| 1101 | GCOH | GIRAN CORPORATION | | | SCAC4 |
| 1102 | GCOI | GATEWEST STAMP & COIN LTD | | | SCAC4 |
| 1103 | GCOK | GILCO TRUCKING COMPANY INC | | | SCAC4 |
| 1104 | GCOM | GRACE OIL COMPANY INC | | | SCAC4 |
| 1105 | GCOQ | GASCO ENERGY SUPPLY LLC | | | SCAC4 |
| 1106 | GCOS | GILB TRUCKING LLC | | | SCAC4 |
| 1107 | GCOU | GASCO N V | | | SCAC4 |
| 1108 | GCOX | The Gold Coast Railroad Museum Inc. | 7/2005 (not listed) | | NAKINA |
| 1109 | GCOX | Gulf Oil Products Co., Division of Gulf Oil Corp. | eliminated 7/1985 | | NAKINA |
| 1110 | GCOX | Miller Compressing Co. | added 10/1964; 7/1965-4/1970; eliminated 1/1973 | | NAKINA |
| 1111 | GCOX | Miller Compressing Co. | 7/65-4/70; eliminated 1/73 | | NRHS |
| 1112 | GCOX | *MILLER COMPRESSING CO. [RETIRED 10-28-93 ATP] | | | PWRC |
| 1113 | GCOX | *GULF OIL PRODUCTS CO. DIV. GULF OIL CORP. | | | PWRC |
| 1114 | GCOX | +GOLD COAST RAILROAD MUSEUM, INC. | | | PWRC |
| 1115 | GCOX | Gold Coast Railroad Museum | | | RSRV |
| 1116 | GCOX | GOLD COAST RAILROAD MUSEUM INC, THE | | | SCAC4 |
| 1117 | GCOZ | GREENWAY CO-OP | | | PWRC |
| 1118 | GCP | DAC Air, S.A. | IATA: 6P, Ceased operations | RO | AVCODES |
| 1119 | GCPD | GLENN CO PRODUCE DISTRIBUTORS INC | | | SCAC4 |
| 1120 | GCPI | GARFIELD CONTAINER TRANSPORT INC | | | SCAC4 |
| 1121 | GCPR | GREAT CONCEPTS INC | | | SCAC4 |
| 1122 | GCPU | BURLINGTON NORTHERN AND SANTA FE RAILWAY (BNSF RAILWAY) [GENSTAR CONTAINER CORPORATION] | | | PWRC |
| 1123 | GCPU | Genstar (BNSF Railway) | | | RSRV |
| 1124 | GCPV | Cementos Portland Valderrivas, S.A. | | ES | VKM |
| 1125 | GCPX | Georgia Gulf Corp., PVC Division | added 4/1985; 1/1994-7/2005 | | NAKINA |
| 1126 | GCPX | Georgia Pacific Chemicals, Inc. | added 10/1984; eliminated 4/1985 | | NAKINA |
| 1127 | GCPX | Georgia Pacific Chemicals, Inc. | added 10/84; eliminated 4/85 | | NRHS |
| 1128 | GCPX | Georgia Gulf Corp., PVC Division | added 4/85; 1/94-7/2000 | | NRHS |
| 1129 | GCPX | GEORGIA GULF CORP., PVC DIV.[GEORGIA PACIFIC CHEMICALS] | | | PWRC |
| 1130 | GCPX | Georgia Gulf Corporation (PVC Division) | | | RSRV |
| 1131 | GCPX | GEORGIA GULF CORP., PVC DIV. | | | SCAC4 |
| 1132 | GCQE | GARCIA QUINTANILLA, EMILIO | | | SCAC4 |
| 1133 | GCQI | GC LOGISTICS INC | | | SCAC4 |
| 1134 | GCQZ | GRANITE CANYON QUARRY | | | PWRC |
| 1135 | GCR | Cougar Leasing Limited. | Callsign: Speedcat, Suspended operations on 17 May 2003. | GB | AVCODES |
| 1136 | GCR | Grand China Express Co. Ltd. | IATA: GS, IATA Prefix: 826, Name changed to Tianjin Airlines Co. Ltd | PRC | AVCODES |
| 1137 | GCR | Tianjin Airlines Co. Ltd | IATA: GS, Callsign: China Dragon, IATA Prefix: 826, Name changed from Grand China Express Co. Ltd. ICAO Callsign changed to Bo Hai | PRC | AVCODES |
| 1138 | GCR | Tianjin Airlines Co. Ltd | IATA: GS, Callsign: Bo Hai, IATA Prefix: 826, Name changed from Grand China Express Co. Ltd. ICAO Callsign changed from China Dragon. | PRC | AVCODES |
| 1139 | GCR | GOLD COAST RAILWAY | | | PWRC |
| 1140 | GCR | Great Central Railway | | GB | TRAFFIC |
| 1141 | GCRAL | Transportes Hermanos Cortés, S.L | | ES | VKM |
| 1142 | GCRC | The Golden Cat R.R. Corp. | added 7/1988; eliminated 4/1989; added 7/1991; 1/1994; eliminated 1/1995 | | NAKINA |
| 1143 | GCRC | The Golden Cat R.R. Corp. | added 7/88; eliminated 4/89; added 7/91; 1/94; eliminated 1/95 | | NRHS |
| 1144 | GCRC | GOLDEN CAT RAILROAD CORP. | | | PWRC |
| 1145 | GCRC | GOLDEN CAT RAILROAD CORP, THE | | | SCAC4 |
