| Acronym | Definition |
|---|
| IACS | International Association of Classification Societies |
| IACS | Indian Association for the Cultivation of Science |
| IACS | Integrated Administration and Control System (EU system to administer payments under the common agricultural policy) |
| IACS | Instituto de Arte e Comunicação Social (Portuguese: Institute for Art and Media; Brazil) |
| IACS | Illinois Association of Convenience Stores |
| IACS | Industrial Automation and Control Systems |
| IACS | International Academy of Cardiovascular Sciences (Minnetonka, MN) |
| IACS | Installation Access Control System |
| IACS | International Association of Counseling Services, Inc. (Alexandria, VA) |
| IACS | International Association of Chemical Societies |
| IACS | Integrated Avionics Control System |
| IACS | Integrated Armament Control System |
| IACS | Integrated Acoustic Communications System |
| IACS | International Annealed Copper Standard for conductivity |
| IACS | Illinois Association of Christian Schools |
| IACS | Insurance Accounting Collection System (US HUD) |
| IACS | Iranian-American Cultural Society of Maryland, Inc. |
| IACS | Information, Assurance & Certification Services (CESG, UK) |
| IACS | Informatique Avancée Communication et Services (French) |
| IACS | Intelligence Acoustic Communication System (US DoD) |
| IACS | Individuals Access to CMS (Centers for Medicare and Medicaid Services) Systems (US DHHS) |
| IACS | I Am Charlotte Simmons (Tom Wolfe book) |