ECS
- Amiga Enhanced Chip Set
- EDNS Client Subnet
- East Coast Swing
- Eccles Road railway station
- Ecuadorian Sign Language
- Ecuadorian sucre
- Edinburgh Concurrent Supercomputer
- Education Commission of the States
- Electrochemical Society
- Elitegroup Computer Systems
- Embodied cognitive science
- Emerald City Supporters
- Emergency communication system
- Empty coaching stock
- Endocannabinoid system
- Engleside Christian School
- Enterprise cognitive system
- Entity component system
- Environmental control system
- Equilibrium climate sensitivity
- Esports Championship Series
- Estuary Crossing Shuttle
- Etowah City Elementary School District
- European Calcium Society
- European Solidarity Centre
- Evangelical Christian School
- Evangelical Christian School (Fort Myers, Florida)
- Evansville Christian School
- Everett Christian School
- Media, Entertainment and Arts Alliance
- Metrovagonmash Ečs
- Miss Edgar's and Miss Cramp's School
- School of Education, Communication and Society
- School of Electronics and Computer Science, University of Southampton
- Écs