| HDH | Hackwith Design House
| Others |
| HDH | Harper Dennis Hobbs
| Others |
| HDH | Hart Davis Hart
| Others |
| HDH | HDL Design House
| Others |
| HDH | HDLC Distant Host
| Others |
| HDH | Head Direct Hit
| Others |
| HDH | Health Data Hosting
| Others |
| HDH | Healthcare Development Holding
| Others |
| HDH | Heart Disease History
| Others |
| HDH | Highland District Hospital
| Others |
| HDH | Hoffe Das Hilft
| Others |
| HDH | Holland Dozier Holland
| Others |
| HDH | Holoprosencephaly diencephalic hamartoblastoma
| Others |
| HDH | Home Dear Home
| Others |
| HDH | Horse Drawn Horse
| Others |
| HDH | Housing Dining Hospitality
| Others |
| HDH | Houssiere Durant Houssiere
| Others |
| HDH | Hue Dark Histogram
| Others |
| HDH | Hundred Dollar Headshot
| Others |
| HDH | Huntington Disease Homolog
| Others |