| 1 | DI | Deutsche BA Luftfahrtgeselischaft mbH | ICAO: BAG, Callsign: Speedway, IATA Prefix: 944, Name changed to Dba Lufttahrtgesellschaft mbH | D | AVCODES |
| 2 | DI | Delta Air Regionalflugverkhr GmbH | ICAO: DEL, Callsign: Bodensse, Merge into form Deutsche BA | D | AVCODES |
| 3 | DI | Donaldson International Airways | Callsign: Donaldson, | GB | AVCODES |
| 4 | DI | Dba Lufttahrtgesellschaft mbH | ICAO: BAG, Callsign: Speedway, IATA Prefix: 944, Merged into Air Berlin. Name changed from Deutsche BA Luftfahrtgeselischaft mbH | D | AVCODES |
| 5 | DI | Cambodia Airlines Co. Ltd. | ICAO: KHM, Callsign: Cambodia Airlines, IATA designator changed from Y6*. Designator Y6* reinstated by IATA | K | AVCODES |
| 6 | DI | Norwegian Air UK Ltd. | ICAO: NRS, Callsign: Norworld, ICAO Callsign changed to Rednose. | GB | AVCODES |
| 7 | DI | Norwegian Air UK Ltd. | ICAO: NRS, Callsign: Rednose, Ceased operations on 01 November 2021. ICAO Callsign changed from Norworld. | GB | AVCODES |
| 8 | DI | DAKOTA & IOWA RAILROAD | | | PWRC |
| 9 | DI | D.I. Diversified Investments SA | | CH | VKM |
| 10 | DIA | Direct Air, Inc. | Callsign: Blue sky, Designator HB recalled by IATA | USA | AVCODES |
| 11 | DIA | Direct Air, Inc. | IATA: HB, Callsign: Blue sky, Designator HB recalled by IATA | USA | AVCODES |
| 12 | DIA | Direct Air | | | ICAO1 |
| 13 | DIAA | DIAMOND STATE TRUCKING INC | | | SCAC4 |
| 14 | DIAB | DIABLO TRANSPORTATION, INC | | | SCAC1 |
| 15 | DIAB | DI APPOLO TRUCKING LLC | | | SCAC4 |
| 16 | DIAC | DIACON TECHNOLOGIES INC | | | SCAC4 |
| 17 | DIAL | DIAZ, LUIS | | | SCAC4 |
| 18 | DIAM | DIAMOND MATERIALS LLC | | | SCAC4 |
| 19 | DIAMO | DIAMO, státní podnik | | CZ | VKM |
| 20 | DIAN | DIANA TRUCK LINES, INC | | | SCAC1 |
| 21 | DIAN | DIANA TRUCKING CORP | | | SCAC4 |
| 22 | DIAQ | DIXIE ONE TRUCKING LLC | | | SCAC4 |
| 23 | DIAR | DOMESTIC INTERMODAL AMERICA INC | | | SCAC4 |
| 24 | DIAT | DIAMOND TRANSPORTATION SYSTEM, INC | | | SCAC4 |
| 25 | DIAW | DIABLO TRUCKING LLC | | | SCAC4 |
| 26 | DIB | DILLONS BUS SERVICE INC | | | SCAC4 |
| 27 | DIBB | DISTINCTIVE CUSTOM CABINETS CORPORA | | | SCAC4 |
| 28 | DIBE | DIETERS METAL FABRICATING LTD | | | SCAC4 |
| 29 | DIBL | DIBLE, JIM OIL COMPANY INC | | | SCAC4 |
| 30 | DIBQ | DIXON NETWORKS CORPORATION | | | SCAC4 |
| 31 | DIBS | DIAKON LOGISTICS | | | SCAC4 |
| 32 | DIBT | DISTRIBUTORS TRANSPORT INC | | | SCAC4 |
| 33 | DIBU | DESERT ISLE INC. | | USA | BIC |
| 34 | DIBU | HEDE NIELSEN A/S | | | SCAC4 |
| 35 | DIBV | DICKSON BULK SERVICES INC | | | SCAC4 |
| 36 | DIC | Aeromedica, S.A. de C.V. | Callsign: Aeromedica, | MEX | AVCODES |
| 37 | DIC | Aeromedica | | | ICAO1 |
| 38 | DICA | DALPRO INDUSTRIAL CLEANING OF AMERI | | | SCAC4 |
| 39 | DICC | DILLON, C C COMPANY | | | SCAC4 |
| 40 | DICE | DICECO LIMITED ENTERPRISES, INC | | | SCAC1 |
| 41 | DICE | DIAMOND LOGISTICS INC | | | SCAC4 |
| 42 | DICI | DIAMOND COURIER INC | | | SCAC4 |
| 43 | DICL | DIRECT CONTAINER LINES (NVOCC) | | | SCAC1 |
| 44 | DICL | DIRECT CONTAINER LINE INC | | | SCAC4 |
| 45 | DICN | DI CENSO TRANSPORT INC | | | SCAC4 |
| 46 | DICO | DICOSTANZO, G INC | | | SCAC4 |
| 47 | DICR | DI-COR ENGINEERING | | | SCAC4 |
| 48 | DICS | DISCOUNT COURIER SERVICES | | | SCAC4 |
| 49 | DICT | D T L TRANSPORTATION INC | | | SCAC4 |
| 50 | DICV | DIENER INC | | | SCAC4 |
| 51 | DICX | Merchants Despatch Transportation Corp. | 1/1975-1/1980; eliminated 1/1980 | | NAKINA |
