| HAC | High Availability Clusters |
| HAI | Healthcare-Associated Infections |
| HAZOP | Hazard And Operability Analysis |
| HBF | Fetal Hemoglobin |
| HBO | Home Box Office |
| HBS | Hepatitis B Surface Antigen |
| HCC | Hepatocellular Carcinoma |
| HCI | Human-Computer Interaction |
| HCM | Human Capital Management |
| HDFS | Apache Hadoop Distributed File System |
| HFBC | High Frequency Broadcasting Conference |
| HHS | U.S. Department Of Health & Human Services |
| HLCL | Hindustan Computers Limited |
| HLS | Http Live Streaming |
| HMI | Human-Machine Interface |
| HMS | Her Majesty'S Ship |
| HOA | Homeowner Association |
| HOKA | Hands On Keyboard Access |
| HOLY | High On Loving You |
| HPI | History Of Present Illness |
| HPLC | High Performance Liquid Chromatography |
| HRBC | Hooghly River Bridge Commissioners |
| HRT | Hormone Replacement Therapy |
| HSM | Hardware Security Module |
| HTH | Hope This Helps |
| HULU | |
| HUMBLE | |
| HUMILITY | |
| HVAC | Heating, Ventilation, And Air Conditioning |