IAS stands for:

• Indicated Airspeed
• Ideal Adsorbed Solution - thermodynamic theory of adsorption of Minka and Myers
• International Accounting Standards
• International Adsorption Society
• Institute for Advanced Study
• Institute for Anarchist Studies
  • The IAS computer built at the Institute for Advanced Study
• Institute of the Aeronautical Sciences
• International Association of Scientologists
• Indian Administrative Service
• Internet Authentication Service