| 1 | GCA | Georgian Cargo Airlines | Callsign: Georgian Cargo, | GE | AVCODES |
| 2 | GCA | Great China Airlines | IATA: GC, Designator GC recalled by IATA | PRC | AVCODES |
| 3 | GCA | Great China Airlines | IATA: IF, Designator IF recalled by IATA | PRC | AVCODES |
| 4 | GCA | UAB Grand Cru Airlines | Callsign: Grand Cru, | LT | AVCODES |
| 5 | GCA | Gran Colombia de Aviacion SAS d/b/a GCA Airlines | IATA: 9A, Founded in June 2017. Subsidiary of the Avior Group. Commenced operations on 29 November 2019. | CO | AVCODES |
| 6 | GCA | Servicios Aereos GECA S.A. d/b/a GECA | IATA: D6, Callsign: Aerogeca, | DOM | AVCODES |
| 7 | GCA | Grampetcargo Austria | | A | TRAFFIC |
| 8 | GCAB | GLOBAL CARGO TRANSPORT INC | | | SCAC4 |
| 9 | GCAC | GULF CARRIER CORP | | | SCAC4 |
| 10 | GCAF | GRIEGER, CHARLES A INC | | | SCAC4 |
| 11 | GCAJ | GALANT CARTAGE | | | SCAC4 |
| 12 | GCAL | GCA LOGISTICS GROUP INC | | | SCAC4 |
| 13 | GCAM | GUENTHER, CARL | | | SCAC4 |
| 14 | GCAN | Gran Canaria | | E | TRAFFIC |
| 15 | GCAO | GEORGETOWN PAPER STOCK OF ROCKVILLE | | | SCAC4 |
| 16 | GCAQ | GARCIA, A TRUCKING | | | SCAC4 |
| 17 | GCAR | GADSDEN CARTAGE COMPANY INC | | | SCAC4 |
| 18 | GCAS | GASCA, JOSE ALBERTO AND GARSCA ESPA | | | SCAC4 |
| 19 | GCAT | GRACE CATTLE CARRIERS INC | | | SCAC4 |
| 20 | GCAU | GCA VRAC TCPL | | F | BIC |
| 21 | GCAU | G.C.A. TRANSPORTS LTD. | | | PWRC |
| 22 | GCAU | G.C.A. Transport | | | RSRV |
| 23 | GCAU | SOLOGAZ | | | SCAC4 |
| 24 | GCAW | GRANDWEST CORP | | | SCAC4 |
| 25 | GCAX | Gaylord Container Corp. | 7/1937 (not listed) | | NAKINA |
| 26 | GCAX | GAYLORD CONTAINER CORP. | | | PWRC |
| 27 | GCAY | GTL CARRIERS | | | SCAC4 |
