| 401 | DARZ | Dart Intermodal | | | RSRV |
| 402 | DARZ | DART INTERMODAL INC | | | SCAC4 |
| 403 | DAS | Dialogue-S-Aero | Callsign: Dialogue, | KZ | AVCODES |
| 404 | DAS | Dollar Helicopters | Callsign: Dollar, | GB | AVCODES |
| 405 | DAS | Dollar Air Services Ltd. | Callsign: Dollar, | GB | AVCODES |
| 406 | DAS | Damascene Airways | | | ICAO1 |
| 407 | DASB | DAVIS, BILL TRUCKING INC | | | SCAC4 |
| 408 | DASC | D A S CARGO PT | | | SCAC4 |
| 409 | DASD | DASH LOGISTICS INC | | | SCAC4 |
| 410 | DASG | DAS GLOBAL SERVICES INC | | | SCAC4 |
| 411 | DASJ | DAS GLOBAL SERVICES | | | SCAC4 |
| 412 | DASS | DAS TRUCKING INC | | | SCAC4 |
| 413 | DAST | DAVES AIRPORT SHUTTLE | | | SCAC4 |
| 414 | DASU | ALROSA COMPANY LIMITED | | | SCAC4 |
| 415 | DASV | DIRECT AIR SERVICE INC | | | SCAC4 |
| 416 | DASY | DAISY CONSTRUCTION COMPANY | | | SCAC4 |
| 417 | DAT | Delta Air Transport N.V. | IATA: SN, Callsign: Deltair, IATA Prefix: 082, Name changed to SN Brussels Airlines. IATA designator changed from QG, ICAO designator changed from DAT | B | AVCODES |
| 418 | DAT | Delta Air Transport (D.A.T.) | IATA: QG, Callsign: Deltair, IATA designator changed to SN, ICAO designator changed to SAB | B | AVCODES |
| 419 | DAT | Delta Air Transport N.V. d/b/a SN Brussels Airlines | IATA: SN, Callsign: Estail, IATA Prefix: 082, Name changed from Delta Air Transport N.V. w.e.f. 15 February 2002. IATA designator changed from QG, ICAO designator changed from DAT | B | AVCODES |
| 420 | DAT | Delta Air Transport (D.A.T.) | IATA: DE, Callsign: Deltair, IATA designator changed to QG | B | AVCODES |
| 421 | DAT | Delta Air Transport N.V. t/a Brussels Airlines | IATA: SN, Callsign: Estail, IATA Prefix: 082, Name changed from Delta Air Transport N.V. d/b/a SN Brussels Airlines. IATA designator changed from QG, ICAO designator changed from DAT | B | AVCODES |
| 422 | DAT | Brussels Airlines N.V. | IATA: SN, Callsign: Estail, IATA Prefix: 082, ICAO Desginator changed to BEL. Name changed from Delta Air Transport N.V. t/a Brussels Airlines. IATA designator changed from QG, ICAO designator changed from DAT | B | AVCODES |
| 423 | DAT | Brussels Airlines N.V. | IATA: SN, Callsign: Bee-Line, IATA Prefix: 082, ICAO Desginator changed to BEL. Name changed from Delta Air Transport N.V. t/a Brussels Airlines. IATA designator changed from QG, ICAO designator changed from DAT | B | AVCODES |
| 424 | DAT | Dart Limited Trust Distribution | IATA: D4, Callsign: Dartlimited, Suspended operations during February 2018. Assets requested to be transferred to new airline called LLC Alanna. | UA | AVCODES |
