| 1 | HD | Hokkaido International Airlines Co., Ltd. | ICAO: ADO, Callsign: Air Do, Name changed to Air Do Co., Ltd. | J | AVCODES |
| 2 | HD | New York Helicopters Corp. | ICAO: NYH, Callsign: New York, Designator HD recalled by IATA | USA | AVCODES |
| 3 | HD | Aeroservicios S.r.l. | | HN | AVCODES |
| 4 | HD | Air Holland | ICAO: AHD, Callsign: Air Holland, Founded in 1984. Commenced operations in 1985. Suspended all operations in December 1991. ICAO callsign changed to Orange | NL | AVCODES |
| 5 | HD | Air Holland | ICAO: AHD, Callsign: Orange, Founded in 1984. Commenced operations in 1985. Suspended all operations in December 1991. ICAO callsign changed from Air Holland | NL | AVCODES |
| 6 | HD | Air Do Co., Ltd. | ICAO: ADO, Callsign: Air Do, Name changed from Hokkaido International Airlines Co., Ltd. | J | AVCODES |
| 7 | HD | Holger Dietz | | DE | VKM |
| 8 | HDA | Hong Kong Dragon Airlines Limited t/a Dragonair | IATA: KA, Callsign: Dragonair, IATA Prefix: 043, ICAO callsign changed to Dragon | HK | AVCODES |
| 9 | HDA | Hong Kong Dragon Airlines Limited t/a Dragonair | IATA: KA, Callsign: Dragon, IATA Prefix: 043, ICAO callsign changed from Dragonair. Name changed to Hong Kong Dragon Airlines Limited t/a Cathay Dragon. | HK | AVCODES |
| 10 | HDA | Dragonair (DAL) | Callsign: Dragonair, Name chanaged to Hong Kong Dragon Airlines - Dragonair | HK | AVCODES |
| 11 | HDA | Hong Kong Dragon Airlines Limited t/a Cathay Dragon | IATA: KA, Callsign: Dragon, IATA Prefix: 043, Founded on 24 May 1985. Commenced operations in July 1985. Ceased operations on 21 October 2020. ICAO callsign changed from Dragonair . Name changed from Hong Kong Dragon Airlines Limited t/a Dragonair. | HK | AVCODES |
| 12 | HDA | Dragonair, Hong Kong Dragon Airlines | IATA: KA | | ICAO1 |
| 13 | HDA | Dragonair | | HK | TRAFFIC |
| 14 | HDAE | HEIFETZ, DAVID | | | SCAC4 |
| 15 | HDAI | HERNANDEZ DIAZ, ANTONIO MARTIN G | | | SCAC4 |
| 16 | HDAV | H A D D TRUCKING LLC | | | SCAC4 |
| 17 | HDBA | HALF DIAMOND EXPRESS LTD | | | SCAC4 |
| 18 | HDBB | HILL DE BAJA CALIFORNIA | | | SCAC4 |
| 19 | HDBE | HILDEBRAND, JIM | | | SCAC4 |
| 20 | HDBG | HYDER, B & A TRUCKING CO INC | | | SCAC4 |
| 21 | HDBQ | HYDE DRIFT BOATS INCORPORATED | | | SCAC4 |
| 22 | HDBS | HOUND DOG BUS | | | SCAC4 |
| 23 | HDBX | Blery Oil Co. | 8/1920 | | NAKINA |
| 24 | HDBX | BLERY OIL CO. | | | PWRC |
| 25 | HDC | Helicopteros de Cataluna, S.A. | Callsign: Helicataluna, | E | AVCODES |
| 26 | HDC | Helcopteros De Cataluna | | | ICAO1 |
| 27 | HDCM | HURTADO CRUZ, MIGUEL | | | SCAC4 |
| 28 | HDCN | HUDD TRANSPORTATION | | | SCAC4 |
| 29 | HDCO | H DANTAS COMERCIO NAVEGACAO E INDUS | | | SCAC4 |
| 30 | HDCR | HILLSDALE COUNTY RAILWAY | | | PWRC |
| 31 | HDCR | HAPPY D CORPORATION | | | SCAC4 |
| 32 | HDCW | HOLMAN DISTRIBUTION CENTER OF WASHINGTON, INC | | | SCAC1 |
| 33 | HDCW | HOLMAN TRANSPORTATION LLC | | | SCAC4 |
| 34 | HDCX | The Hull Corp. | 1/1994 (not listed) | | NAKINA |
| 35 | HDCX | The Hull Corp. | Jan-94 | | NRHS |
| 36 | HDCX | THE HULL CORPORATION | | | PWRC |
| 37 | HDDA | HERNDON, D A INC | | | SCAC4 |
| 38 | HDDC | HENRY, DAN DISTRIBUTING CO | | | SCAC4 |
| 39 | HDDD | HADDAD APPAREL GROUP LTD | | | SCAC4 |
