| Acronym | Definition |
|---|
| HSA | Health Savings Account (US) |
| HSA | Health Sciences Authority (Singapore) |
| HSA | Human Serum Albumin |
| HSA | Home School Association |
| HSA | Health and Safety Authority (Ireland) |
| HSA | High School Assessment |
| HSA | Home and School Association |
| HSA | Health Services Agency |
| HSA | Human Services Agency (Nevada) |
| HSA | Homeland Security Act |
| HSA | Health Service Area |
| HSA | Hemispheric Social Alliance |
| HSA | Haiku Society of America |
| HSA | Harmony Science Academy (Texas) |
| HSA | Hunt Saboteurs Association |
| HSA | High Speed Access (CATV) |
| HSA | Herb Society of America |
| HSA | Health Sciences Association |
| HSA | Housing Studies Association |
| HSA | Head Stack Assembly (hard disk drives) |
| HSA | Harlem School of the Arts (New York, NY) |
| HSA | Health Systems Agency |
| HSA | Hollow-Stem Auger |
| HSA | High Speed Amphibian |
| HSA | Homeland Security Agency |
| HSA | Hispanic Student Association |
| HSA | Honors Student Association |
| HSA | Handicapped Scuba Association International |
| HSA | Health Science Authority (Singapore) |
| HSA | High Specific Activity |
| HSA | Home Sewing Association |
| HSA | Hot Sedimentary Aquifer |
| HSA | Hellenic Students' Association |
| HSA | Home Savings of America |
| HSA | Health Service Agreement |
| HSA | Hip Structural Analysis |
| HSA | Hmong Student Association (various universities) |
| HSA | Hexane-Sulfonic Acid |
| HSA | History Students Association |
| HSA | Health Scientist Administrator |
| HSA | Hydrologic Sub-Area |
| HSA | Hazardous Substances Act |
| HSA | Hindu Students Association |
| HSA | Hydrographic Sciences Australia |
| HSA | High System Availability (Cisco) |
| HSA | Hot Side Aeration |
| HSA | Holmes Safety Association |
| HSA | Hoffman Sports Association |
| HSA | High-Speed Analog |
| HSA | Horizon Science Academy |
| HSA | Heartland Spiritual Alliance |
| HSA | Healing Story Alliance |
| HSA | Hammons School of Architecture (Drury University) |
| HSA | Home Service Area |
| HSA | Hazardous Substances Authority (UK) |
| HSA | Healthcare Supplies Association |
| HSA | Headache Associated with Sexual Activity |
| HSA | Hilbert Spectral Analysis (Hilbert-Huang transform) |
| HSA | Hunter's Shooting Association |
| HSA | Homeschoolers' Support Association |
| HSA | Hueston Sailing Association |
| HSA | Handbell Society Of Australasia |
| HSA | Home Show America |
| HSA | Hawaii Skatepark Association |
| HSA | Hydroponics Society of America |
| HSA | Huguenot Society of America |
| HSA | Hand Surgical Associates |
| HSA | Hi Specialty America |
| HSA | Hudson Society of Artists (Hudson, OH, USA) |
| HSA | Humane Slaughter Act of 1958 |
| HSA | Honors Scholars Association |
| HSA | Health and Safety Assurance |
| HSA | Hinchingbrooke School Association |
| HSA | Health Services Administrator/Administration (USAF) |
| HSA | Heaven's Sword Army (gaming community) |
| HSA | Hach Scanning Analyzer |
| HSA | Hazardous Substance Analysis |
| HSA | Hot Solo Action |
| HSA | High Speed Auxiliary |
| HSA | Harmonic Suppressed Antenna |
| HSA | Harrison Smith Associates Limited |
| HSA | Higher Studies Abroad |
| HSA | High Source Alignment |
| HSA | Has Sex Appeal (chat slang) |
| HSA | Hydroxy Steatic Acid |
| HSA | Human Serum Albumin Radical |
| HSA | Hot Spot Analysis (environmental study) |
| HSA | Health Services Academy (various locations) |
| HSA | Hermalle-Sous-Argenteau (Belgium seaport) |
| HSA | Health Services Administration (various locations) |