ECN may refer to:
Organizations and companies
- ECN (TV station), former name of NEN, in New South Wales, Australia
- ECN Capital, a Canadian financing company
- Electoral Commission of Namibia
- Energy Research Centre of the Netherlands (Dutch: ')
- Environmental Change Network, of the British Natural Environment Research Council
- Ercan International Airport, in Northern Cyprus
- European Competition Network
- European Crowdfunding Network
Science and technology
- Electrochemical noise, fluctuations of current and potential
Computing
- Electronic communication network, for trading of financial products
- Explicit Congestion Notification, in network congestion
- Encoding Control Notation, a formal language that is part of the Abstract Syntax Notation One
- Ethernet Consist Network, protocol used in train communications
Other uses
- Engineering change notice, used to implement changes to components or products
- Enhanced capital note, a fixed-income instrument
- Eastman Color Negative, a photographic processing system