| 1 | GPX | GP Aviation E.o.o.d. | IATA: IV, Callsign: Ivory, | BG | AVCODES |
| 2 | GPX | The Glidden Co., Naval Stores Division | 4/1947-4/1961; eliminated 10/1963 | | NAKINA |
| 3 | GPX | Georgia Pine Turpentine Co. | 7/1923-1/1943 | | NAKINA |
| 4 | GPX | Southern Pine Chemical Co., Division of the Glidden Co. | 1/1945-1/1946 | | NAKINA |
| 5 | GPX | Georgia Pine Turpentine Co. of New York | 8/1920 | | NAKINA |
| 6 | GPX | Georgia Pine Turpentine Co. | Apr-38 | | NRHS |
| 7 | GPX | The Glidden Co., Naval Stores Division | 1/52-4/61 | | NRHS |
| 8 | GPX | GLIDDEN CO., NAVAL STORES DIV. [SOUTHERN PINE CHEMICAL CO.; GEORGIA PINE TURPENTINE CO.] | | | PWRC |
| 9 | GPXC | G P EXPRESS | | | SCAC4 |
| 10 | GPXL | G PROULX LLC | | | SCAC4 |
| 11 | GPXQ | GP TRANS INC | | | SCAC4 |
| 12 | GPXS | GP XPRESS | | | SCAC4 |
| 13 | GPXT | G P EXPRESS TRUCKING INC | | | SCAC4 |