauunternehmung Granit GmbH | | AT | VKM |
| 15 | GRAQ | GRANITE CREATIONS INC | | | SCAC4 |
| 16 | GRAS | GROSHELL TRANSPORTATION SERVICES IN | | | SCAC4 |
| 17 | GRAS | JKP GRAS Sarajevo (Javno Komunalno Preduzeće – Gradski Saobraćaj Sarajevo) | | BIH | TRAFFIC |
| 18 | GRAS | Grenland rail AS | | NO | VKM |
| 19 | GRAV | GUTIERREZ AVALOS, ALFONSO | | | SCAC4 |
| 20 | GRAW | GRAY, GARY W | | | SCAC1 |
| 21 | GRAX | Grax Corp. | added 7/1965; 7/1965-10/1966; eliminated 7/1968 | | NAKINA |
| 22 | GRAX | Grax Corp. | added 7/65; 7/65-10/66; eliminated 7/68 | | NRHS |
| 23 | GRAX | GRAX CORP. | | | PWRC |
| 24 | GRAX | GRAYMONT (PA) INC | | | SCAC4 |
| 25 | GRAY | Gray Coach Lines | | CDN | TRAFFIC |