| 1 | GSM | Globespan Airways Limited t/a Flyglobespan | IATA: B4, Callsign: Globespan, IATA Prefix: 060, IATA designator change to Y2 | GB | AVCODES |
| 2 | GSM | Globespan Airways Limited t/a Flyglobespan | IATA: Y2, Callsign: Globespan, IATA Prefix: 060, Ceased operations on 16 December 2009. Designator Y2 reinsated by IATA. IATA designator change from B4 | GB | AVCODES |
| 3 | GSM | Gestair Aviation Malta Limited | Callsign: Gestair Malta, | M | AVCODES |
| 4 | GSM | Flyglobespan | IATA: B4 | | ICAO1 |
| 5 | GSM | Great Smokey Mountains Ry. | 1/1994-7/2005 | | NAKINA |
| 6 | GSM | Great Smokey Mountains Ry. | 1/94-7/2000 | | NRHS |
| 7 | GSM | GREAT SMOKEY MOUNTAINS RAILWAY, INC. | | | PWRC |
| 8 | GSM | Great Smoky Mountains Railroad | | | RSRV |
| 9 | GSM | GSM | | NL | TRAFFIC |
| 10 | GSMB | GIALIS MACHINERY INC | | | SCAC4 |
| 11 | GSMG | GO SYSTEMS MRO LOGISTICS | | | SCAC4 |
| 12 | GSMI | GSM TRANSPORTATION LLC | | | SCAC4 |
| 13 | GSMK | GROSSMAN TRUCKING | | | SCAC4 |
| 14 | GSML | GERON ASSOCIATES LIMITED | | | SCAC4 |
| 15 | GSMM | GOLD STAR MARITIME COMPANY | | | SCAC4 |
| 16 | GSMN | GROSSMAN, RIK | | | SCAC4 |
| 17 | GSMO | GASMART TRANSPORT LLC | | | SCAC4 |
| 18 | GSMP | GLORIOUS STEAMSHIP INC | | | SCAC4 |
| 19 | GSMQ | GS | | | SCAC4 |
| 20 | GSMR | GULF & MISSISSIPPI RAILROAD CORP. | | | PWRC |
| 21 | GSMS | GRAND STRAND MOVING & STORAGE LLC | | | SCAC4 |
| 22 | GSMT | GRAND SLAM TRANSPORTATION | | | SCAC4 |
| 23 | GSMU | AIR LIQUIDE HEALTHCARE ESPAÑA, S.L. | | E | BIC |
| 24 | GSMU | GASMEDI 2000 S A U | | | SCAC4 |
| 25 | GSMV | GRAEBEL SACRAMENTO MOVERS | | | SCAC4 |
| 26 | GSMW | GULF STATES MARINE SUPPLIES INCORPO | | | SCAC4 |
| 27 | GSMX | GREAT SANDHILLS TERMINAL MARKETING | | | SCAC4 |