| 40 | HDDE | HENRIE, DANIEL DENIS | | | SCAC4 |
| 41 | HDDH | HADDON HOUSE FOOD PRODUCTS INC | | | SCAC4 |
| 42 | HDDR | HUDD TRANSPORTATION | | | SCAC4 |
| 43 | HDDS | HAMMER DOWN DELIVERY SERVICES INC | | | SCAC4 |
| 44 | HDDW | HOOD, DAVID W TRUCKING INC | | | SCAC4 |
| 45 | HDDY | HIRD, DWAYNE | | | SCAC4 |
| 46 | HDE | HDE, INC. | | | PWRC |
| 47 | HDEE | HARD DRIVE EXPRESS INC | | | SCAC4 |
| 48 | HDEK | HARTMAN, D E TRUCKING INC | | | SCAC4 |
| 49 | HDEN | HARP, DARRELL ENTERPRISES INC | | | SCAC4 |
| 50 | HDEO | HOLDER, R D OIL CO INC | | | SCAC4 |
| 51 | HDER | HARDERS TRUCKING LTD | | | SCAC4 |
| 52 | HDES | HERRERA DESIGN | | | SCAC4 |
| 53 | HDFC | HOWARD FARMS INC | | | SCAC4 |
| 54 | HDFI | HAMMONDS, D F INC | | | SCAC4 |
| 55 | HDFL | HIGH DEFINITION LOGISTICS LLC | | | SCAC4 |
| 56 | HDFN | HI-DON FARMS INC | | | SCAC4 |
| 57 | HDFS | HIDDEN SPRING FARM/FAIRCLOUGH GAS I | | | SCAC4 |
| 58 | HDFU | HUADONG FERRY CO LTD | | ROK | BIC |
| 59 | HDFU | HUADONG SHIPPING CORPORATION | | | SCAC4 |
| 60 | HDFW | HOOD TRANSPORTATION (TRUCKLOAD DIVI | | | SCAC4 |
| 61 | HDGF | HEDIGERS FUEL OIL | | | SCAC4 |
| 62 | HDGH | HOME DELIVERY GROUP LLC, THE | | | SCAC4 |
| 63 | HDGJ | HORN, DAVE G | | | SCAC4 |
| 64 | HDGL | HYUNDAI GLOVIS CO LTD | | | SCAC4 |
| 65 | HDGM | HODGES OIL CO INC | | | SCAC4 |
| 66 | HDGR | HODGE, ROBERT TRUCKING LLC | | | SCAC4 |
| 67 | HDGU | HYUNDAI GLOVIS | | ROK | BIC |
| 68 | HDGX | Henry D. Gee | 7/1935-4/1938 | | NAKINA |
| 69 | HDGX | Henry D. Gee | Apr-38 | | NRHS |
| 70 | HDGX | H.D. GEE | | | PWRC |
| 71 | HDHA | HAMMER DOWN HAULIN INC | | | SCAC4 |
| 72 | HDHS | HAMMER DOWN HOT SHOT & PILOT (DIV O | | | SCAC4 |
| 73 | HDHU | FOSHAN MEIZONG HOUSING TECHNOLOGY CO., LTD. | | PRC | BIC |
| 74 | HDI | Hoteles Dinamicos, S.A. de C.V. | Callsign: Dinamicos, | MEX | AVCODES |
| 75 | HDI | Hoteles Dinamicos | | | ICAO1 |
| 76 | HDIB | HORIZON DRILLING INC | | | SCAC4 |
| 77 | HDII | HARD DRIVER INC | | | SCAC4 |
| 78 | HDIK | HENDRIKS, ANDREW & SONS GREENHOUSES | | | SCAC4 |
| 79 | HDIR | HEP DIRECT INC | | | SCAC4 |
| 80 | HDIS | HAROLD DISTRIBUTION INC | | | SCAC4 |
| 81 | HDIU | MCM INDUSTRIAL B.V. | | NL | BIC |
| 82 | HDIV | HEROUX DEVTEK INC | | | SCAC4 |
| 83 | HDIW | HORIZON GEMI ISLETMECILIGI SANAYI V | | | SCAC4 |
| 84 | HDJI | HARLOW, D J TRUCKING INC | | | SCAC4 |
| 85 | HDJK | HAMMONDS, J A TRUCKING INC | | | SCAC4 |
| 86 | HDJO | HERNANDEZ DAVILA, JESUS ALEJANDRO | | | SCAC4 |
| 87 | HDJT | HOWARD, J T S INC | | | SCAC4 |
| 88 | HDKE | HANDLEY, KEVIN E TRUCKING | | | SCAC4 |
| 89 | HDKG | HOOD TRUCKING | | | SCAC4 |
| 90 | HDKH | HELDT TRUCKING LLC | | | SCAC4 |
| 91 | HDKI | HENDRIK ENTING | | | SCAC4 |
| 92 | HDKJ | HEIDEL TRUCKING | | | SCAC4 |
| 93 | HDKK | HYUN DAE TRUCKING CO INC | | | SCAC4 |
| 94 | HDKL | HYDRATREK LLC | | | SCAC4 |
| 95 | HDKM | HUVALS, DAVID TRUCKING COMPANY INC | | | SCAC4 |
| 96 | HDKN | HOUDEK ENTERPRISES INC | | | SCAC4 |
| 97 | HDKQ | HEADRACK INC | | | SCAC4 |
| 98 | HDKR | HANDRICK TRUCKING LLC | | | SCAC4 |
| 99 | HDKW | HISAR DENIZCILIK TICARET VE SANAYI | | | SCAC4 |
| 100 | HDL | Hendell Aviation Oy | Callsign: Hendell, | FIN | AVCODES |
