| 1 | GSP | Airlift Alaska | Callsign: Green Speed, | USA | AVCODES |
| 2 | GSP | Global Flight School | Callsign: Global School, | P | AVCODES |
| 3 | GSP | Airlift Alaska | | | ICAO1 |
| 4 | GSP | GULF STATES POWER | | | PWRC |
| 5 | GSPC | GREATER SHIPPING CO LTD | | | SCAC4 |
| 6 | GSPE | GLOBAL SUPPLY TRANSPORTATION SOLUTI | | | SCAC4 |
| 7 | GSPI | GROUPE SCULNICK TRANSPORTATION | | | SCAC4 |
| 8 | GSPK | GOLD SPUR TRUCKING LLC | | | SCAC4 |
| 9 | GSPM | GARDEN STATE ASPHALT MATERIALS INC | | | SCAC4 |
| 10 | GSPN | GASPERSON TRANSFER | | | SCAC4 |
| 11 | GSPO | GAN-SPIRIT CO LTD | | | SCAC4 |
| 12 | GSPP | GRANNIS PETROLEUM PRODUCTS INC | | | SCAC4 |
| 13 | GSPT | GENERAL TRANSPORT INC | | | SCAC4 |
| 14 | GSPU | SEACUBE CONTAINERS LLC | | USA | BIC |
| 15 | GSPU | Seacube Container Leasing | | | RSRV |
| 16 | GSPX | Great Southern Plywood Co. | added 7/1975; 1/1980; eliminated 10/1988 | | NAKINA |
| 17 | GSPX | Gaspesia Sulphite Co., Ltd. | 1/1950; 1/1952 (not listed) | | NAKINA |
| 18 | GSPX | Gaspesia Sulphite Co., Ltd. | Jan-52 | | NRHS |
| 19 | GSPX | Great Southern Plywood Co. | added 7/75; 1/80; eliminated 10/88 | | NRHS |
| 20 | GSPX | *GASPESIA SULPHITE CO., LTD. | | | PWRC |
| 21 | GSPX | *GREAT SOUTHERN PLYWOOD CO. | | | PWRC |
| 22 | GSPX | Great Southern Plywood | | | RSRV |
| 23 | GSPY | GMR SPYRIDON LLC | | | SCAC4 |
| 24 | GSPZ | GULF STATES PAPER CO. | | | PWRC |
