| Acronym | Definition |
|---|
| HCO➣Html Converter |
| HCO➣Harvard College Observatory |
| HCO➣Hearing Carry-Over |
| HCO➣Hubbard Communications Office (Scientology) |
| HCO➣Health Care Organization |
| HCO➣Hydraulic Clearance Optimization (gas turbine technology; Siemens) |
| HCO➣Health Care Ombudsman (Vermont) |
| HCO➣Honor Code Office (Brigham Young University; Utah) |
| HCO➣Heavy Cycle Oil |
| HCO➣Human Capital Office (various companies and government agencies) |
| HCO➣Hollister Company (clothing line) |
| HCO➣Human Capital Officer |
| HCO➣Helicopter Control Officer |
| HCO➣Hierarchical Cycloid Overlay (algorithms) |
| HCO➣Head of Contracting Office |
| HCO➣Health Care Officer |
| HCO➣Heights Chamber Orchestra (Cleveland Heights, OH) |
| HCO➣HC Orsteds Institute (Copenhagen, Denmark) |