| IECS | Igloo Environment Control Subsystem 
| Others |
| IECS | Inland Empire Commuter Services
| Others |
| IECS | Innovation in an Era of Challenging Sites
| Others |
| IECS | Institute for Education Community and Society
| Others |
| IECS | Institute of Engineering and Computing sciences
| Others |
| IECS | Institute of Environmental Change and Society
| Others |
| IECS | Institute of Estuarine and Coastal Studies
| Others |
| IECS | Instituto de Efectividad Clinica y Sanitaria
| Others |
| IECS | Instituto Europeo Campus Stellae
| Others |
| IECS | Integrated E Community System
| Others |
| IECS | Integrated Electromagnetics Circuits and Systems
| Others |
| IECS | Integrated Emergency Command Structure
| Others |
| IECS | Integrated Environment for Communication on Ship
| Others |
| IECS | Integrated Environmental Control System
| Others |
| IECS | Intelligent Electronic Control Suspension
| Others |
| IECS | Intelligent Energy Control System
| Others |
| IECS | Intelligent Enterprise Control System
| Others |
| IECS | Intentionally Evangelistic Church Strategy
| Others |
| IECS | International Economic Conference of Sibiu
| Others |
| IECS | International Education Consultancy Services
| Others |
| IECS | International Education Consultants and Supplies
| Others |
| IECS | International English and Cultural Studies
| Others |
| IECS | International Erosion Control Systems
| Others |
| IECS | International Export Certification Services
| Others |
| IECS | Inventory of Existing Chemical Substances
| Others |
| IECS | Irish Ethical Celebrants Society
| Others |
| IECS | Islamic Educational Center of Seattle
| Others |