| Acronym | Definition |
|---|
| HPA | Health Protection Agency (UK) |
| hPa | Hectopascal |
| HPA | Hawaii Preparatory Academy |
| HPA | Host Protected Area (hard disks) |
| HPA | High Power Amplifier |
| HPA | Illinois Historic Preservation Agency |
| HPA | Historic Preservation Agency |
| HPA | Health Plan Administrator |
| HPA | High Pressure Air |
| HPA | Hydraulic Project Approval |
| HPA | High Performance Analog |
| HPA | Health Policy and Administration (education program) |
| HPA | Hazardous Products Act |
| HPA | Home Price Appreciation |
| HPA | High Performance Addressing |
| HPA | Human Platelet Antigen |
| HPA | HomePlug Powerline Alliance |
| HPA | Human-Powered Aircraft |
| HPA | Haunted Pennsylvania (website) |
| HPA | Hanoi Plan of Action |
| HPA | Hamilton Port Authority (Canada) |
| HPA | Hawaii Psychological Association |
| HPA | Hermes Precisa Australia |
| HPA | Health Policy Authority |
| HPA | Hard Physical Address |
| HPA | Hydraulic Power Assist (Ford) |
| HPA | Higher-order Path Adaptation |
| HPA | High Point Academy (middle school in Pasadena, California) |
| HPA | Hyperphenylalaninemia, Mild |
| HPA | Horse Protection Act of 1970 |
| HPA | Hydroxy-Propyl Acrylate |
| HPA | Homeowner's Protection Act of 1998 |
| HPA | Hypophyseal-Pituitary Axis |
| HPA | Histoplasma Capsulatum Polysaccharide Antigen |
| HPA | Horizontal Planar Array |
| HPA | Home Page Award |
| HPA | Higher Polyamine (chemical) |
| HPA | Head of Procuring Activity |
| HPA | Hereditary Papulotranslucent Acrokeratoderma |
| HPA | Half-Power Angle |
| HPA | Head of Processing Activity |
| HPA | Hydraulic Power Assembly |
| HPA | Hypothalamic-Pituitary-Adrenal/Adrenocortical |