IAS

IAS may stand for:

 Accounting, Auditing 
International Accounting Standards
Internal Audit Service (European Commission)

 Administration 
Indian Administrative Service (Civil Service)

 Religion 
International Association of Scientologists

 Science 
Institute for Advanced Study
IAS computer, built at the Institute for Advanced Study
Institut d'Astrophysique Spatiale
Indian Academy of Sciences
Islamic World Academy of Sciences, an organization promoting science and technology in the Muslim World
Iranian Arachnological Society, an academic society for Iranian and International arachnologists

 Health 
International AIDS Society, the world's leading independent association of HIV/AIDS professionals

 Politics 
Institute for Anarchist Studies

 Technology 
 Aeronautics 
Indicated airspeed
Institute of the Aeronautical Sciences
Institut aéronautique et spatial

 Computing 
Internet Authentication Service
Internet Application Server, a component of Oracle Application Server from Oracle Corporation
IAS, a version of Digital Equipment Corporation's RSX-11 operating system

 Transportation 
Iaşi International Airport in Iaşi, Romania, designated by IATA the airport code IAS
IAS Cargo Airlines, a British airline

 Other 
Independent Australian Scouts
Instituto Ayrton Senna