| 52 | DICX | Airco Industrial Gases, a Division of Airco, Inc. | added 1/1972; eliminated 4/1973 | | NAKINA |
| 53 | DICX | Airco Industrial Gases, Division Air Reduction Co., Inc. | eliminated 1/1972 | | NAKINA |
| 54 | DICX | Merchants Despatch Transportation Corp. | 4/1970 | | NAKINA |
| 55 | DICX | ""Dry Ice"" Refrigerator Line, Pure Carbonic Co., a Division of Air Reduction Co., Inc. (Merchants Despatch Transportation Corp.) | 10/1966 | | NAKINA |
| 56 | DICX | Merchants Despatch Transportation Corp. | 1/1946-7/1965 | | NAKINA |
| 57 | DICX | Pure Carbonic, Inc. | 1/1941-1/1945 | | NAKINA |
| 58 | DICX | Pure Carbonic, Inc., Refrigerator Line | 4/1938 | | NAKINA |
| 59 | DICX | Dry Ice Corp. of America (Dry Ice Inc., Refrigerator Line) | 7/1937 | | NAKINA |
| 60 | DICX | Dry Ice, Inc./Dry Ice, Inc., Refrigerator Line | 7/1935 | | NAKINA |
| 61 | DICX | Dry Ice Corp. Refrigerator Line | 7/1930-7/1932 | | NAKINA |
| 62 | DICX | Dry Ice Co., Refrigerator Line | Apr-38 | | NRHS |
| 63 | DICX | Merchants Despatch Transportation Corp. | 1/52-7/65 | | NRHS |
| 64 | DICX | "Dry Ice" Refrigerator Line, Pure Carbonic Co., a Division of Air Reduction Co., Inc. (Merchants Despatch Transportation Corp.) | Oct-66 | | NRHS |
| 65 | DICX | Merchants Despatch Transportation Corp. | Apr-70 | | NRHS |
| 66 | DICX | Airco Industrial Gases, Division Air Reduction Co., Inc. | eliminated 1/72 | | NRHS |
| 67 | DICX | Airco Industrial Gases, a Division of Airco, Inc. | added 1/72; eliminated 4/73 | | NRHS |
| 68 | DICX | Merchants Despatch Transportation Corp. | 1/75-1/80; eliminated 1/80 | | NRHS |
| 69 | DICX | *MERCHANTS DESPATCH TRANSPORTATION CORP. | | | PWRC |
| 70 | DICX | *AIRCO INDUSTRIAL GASSES [PURE CARBONIC CO.; DRY ICE CORP. OF AMERICA] | | | PWRC |
| 71 | DICX | Pure Carbonic | | | RSRV |
| 72 | DIDB | DAISHIN SHIPPING CO LTD | | | SCAC4 |
| 73 | DIDI | DHT LOGISTICS LLC | | | SCAC4 |
| 74 | DIDP | DEPENDABLE EXPRESS FREIGHT | | | SCAC4 |
| 75 | DIDQ | DRAEGER OIL COMPANY INC | | | SCAC4 |
| 76 | DIDT | DETROIT INTERMODAL TRANSPORT INC | | | SCAC4 |
| 77 | DIDU | BERTSCHI AG | | CH | BIC |
| 78 | DIDU | BERTSCHI AG | | | SCAC4 |
| 79 | DIE-LEI | DIE-LEI GmbH | Kassel (Die-Lei abgeleitet von Dienstleistung) | D | privat-bahn.de |
| 80 | DIEA | DIERA MARITIME INC | | | SCAC4 |
| 81 | DIEB | DOUBLE B S TRUCKING | | | SCAC4 |
| 82 | DIEBM | Die Bahnmeisterei | | DE | VKM |
| 83 | DIEC | DIRECT EXPRESS COURIER SERVICES INC | | | SCAC4 |
| 84 | DIED | DIEMER, ED TRUCKING CO INC | | | SCAC4 |
| 85 | DIEH | DAIGLE & HOUGHTON INC | | | SCAC4 |
| 86 | DIEI | DAHER IMPORT EXPORT INC | | | SCAC4 |
| 87 | DIENO | Dieselnostalgie Schienenfahrzeugbereitstellungs GmbH | | AT | VKM |
| 88 | DIEV | DICKS MOVING INC | | | SCAC4 |
| 89 | DIEY | DOUBLE I EXPRESS | | | SCAC4 |
| 90 | DIFC | DIFCO INC | | | SCAC4 |
| 91 | DIFN | D I F INC | | | SCAC4 |
| 92 | DIFS | DIAMOND FREIGHT SYSTEMS INC | | | SCAC4 |
| 93 | DIFU | DOLE FRESH FRUIT INTERNATIONAL LTD | | | SCAC4 |
| 94 | DIFW | DYNASTY INTL FORWARDING INC | | | SCAC4 |
| 95 | DIG | DAC International Airlines Ltd. d/b/a PassionAir | IATA: OP, Callsign: Dac Air, | GH | AVCODES |
| 96 | DIGG | DIGGER SPECIALTIES INC | | | SCAC4 |
| 97 | DIGN | DESIGN ORIGINAL INC | | | SCAC4 |
| 98 | DIGP | DIGIPOS STORE SOLUTIONS | | | SCAC4 |
| 99 | DIGS | DIGGS, C D TRUCKING INC | | | SCAC4 |
| 100 | DIGU | DIG AIRGAS CO, Ltd. | | ROK | BIC |
