ECR can stand for
- Associations
- Efficient Consumer Response, a trade and industry body
- US Institute for Environmental Conflict Resolution
- European Conservatives and Reformists, a grouping within the European Union
- Radio
- East Coast Radio (South Africa), a South African radio station (FM 94-95)
- East Coast Radio (Ireland), an Irish radio station
- Transportation
- Roads:
- East Coast Road, a scenic beachway along the Coromandel coast of South India
- East Cross Route in London
- El Camino Real an old Spanish road in California
- Railways
- East Croydon station
- Euro Cargo Rail, rail freight operator based in France
- East Central Railway, part of the Indian rail network, see East Central Railway Zone (India)
- Eastern Counties Railway, defunct British railway company
- Science and technology
- Electron cyclotron resonance, a phenomenon in physics
- European Congress of Radiology
- Other
- Edmonton Capital Region
- Electronic Cash Register
- Engine control room (shipbuilding abbreviation)
- Early Career Researcher