| 1 | GMR | Gold Coast Air, Inc. | Callsign: Expeditor, | USA | AVCODES |
| 2 | GMR | Golden Myanmar Airlines Public Co., Ltd | IATA: Y5, Callsign: Golden Myanmar, IATA Prefix: 509, Established in August 2012. Commenced operations on 11 January 2013. Ceased operations. | MYA | AVCODES |
| 3 | GMR | Georgia Midland R.R. Inc. | 1/2005 | | NAKINA |
| 4 | GMR | *GAINESVILLE MIDLAND RAILROAD CO. | | | PWRC |
| 5 | GMR | +GEORGIA MIDLAND RAILROAD, INC. | | | PWRC |
| 6 | GMR | GEORGIA MIDLAND RAILROAD INC | | | SCAC4 |
| 7 | GMRC | Green Mountain R.R. Corp. | 1/1975-7/2005 | | NAKINA |
| 8 | GMRC | Green Mountain R.R. Corp. | 1/75-7/2000 | | NRHS |
| 9 | GMRC | GREEN MOUNTAIN RAILROAD CORP. | | | PWRC |
| 10 | GMRC | Green Mountain Railroad | | | RSRV |
| 11 | GMRC | GREEN MOUNTAIN RAILROAD CORPORATION | | | SCAC4 |
| 12 | GMRC | Green Mountain R.R. Corp. | | USA | TRAFFIC |
| 13 | GMRE | GMR | | | SCAC4 |
| 14 | GMRF | GMR PHOENIX LLC | | | SCAC4 |
| 15 | GMRG | GMR LOGISTICS | | | SCAC4 |
| 16 | GMRJ | GUZMAN, ROY TRUCKING | | | SCAC4 |
| 17 | GMRK | G & M TRUCKING | | | SCAC4 |
| 18 | GMRL | GAMER LOGISTICS | | | SCAC4 |
| 19 | GMRM | GMR MARKETING LLC | | | SCAC4 |
| 20 | GMRN | GM TRANSPORT INC | | | SCAC4 |
| 21 | GMRO | GERMAINE RESTAURANT SUPPLY | | | SCAC4 |
| 22 | GMRR | GMR TRANSPORTATION | | | SCAC4 |
| 23 | GMRS | GENERAL MARINE SERVICE OF CHENIER I | | | SCAC4 |
| 24 | GMRU | MONROKO LIMITED | | | SCAC4 |
| 25 | GMRV | GLOBE METAL RECYCLING SERVICES | | | SCAC4 |
| 26 | GMRW | GILA MONSTER RACING INC | | | SCAC4 |
| 27 | GMRX | GREAT MIAMI RAILROAD | | | PWRC |
| 28 | GMRY | Great Miami & Scioto Ry. Co. | added 10/1998; 7/2000; eliminated 1/2001; 7/2005 | | NAKINA |
| 29 | GMRY | Great Miami & Scioto Ry. Co. | added 10/98; 7/2000; eliminated 1/2001 | | NRHS |
| 30 | GMRY | GREAT MIAMI & SCIOTO RAILWAY COMPANY | | | PWRC |
| 31 | GMRY | Great Miami and Scioto Railway | | | RSRV |
| 32 | GMRY | GREAT MIAMI & SCIOTO RAILWAY COMPAN | | | SCAC4 |
| 33 | GMRY | Great Miami & Scioto Railway | | USA | TRAFFIC |
