| Acronym | Definition |
|---|
| ECN | Explicit Congestion Notification |
| ECN | Economics |
| ECN | Engineering Computer Network |
| ECN | Electronic Component News (electronics industry periodical) |
| ECN | Electronic Communications Network (stock market) |
| ECN | Energieonderzoek Centrum Nederland |
| ECN | Elite Casting Network (est. 1998) |
| ECN | Épreuves Classantes Nationales (French educational testing) |
| ECN | European Competition Network (EU) |
| ECN | Examen Classant National (French: National Review Ranking) |
| ECN | Environmental Change Network (UK) |
| ECN | Exhibit City News (convention industry) |
| ECN | Electronic Communications Network |
| ECN | Electronic Change Notification |
| ECN | Environmental Change Network |
| ECN | Engineering Change Notice |
| ECN | Electoral Commission of Namibia (Namibia) |
| ECN | Energy Research Center of the Netherlands (Petten, The Netherlands) |
| ECN | Ecole Centrale de Nantes (French College of Engineering) |
| ECN | European Counter Network |
| ECN | Engineering Change Notification |
| ECN | Emergency Communications Network (telephone emergency services) |
| ECN | Encoding Control Notation |
| ECN | Enhanced Capital Note |
| ECN | Electronic Commerce Network |
| ECN | Electronic Crossing Network |
| ECN | Extended Choice Network (enhancement of NHS Choose & Book system) |
| ECN | Educational Computing Network |
| ECN | Environmental Capital Network |
| ECN | Early Childhood Network |
| ECN | Epoxy Cresol Novolac |
| ECN | Equipment Control Number |
| ECN | Eastman Color Negative (film processing) |
| ECN | El Cajon National (sports; El Cajon, CA) |
| ECN | Electronic Change Notice |
| ECN | Enteral Clinical Nutrition |
| ECN | EcoNews Africa |
| ECN | Eventchannelnetwork (Object Oriented, Real-Time Asynchronous Communication Infrastructure for Embedded Systems) |
| ECN | Minimum Essential Emergency Communications Network (US DoD) |
| ECN | Electron Configuration Notation |
| ECN | Executive Consultants Network |
| ECN | Employment Change Notice |
| ECN | Executive Control Node (US FEMA) |
| ECN | Evolving Clustering Network |
| ECN | Lefkosa, Cyprus (Turkish Part) - Ercan Airport (Airport Code) |
| ECN | Equipage Category Number |