| 425 | DAT | 1263343 Alberta Inc t/a Enerjet | IATA: Y9, Callsign: Dauntless, Name changed to 1263343 Alberta Inc t/a Lynx Air. | CDN | AVCODES |
| 426 | DAT | 1263343 Alberta Inc t/a Lynx Air | IATA: Y9, Callsign: Dauntless, Name changed from 1263343 Alberta Inc t/a Enerjet. | CDN | AVCODES |
| 427 | DAT | Brussels Airlines | IATA: SN | | ICAO1 |
| 428 | DATA | D-A TRANSPORTATION COMPANY LLC | | | SCAC4 |
| 429 | DATB | D & A TRANSPORT | | | SCAC4 |
| 430 | DATD | DOUBLE A TRANSPORT LLC | | | SCAC4 |
| 431 | DATF | DUPASQUIER, ANDRE TRUCKING | | | SCAC4 |
| 432 | DATG | DALES TRUCKING | | | SCAC4 |
| 433 | DATH | DALOR TRANSIT INC | | | SCAC4 |
| 434 | DATI | DAILY-SELECT (DIVISION OF TFI TRANS | | | SCAC4 |
| 435 | DATK | DAVIS EXPRESS INC | | | SCAC4 |
| 436 | DATN | D & A TRUCKING | | | SCAC4 |
| 437 | DATT | DAT TRUCKING | | | SCAC4 |
| 438 | DATU | DART CONTAINER LINE INC. | | | PWRC |
| 439 | DATU | Dart Container Line | | | RSRV |
| 440 | DATW | D & A TRANSPORT | | | SCAC4 |
| 441 | DATX | DATX Associates | added 7/1985; 1/1994-7/2005 | | NAKINA |
| 442 | DATX | DATX Associates | 1/94-7/2000 | | NRHS |
| 443 | DATX | DATX ASSOCIATES | | | PWRC |
| 444 | DATX | DATX Associates | | | RSRV |
| 445 | DATX | DATX ASSOCIATES | | | SCAC4 |
| 446 | DATZ | DATSUN | | | PWRC |
| 447 | DAU | Dau Air Verwaltungs AG | IATA: D5, Callsign: Dauair, Ceased operations on 16 August 2006. | D | AVCODES |
| 448 | DAU | Dauair | IATA: D5 | | ICAO1 |
| 449 | DAU | Dau Eisenbahn-Straßen und Tiefbau GmbH | | DE | VKM |
| 450 | DAUF | DAUFELDT TRANSPORT INC | | | SCAC4 |
| 451 | DAUGS | Daugavpils Satiksme | City: Daugavpils | LV | TRAFFIC |
| 452 | DAUL | DAUL, W. N | | | SCAC1 |
| 453 | DAUM | DAUM LLC | | | SCAC4 |
| 454 | DAUP | DEAL AUTO TRANSPORT | | | SCAC4 |
| 455 | DAUS | DONS AUTO SALES & TRANSPORT | | | SCAC4 |
| 456 | DAUT | DEPENDABLE AUTO TRANSPORT LLC | | | SCAC4 |
| 457 | DAV | Dornier Aviation Nigeria Aiep Ltd. | IATA: DO, Callsign: Dana, Designator DO* recalled by IATA | WAN | AVCODES |
| 458 | DAV | Dirac Aviation | IATA: YM, Callsign: Dirac, | F | AVCODES |
| 459 | DAV | Dana Airlines Ltd. | Callsign: Dana Air, ICAO code changed to DAN | WAN | AVCODES |
| 460 | DAV | Dornier Aviation Nigeria Aiep Ltd. | IATA: DO, Callsign: Dana, Designator DO* recalled by IATA | WAN | AVCODES |
| 461 | DAV | Dornier Aviation Nigeria | | | ICAO1 |
| 462 | DAVA | DANIVA INC | | | SCAC4 |
| 463 | DAVC | DAVIESS COUNTY TRUCKING INC | | | SCAC4 |
| 464 | DAVD | DAVIDOV TRANSPORT | | | SCAC4 |
| 465 | DAVE | DAVES FUEL | | | SCAC4 |
