| 1101 | DCSU | Delta Conteneur Service | | | RSRV |
| 1102 | DCSU | DANISH CONTAINER SUPPLY | | | SCAC4 |
| 1103 | DCSW | DIXIE CLEAN & SWEEP LLC | | | SCAC4 |
| 1104 | DCSZ | MAERSK EQUIPMENT SERVICE COMPANY | | | SCAC4 |
| 1105 | DCT | Directflight Limited. | Callsign: Airtask, | GB | AVCODES |
| 1106 | DCT | Direct Flight | | | ICAO1 |
| 1107 | DCT | DC TRAILS INC | | | SCAC4 |
| 1108 | DCTA | D/C TRUCKING | | | SCAC4 |
| 1109 | DCTB | DOUBLE C TRUCKING LLC | | | SCAC4 |
| 1110 | DCTC | D C TRANSPORT | | | SCAC4 |
| 1111 | DCTE | DRACO TRANSFER | | | SCAC4 |
| 1112 | DCTF | D & C TRUCKING | | | SCAC4 |
| 1113 | DCTG | D C TRUCKING | | | SCAC4 |
| 1114 | DCTH | DCT CHAMBERS USA LTD | | | SCAC4 |
| 1115 | DCTI | DAIMLERCHRYSLER TRANSPORT INC (CANA | | | SCAC4 |
| 1116 | DCTM | DOUCET MACHINERIES INC | | | SCAC4 |
| 1117 | DCTO | DELTA CUSTOM TOOLS | | | SCAC4 |
| 1118 | DCTP | DC TRANSPORT INC | | | SCAC4 |
| 1119 | DCTQ | D C TRANSPORT INC | | | SCAC4 |
| 1120 | DCTR | DC TRANSPORT | | | SCAC4 |
| 1121 | DCTR | DC Transit | City: Washington D.C. | USA | TRAFFIC |
| 1122 | DCTS | D & C TRANSPORTATION INC | | | SCAC4 |
| 1123 | DCTU | BERTSCHI AG | | CH | BIC |
| 1124 | DCTU | DC BALTIC LTD | | | SCAC4 |
| 1125 | DCTW | DEALERS CHOICE TRUCKAWAY SYSTEM INC | | | SCAC4 |
| 1126 | DCTX | The CIT Group/Capital Finance, Inc. | added 1/2006 | | NAKINA |
| 1127 | DCTX | PLM International, Inc. | added 4/1991; 1/1994-7/2005; eliminated 1/2006 | | NAKINA |
| 1128 | DCTX | PLM Railcar Management Services Canada Ltd. | added 1/1987; eliminated 4/1991 | | NAKINA |
| 1129 | DCTX | PLM Railcar Management Services Canada Ltd. | added 1/87; eliminated 4/91 | | NRHS |
| 1130 | DCTX | PLM International, Inc. | added 4/91; 1/94-7/2000 | | NRHS |
| 1131 | DCTX | THE CIT GROUP/CAPITAL FINANCE, INC. [(PLMX) PLM INTERNATIONAL, INC.] | | | PWRC |
| 1132 | DCTX | PLM International | | | RSRV |
| 1133 | DCTX | CIT GROUP/CAPITAL FINANCE INC, THE | | | SCAC4 |
| 1134 | DCTY | DAIICHI CHUO KISEN KAISHA | | | SCAC4 |
| 1135 | DCUI | DAMCO USA INC | | | SCAC4 |
| 1136 | DCV | Discover Air | Callsign: Discover, Suspended operations on 27 March 2003. | USA | AVCODES |
| 1137 | DCV | Discovery Airways Limited t/a DiscoveryAir | IATA: DO, Callsign: Discovery Jet, Designator DO recalled by IATA | WAN | AVCODES |
| 1138 | DCV | Discover Air | | | ICAO1 |
| 1139 | DCVE | DISTINCTIVE TRUCKING LLC | | | SCAC4 |
| 1140 | DCVS | DISCOVER TRANSPORT SERVICES INC | | | SCAC4 |
| 1141 | DCVU | DONGGUAN CIMC VEHICLE CO., LTD. | | PRC | BIC |
| 1142 | DCW | DC Aviation (Malta) Limited | Callsign: Malta Star, | M | AVCODES |
| 1143 | DCWP | DRAFT CARGOWAYS INDIA PRIVATE LIMIT | | | SCAC4 |
| 1144 | DCWX | Detroit Chemical Works, Division of Pressure Vessel Service, Inc. | added 10/1969; 4/1970; eliminated 1/1975 | | NAKINA |
| 1145 | DCWX | W.R. Grace & Co., Davison Chemical Division, Detroit Chemical Works | added 10/1963; 7/1965-10/1966; eliminated 10/1969 | | NAKINA |
| 1146 | DCWX | Detroit Chemical Works | 7/1937-1/1941 (not listed); 1/1943-4/1961; eliminated 10/1963 | | NAKINA |
| 1147 | DCWX | Detroit Chemical Works | 1/52-4/61 | | NRHS |
| 1148 | DCWX | W.R. Grace & Co., Davison Chemical Division, Detroit Chemical Works | 7/65-10/66; eliminated 10/69 | | NRHS |
| 1149 | DCWX | Detroit Chemical Works, Division of Pressure Vessel Service, Inc. | added 10/69; 4/70; eliminated 1/75 | | NRHS |
| 1150 | DCWX | DETROIT CHEMICAL WORKS (DIV. PRESSURE VESSEL SERVICE, INC. PREVIOUSLY DIV. W.R. GRACE & CO.] | | | PWRC |
