IAS

IAS may refer to:

Science

 * Institute for Advanced Study, in Princeton, New Jersey, United States
 * Image Analysis & Stereology, the official journal of the International Society for Stereology & Image Analysis.
 * Iowa Archeological Society, United States
 * Iranian Arachnological Society, for the study of arachnids in Iran
 * International AIDS Society, an association of HIV/AIDS professionals
 * Institute of Agricultural Sciences, Banaras Hindu University, in India
 * Institute for Advanced Study at University of Minnesota in Minneapolis, Minnesota
 * Institute of Advanced Study (Durham) in Durham, North East England
 * IEEE Industry Applications Society

Government

 * Indian Administrative Service, the Indian administrative civil service
 * Intergovernmental Affairs Secretariat (Canada)

Finance

 * International Accounting Standards
 * Internal Audit Service (European Commission)
 * Investment Analysts Society of Southern Africa
 * various numbered International Financial Reporting Standards

Religion

 * International Association of Scientologists
 * International Association of Sufism

Politics

 * Institute for Anarchist Studies
 * Izquierda Asturiana, a political party in Spain
 * Immunisation Awareness Society, a New Zealand anti-vaccination group
 * International Aviation and Shipping emissions, specifically greenhouse gas emissions arising from those sectors (the term also used in the United Kingdom Climate Change Act 2008)

Aeronautics

 * Indicated airspeed
 * Institute of Aerospace Sciences, in the United States
 * Institut aéronautique et spatial, in France
 * Iași International Airport, IATA designation for the airport in Iași, Romania
 * IAS Cargo Airlines, a British airline

Computing

 * IAS machine, the first electronic computer built at the Institute for Advanced Study
 * Interactive Application System, a DEC PDP-11 operating system
 * Internet Application Server, alternate name for Oracle Application Server
 * Internet Authentication Service, a component of Windows Server

Other uses

 * Instituto Ayrton Senna, an NGO in Brasil
 * Insulin autoimmune syndrome, a rare cause of reversible autoimmune hypoglycemia
 * Integral Ad Science, an American technology company that analyzes the value of digital advertisements
 * International American School of Warsaw, a preK–12 school in Poland
 * International Automated Systems, an American company
 * IAS Limited an Australian-based gambling company
 * Internal anal sphincter, human anatomy