IAA

IAA may refer to:

Science and medicine

Terminology

• Imidazole-4-acetic acid, a neurotransmitter metabolite
• Indole-3-acetic acid, a plant hormone
• Aux/IAA repressors, a class of early auxin responsive transcription factors in plants
• Inflammatory aortic aneurysm, a medical condition
• Insulin autoantibody, used in diagnosing Latent autoimmune diabetes
• Interrupted aortic arch, a medical condition
• Iodoacetamide, an alkylating agent
• Isoamyl alcohol, a common name for 3-Methylbutan-1-ol

Institutions & associations

• Academia Sinica Institute of Astronomy and Astrophysics, a research institute in Taiwan
• Instituto Antártico Argentino, Argentine Antarctic Institute: federal agency for Antarctic research
• Instituto de Arqueología Amazónica, archeological research institute in Peru
• Instituto de Astrofísica de Andalucía (IAA-CSIC), research institute in Spain
• International Academy of Architecture, Bulgarian NGO & NPO
• International Academy of Astronautics, Swedish NGO
• International Actuarial Association, worldwide association of actuarial associations
• International Astrostatistics Association
• Israel Antiquities Authority, Israeli governmental authority
• Israeli Astronomical Association

Aviation

• Igarka Airport IATA code
• Indianapolis Airport Authority
• Iran Aseman Airlines, an Iranian airline
• Irish Aviation Authority
• Israel Airports Authority
• International Academy of Astronautics

Automobile

• International Motor Show Germany, known natively as Internationale Automobil-Ausstellung

Computing

• Interactive Achievement Awards, now known as D.I.C.E. Awards

Education

• Idyllwild Arts Academy, a private high school in Idyllwild, California
• Intercollegiate Athletic Association, former name of the National Collegiate Athletic Association
• Interlochen Arts Academy, a boarding school at the Interlochen Center for the Arts
• Inter-American Academy of Guayaquil, an international school in Ecuador

Politics

• Information Affairs Authority of Bahrain

Sports

• International Ammunition Association

Associations (non-science-related)

• Illinois Agricultural Association
• Immigration Appellate Authority (UK)
• Independent Ambulance Association representing private ambulance services in the UK
• Indian Association of Alberta
• Institute for Applied Autonomy
• International Advertising Association, international marketing industry association
• International Association of Art
• Investment Adviser Association

Other uses

• Id al Adha, Muslim holiday
• Intelligence Authorization Act (1991 - U.S.)
• Islamic Army of Aden, militant group designated as a terrorist organization by Bahrain, Canada and the UK
• International Affairs Agency, parody of the Central Intelligence Agency in Grand Theft Auto V