| Acronym | Definition |
|---|
| AHA | American Heart Association |
| AHA | American Hospital Association |
| AHA | Australian Healthcare Association |
| AHA | American Homeschool Association |
| AHA | Activity Hazard Analysis |
| AHA | American Hypnosis Association |
| AHA | Area Hazard Analysis |
| AHA | Air Alpha Greenland (ICAO code) |
| AHA | Anger Hostility Aggression |
| AHA | American Hardwood Association |
| AHA | Arrived Holding Area |
| AHA | American Helicopter Association |
| AHA | Animal Health Auxiliary |
| AHA | Albert Hydeman Associates |
| AHA | Alberta Handgun Association |
| AHA | Analog Headend Assembly |
| AHA | Assembly Hazard Analysis |
| AHA | Automated Historical Archives |
| AHA | Alexander Hancock Associates (Davidson, NC) |
| AHA | Algorithmes Hybrides et Adaptatifs (French: Adaptive and Hybrid Algorithms) |
| AHA | Assessment of Human Agency (Penn State University) |
| AHA | Acetohydroxamic Acid (chemistry) |
| AHA | Athletes Helping Athletes (various locations) |
| AHA | American Hardboard Association (Palatine, Illinois) |
| AHA | Australian Hotels Association (Australia; est. 1839) |
| AHA | Artists Helping Artists |
| AHA | American Humane Association |
| AHA | Arabian Horse Association (Aurora, Colorado) |
| AHA | African Humanitarian Action |
| AHA | Admins Helping Admins (gaming leagues) |
| AHA | After Hours Activities (various organizations) |
| AHA | Ancient History and Archaeology (various locations) |
| AHA | American Homeowners Association |
| AHA | Airport Handling Agents |
| AHA | American Humanist Association |
| AHA | At Home America (home decorating accessories) |
| AHA | Advocates for Health in Action (North Carolina) |
| AHA | Animal Health Act (UK) |
| AHA | Antihyperglycemic Agent |
| AHA | Anesthesia History Association |
| AHA | Alert Holding Area (Army definition) |
| AHA | Academy of the Holy Angels |
| AHA | American Health Association |
| AHA | American Hereford Association |
| AHA | American Hippotherapy Association |
| AHA | American Historical Association |
| AHA | American Homebrewers Association |
| AHA | Alpha Hydroxy Acid |
| AHA | American Hyperlexia Association |
| AHA | Ammunition Holding Area |