| 1151 | DCX | Daimler-Chrysler, Inc. | Callsign: Daimler, | USA | AVCODES |
| 1152 | DCX | Daimler-Chrysler | | | ICAO1 |
| 1153 | DCX | Diamond Alkali Co. of California | 1/1952-7/1954; eliminated 7/1956 | | NAKINA |
| 1154 | DCX | Diamond Alkali Co. of California | 1/52; eliminated 7/56 | | NRHS |
| 1155 | DCX | DIAMOND ALKALI OF CALIFORNIA | | | PWRC |
| 1156 | DCXE | DEC EXPRESS | | | SCAC4 |
| 1157 | DCXI | DCX INC | | | SCAC4 |
| 1158 | DCXL | DOUBLE C TRANSPORTS LLC | | | SCAC4 |
| 1159 | DCXN | DEALERS CHOICE TRANSPORT INTERNATIO | | | SCAC4 |
| 1160 | DCXO | D & C TRANSPORT | | | SCAC4 |
| 1161 | DCXR | DC EXPRESS | | | SCAC4 |
| 1162 | DCXT | DOMESTIC TRANSPORT INC | | | SCAC4 |
| 1163 | DCXU | NOURYON PPC AB | | S | BIC |
| 1164 | DCXU | EKA CHEMICALS AB | | | SCAC4 |
| 1165 | DCY | Inversiones Y Promociones Ducoy, S.L. | Callsign: Ducoy, | E | AVCODES |
| 1166 | DCYE | DISCOVERY EXPRESS | | | SCAC4 |
| 1167 | DCYL | DISCOVERY TRANSPORT LLC | | | SCAC4 |
| 1168 | DCYT | DALY CITY TRANSPORT INC | | | SCAC4 |
| 1169 | DCZ | DAVIDSON CHEMICAL | | | PWRC |
| 1170 | DCZI | DEVINCENZI TRUCKING, INC | | | SCAC1 |
| 1171 | DCZI | DEVINCENZI TRUCKING INC | | | SCAC4 |
| 1172 | DCZO | DICENZO, THOMAS INC | | | SCAC4 |
| 1173 | DD | Atlantic Coast Jet, Inc. | ICAO: PRT, Callsign: Patriot, IATA Prefix: 949, IATA designator changed to DD | USA | AVCODES |
| 1174 | DD | Aerolyon | ICAO: AEY, IATA designator changed to 4Q | F | AVCODES |
| 1175 | DD | Contiflug GmbH | | D | AVCODES |
| 1176 | DD | Amber Airways | ICAO: ABM, | GB | AVCODES |
| 1177 | DD | Georgian Bay Airways Limited | | CDN | AVCODES |
| 1178 | DD | Bayu Indonesia Air P.T. | ICAO: BYU, Callsign: Bayu, Designator DD recalled by IATA | RI | AVCODES |
| 1179 | DD | Atlantic Coast Jet, Inc. | ICAO: PRT, Callsign: Patriot, IATA Prefix: 949, Desigantor DD recalled by IATA. IATA designator changed from DD* | USA | AVCODES |
| 1180 | DD | Sky Asia Co. Ltd. d/b/a Nok Air | ICAO: NOK, Name changed to Nok Airlines Co., Ltd. w.e.f. 18 January 2013 | T | AVCODES |
| 1181 | DD | Nok Airlines Company Limited | ICAO: NOK, Callsign: Nok Air, Sky Asia Co. Ltd. d/b/a Nok Air w.e.f. 16 Janaury 2006. Name changed to Nok Airlines Public Co., Ltd. d/b/a Nok Air w.e.f. 18 January 2013. | T | AVCODES |
| 1182 | DD | Nok Airlines Public Co., Ltd. d/b/a Nok Air | ICAO: NOK, Callsign: Nok Air, Filed for bankruptcy on 30 July 2020. Name changed from Nok Airlines Company Limited w.e.f. 18 January 2013 | T | AVCODES |
| 1183 | DD | D&D Eisenbahngesellschaft mbH | | D | TRAFFIC |
| 1184 | DDA | D & D Aviaion | Callsign: Dusty, | USA | AVCODES |
| 1185 | DDA | D & D Aviation | | | ICAO1 |
| 1186 | DDAB | DAVIDSON, DOUG TRUCKING LLC | | | SCAC4 |
| 1187 | DDAD | D & D TRUCKING | | | SCAC4 |
| 1188 | DDAG | DHL GLOBAL | | | SCAC4 |
| 1189 | DDAH | DH-DHEKELIA SHIPMANAGEME | | | SCAC4 |
| 1190 | DDAK | D & D TRUCKING INC | | | SCAC4 |
| 1191 | DDAL | DOCKENDALE SHIPPING COMPANY LTD | | | SCAC4 |
| 1192 | DDAM | DOUBLE DIAMOND TRANSPORT INC | | | SCAC4 |
| 1193 | DDAN | DUTTON, DAN RHONDA | | | SCAC4 |
| 1194 | DDAO | D & D TALBOT INC | | | SCAC4 |
| 1195 | DDAR | DANS DAIRY LLC | | | SCAC4 |
| 1196 | DDAW | DAWNS DAWGS | | | SCAC4 |
| 1197 | DDBA | D & D BROKERAGE | | | SCAC4 |
| 1198 | DDBB | DANIELS, DALE B | | | SCAC4 |
| 1199 | DDBE | D D B ENTERPRISES | | | SCAC4 |
| 1200 | DDBP | DIRECT DISTRIBUTION & TRANSPORTATIO | | | SCAC4 |
