IES

The initialism IES may refer to:

Government organizations

 * Indian Economic Service
 * Indian Education Service, in British India
 * Institute for Environment and Sustainability of the European Commission
 * Institute of Education Sciences of the U.S. Department of Education

Non-profit organizations

 * Institute for the International Education of Students
 * Illuminating Engineering Society
 * International Enterprise Singapore
 * International Society of Endocrinology
 * Israel Endocrine Society
 * Israel Exploration Society
 * Institution of Environmental Sciences

Companies

 * IES Ltd (Integrated Export Systems), a transportation software company
 * Integrated Electrical Services
 * Internationella Engelska Skolan

Other

 * Indian Engineering Services
 * Integrated Encryption Scheme, in cryptography, a public key cryptosystem
 * Intertemporal elasticity of substitution
 * Intuitive eating scale
 * The Indrema Entertainment System, also known as the L600, an unreleased sixth generation video game console