| H/W | Hardware |
| H&S | health and safety |
| HA | hazard analysis |
| HA | High Accuracy |
| HA | High Availability |
| HAMMA | Huntsville Alabama Marx Meter Array |
| HAR | Hardware Acceptance Review |
| HASS | SXI High Accuracy Sun Sensor |
| HB | Heartbeat |
| HBA | Host Bus Adaptor |
| HBT | Hydrazine Bi-Propellant Thruster (SC KO) |
| HCI | Human Computer Interface |
| HCP | Harris Collaborative Portal |
| HDBK | Handbook |
| HDDL | Harris Development and Demonstration Lab |
| HDF | Hierarchical Data Format |
| HDP | Hardware Development Plan |
| HDT | Hardware Debug Tool |
| HDVIP | High Density Vertically Interconnected Photodiode |
| HEA | Headquarters Export Administrator (NASA) |
| HEC | Header Error Code |
| HEL | High Electron Laser |
| HELSTF | High Energy System Test Facility |
| HEPAD | EPS/High Energy Proton and Alpha Detector |
| HEPP | Human Engineering Program Plan |
| HES | Hyperspectral Environmental Suite |
| HFMS | High Fidelity Mechanical Simulator |
| HGA | High Gain Antenna |
| HIE | Hurricane Intensity Estimation |
| HIDP | Host-based Intrusion Detection and Prevention |
| HIDS | Host Intrusion and Detection Software |
| HIPS | Host-based Intrusion Prevention System |
| HIRDLS | High Resolution Dynamics Limb Sounder |
| HIRS | High Resolution Infrared Radiation Sounder (on NOAA TIROS-N series and MetOp satellites) |
| HITRAN | High Resolution Transmission |
| HITS | Harris IT Services |
| HK | Housekeeping |
| HMAC | Hash Message Authentication Code |
| HMD | Hardware Maintenance Depot |
| HMEA | Hazard Modes and Effects Analysis |
| HMI | Hit/Miss Index |
| HMI | Human Machine Interface |
| HMS | Hazard Mapping System (NOAA/NESDIS) |
| HMT | Hydrometeorology Testbed |
| HON | Honeywell International Corporation |
| HOPA | High Output Paraffin Actuator (GLM) |
| HOTTB | Hot Thermal Balance |
| HP | Heat Pipe |
| HP | Hewlett-Packard |
| hPa | hectopascals |
| HPA | High Performance Analog |
| HPA | High Power Amplifier |
| HPC | Hydrometeorological Prediction Center |
| HPOL | Horizontal Polarization |
| HQ | headquarters |
| HR | Hazard Report |
| HR | Hurricane Rated |
| HRC | High Resolution Coating |
| HRFS | High Reliability File System |
| HRG | Hemispherical Resonating Gyros |
| HRI | Hazard Risk Index |
| HRIT / EMWIN | High Rate Information Transmission/Emergency Managers Weather Information Network (formerly known as EMWIN/LRIT) |
| HRM | Heat Rejection Mirror |
| HRR | Handover Readiness Review |
| HRRR | High Resolution Rapid Refresh |
| HS | Hot Standby |
| HSFS | High Speed Frame Sync |
| HSIO | High Speed Input/Output |
| HSKP | Housekeeping |
| HSO | Hot Standby Operation |
| HSPD | Homeland Security Presidential Directive |
| HSS | Heidke Skill Score |
| HTEMS | HUB Tivoli Enterprise Management Server |
| HTL | Hazard Tracking Log |
| HTML | Hypertext Transfer Protocol |
| HTSI | Honeywell Technology Solutions Incorporated |
| HTTP | Hyper Text Transfer Protocol |
| HVAC | Heating, Ventilation, and Air Conditioning |
| HVEPC | High Voltage Electrical Power Converter |
| HW | Hardware |
| HWCI | hardware configuration item |
| HWIL | Hardware in the Loop |
| HWIT | Hardware Integration and Test |
| HWPS | Hardware Procurement Specification |
| HWRS | Hardware Requirements Specification |
| HWT | Hazardous Weather Testbed |
| HyDICE | Hyperspectral Digital Imagery Collection Experiment |
| Hz | Hertz |