| 466 | DAVG | DAVENPORT TRANSPORT & RIGGING LLC | | | SCAC4 |
| 467 | DAVK | DAVIDSON TRUCKING INC | | | SCAC4 |
| 468 | DAVM | DAVIS PETROLEUM INC | | | SCAC4 |
| 469 | DAVV | DAVIS COMPANY INC | | | SCAC4 |
| 470 | DAVX | W.R. Grace & Co.-Conn. Davison Chemical Division | added 10/1989; 1/1994; eliminated 7/1997; 7/2000-7/2005 (not listed) | | NAKINA |
| 471 | DAVX | W.R. Grace & Co.-Conn. Davison Chemical Division | added 10/89; 1/94; eliminated 7/97; 7/2000 | | NRHS |
| 472 | DAVX | W. R. GRACE & COMPANY - CONN. DAVISON CHEMICAL DIV. | | | PWRC |
| 473 | DAVX | W. R. Grace Conn. Davison Chemical Division | | | RSRV |
| 474 | DAVX | W. R. GRACE & COMPANY - | | | SCAC4 |
| 475 | DAW | Duo Airways Limited | IATA: VB, Callsign: Fly Duo, IATA Prefix: 702, ICAO code changed from MSK. ICAO Callsign changed to from Bluestar. Name changed from Maersk Air Ltd. | GB | AVCODES |
| 476 | DAW | Centrala Obrotu Towarami Masowymi DAW-BYTOM Sp. z o.o. | | PL | VKM |
| 477 | DAWB | DAWG LOGISTICS SERVICES | | | SCAC4 |
| 478 | DAWG | DAWG ENTERPRISE INC | | | SCAC4 |
| 479 | DAWH | DAWE HUESCA, MIGUEL ANGEL | | | SCAC4 |
| 480 | DAWI | DAWES TRANSPORT, INC | | | SCAC1 |
| 481 | DAWI | DAWES TRANSPORT INC | | | SCAC4 |
| 482 | DAWL | DAW LOGISTICS INC | | | SCAC4 |
| 483 | DAWO | DAWSON OIL CO INC | | | SCAC4 |
| 484 | DAWP | DALYS WOOD PRODUCTS | | | SCAC4 |
| 485 | DAWR | DAWNLEE TRUCKING INC | | | SCAC4 |
| 486 | DAWT | DAWN TRANSPORTATION INC | | | SCAC4 |
| 487 | DAWU | VITERRA UK LTD | | GB | BIC |
| 488 | DAWW | DAWSON ROAD TRANSFER | | | SCAC4 |
| 489 | DAWX | D.A. Walmsley & Co. | 7/2000-7/2005 (not listed) | | NAKINA |
| 490 | DAWX | D.A. Walmsley & Co. | Jul-00 | | NRHS |
| 491 | DAWX | DAVID A. WALMSLEY (D. A. WAMSLEY & CO.) | | | PWRC |
| 492 | DAWX | D.A. Walmsley and Company | | | RSRV |
| 493 | DAWX | D A WALMSLEY & CO | | | SCAC4 |
| 494 | DAX | Aalborg Airtaxi ApS | Callsign: Dantax, | DK | AVCODES |
| 495 | DAX | Occidental Chemical Corp. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 496 | DAX | Occidental Chemical Corp., Electrochemicals & Specialty Products | added 10/1989; eliminated 1/1992 | | NAKINA |
| 497 | DAX | Occidental Chemical Corp., Electrochemicals, Detergents & Specialty Products | added 1/1988; eliminated 10/1989 | | NAKINA |
| 498 | DAX | Occidental Chemical Corp., Electrochemicals, Detergents & Specialty Products Group | added 7/1987; eliminated 1/1988 | | NAKINA |
| 499 | DAX | Diamond Shamrock Chemicals Co. | added 1/1984; eliminated 7/1987 | | NAKINA |
| 500 | DAX | Diamond Shamrock Corp. | added 4/1968; 4/1970-1/1980; eliminated 1/1984 | | NAKINA |