| 1146 | GCRG | GOLD COAST RACING INC & GSR TRANSPO | | | SCAC4 |
| 1147 | GCRI | GOLDEN CARRIERS INC | | | SCAC4 |
| 1148 | GCRM | GANASSI, CHIP RACING TEAMS INC | | | SCAC4 |
| 1149 | GCRN | GILL CARRIER INC | | | SCAC4 |
| 1150 | GCRR | GRAHAM COUNTY RAILROAD | | | PWRC |
| 1151 | GCRR | GUERRERO CRUZ, ROLANDO | | | SCAC4 |
| 1152 | GCRR | Georgia Central Ry. | Real: GC | USA | TRAFFIC |
| 1153 | GCRS | GROCERS SUPPLY COMPANY INC | | | SCAC4 |
| 1154 | GCRT | GENERAL CRANE AND TRUCKING SERVICE, INC | | | SCAC1 |
| 1155 | GCRTA | Greater Cleveland Regional Transit Authority | | USA | TRAFFIC |
| 1156 | GCRU | GARDNER CRYOGENICS | | USA | BIC |
| 1157 | GCRU | Gardner Cryogenics | | | RSRV |
| 1158 | GCRU | GARDNER CRYOGENICS | | | SCAC4 |
| 1159 | GCRV | GIANT COLORFUL REVOLUTION LLC | | | SCAC4 |
| 1160 | GCRX | Grand Canyon Ry., Inc. | 7/2000-7/2005 (not listed) | | NAKINA |
| 1161 | GCRX | General American Transportation Corp. | added 4/1968; 4/1970-1/1975; eliminated 7/1975; 1/1980 | | NAKINA |
| 1162 | GCRX | Grand Canyon Ry., Inc. | Jul-00 | | NRHS |
| 1163 | GCRX | General American Transportation Corp. | added 4/68; 4/70-1/75; eliminated 7/75; 1/80 | | NRHS |
| 1164 | GCRX | *GENERAL AMERICAN TRANSPORTATION CORP. | | | PWRC |
| 1165 | GCRX | +GRAND CANYON RAILWAY | | | PWRC |
| 1166 | GCRX | Grand Canyon Railway | | | RSRV |
| 1167 | GCRX | GRAND CANYON RAILWAY INC | | | SCAC4 |
| 1168 | GCRX | Grand Canyon Railway | | USA | TRAFFIC |
| 1169 | GCRY | GRAND CANYON RAILWAY | | | PWRC |
| 1170 | GCRY | GULF COAST RELOCATION SYSTEMS INC | | | SCAC4 |
| 1171 | GCS | GCS Air Service, Inc. | Callsign: Galion, Name changed from Galion Crestline Service | USA | AVCODES |
| 1172 | GCS | Galion Crestline Service | Callsign: Galion, Name changed to GCS Air Service | USA | AVCODES |
| 1173 | GCS | Skyway Airline | Callsign: Sky Tec, | CR | AVCODES |
| 1174 | GCS | GCS Air Service | | | ICAO1 |
| 1175 | GCS | GEMINI CHARTER SERVICE | | | SCAC4 |
| 1176 | GCSF | GULF, COLORADO & SANTA FE RAILWAY | | | PWRC |
| 1177 | GCSF | Gulf, Colorado and Santa Fe Railway | | | RSRV |
| 1178 | GCSI | GCS INTERMODAL LLC | | | SCAC4 |
| 1179 | GCSK | GUTCO CONSTRUCTORA SA DE CV | | | SCAC4 |
| 1180 | GCSR | Gulf, Colorado & San Saba Ry. | 1/1994-7/2000 | | NAKINA |
| 1181 | GCSR | Gulf, Colorado & San Saba Ry. | 1/94-7/2000 | | NRHS |
| 1182 | GCSR | GULF, COLORADO & SAN SABA RAILWAY | | | PWRC |
| 1183 | GCSR | Gulf, Colorado and San Saba Railway | | | RSRV |
| 1184 | GCSR | GULF COLORADO & SAN SABA RAILWAY | | | SCAC4 |
| 1185 | GCST | GULFCOAST LOGISITCS | | | SCAC4 |
| 1186 | GCSU | PEACOCK CONTAINER PTE. LTD. | | SGP | BIC |
| 1187 | GCSU | G.C.S. CONTAINERS SERVICE SA | | | PWRC |
| 1188 | GCSU | G.C.S. Containers Service | | | RSRV |
| 1189 | GCSU | GRAND CHINA SHIPPING HONG KONG COMP | | | SCAC4 |
| 1190 | GCSX | Gulf, Colorado & San Sabe Ry. | 7/2005 | | NAKINA |
| 1191 | GCSX | Granite City Steel Co. | 7/1930-1/1941; 1/1943-4/1961 (not listed) | | NAKINA |
| 1192 | GCSX | Granite City Steel Co. | 4/38-4/61 | | NRHS |
| 1193 | GCSX | *GRANITE CITY STEEL CO. | | | PWRC |
| 1194 | GCSX | *GULF, COLORADO & SAN SABA RWY. | | | PWRC |
| 1195 | GCSX | RAIL LOGISTICS SERVICES INC | | | SCAC4 |
| 1196 | GCSY | GARCIA, SAMUEL | | | SCAC4 |
| 1197 | GCSZ | GULF CENTRAL SYSTEMS | | | PWRC |
| 1198 | GCT | GC Aviation, Inc | Callsign: Gulf Coast, Merged in Volato, Inc. (TMB) | USA | AVCODES |
| 1199 | GCTB | G & C TRANSPORTATION INC | | | SCAC4 |
| 1200 | GCTC | G & C TRUCKING INC | | | SCAC4 |
