| Acronym | Definition |
|---|
| HDO➣High Definition Optics (various companies) |
| HDO➣Health Delivery Organization (various organizations) |
| HDO➣High Density Overlay (phenolic resin-impregnated plywood used in concrete forms) |
| HDO➣Human Development Organization (Sri Lanka) |
| HDO➣Holy Day of Obligation |
| HDO➣Hearing Designation Order (FCC proceedings) |
| HDO➣Healthcare Discount Organization (Addvantage Care) |
| HDO➣Heavy Duty Oil |
| HDO➣High Demand Occupation |
| HDO➣Humanitarian Demining Operation |
| HDO➣Hydrogen Deuterium Oxide |
| HDO➣Headache During Orgasm |
| HDO➣Homeland Defense Office |
| HDO➣Housing Development Office |