IAA

IAA may refer to:

• International Academy of Architecture
• International Academy of Astronautics
• International Actuarial Association
• International Advertising Association
• International Ammunition Association
• International Astrostatistics Association

• Idyllwild Arts Academy, in Idyllwild, California, US
• Interlochen Arts Academy of the Interlochen Arts Academy, in Miichigan, US
• Inter-American Academy of Guayaquil, in Ecuador
• International Academy Amman, a school in Jordan

• Indianapolis Airport Authority, in the US
• Irish Aviation Authority
• Israel Airports Authority

• Academia Sinica Institute of Astronomy and Astrophysics, in Taiwan
• Illinois Agricultural Association, now Illinois Farm Bureau, in the US
• Immigration Appellate Authority, in the UK
• Independent Ambulance Association, in England
• Indian Association of Alberta, in Canada
• Institute for Applied Autonomy, an activist group of anonymous artists
• Information Affairs Authority, in Bahrain
• Instituto Antártico Argentino ('Argentine Antarctic Institute')
• Instituto de Arqueología Amazónica ('Amazon Archaeology Institute'), in Peru
• Instituto de Astrofísica de Andalucía ('Institute of Astrophysics of Andalusia')
• Israel Antiquities Authority
• Israeli Astronomical Association

• Imidazoleacetic acid, a neurotransmitter metabolite
• Indole-3-acetic acid, a plant hormone
• Inflammatory aortic aneurysm, a medical condition
• Interrupted aortic arch, a heart defect
• Iodoacetamide, an alkylating agent for peptide mapping
• Isoamyl alcohol, a common name for 3-Methylbutan-1-ol

• Igarka Airport, Russia, IATA code IAA
• Iran Aseman Airlines, an Iranian airline

• Interactive Achievement Awards, now D.I.C.E. Awards, in the video game industry
• International Affairs Agency, a fictional entity in Grand Theft Auto V
• International Motor Show Germany, or Internationale Automobil-Ausstellung
• Islamic Army of Aden, or Aden-Abyan Islamic Army, a Sunni Islamist militant group in Yemen