ETS
ETS or ets may refer to:

Climate change, environment and economy
Emissions trading scheme
European Union Emission Trading Scheme

Organisations
European Thermoelectric Society
Evangelical Theological Society

Education
École de technologie supérieure, an engineering school in Montreal, Canada
Educational Testing Service, an American assessment organization
Educational and Training Services Branch, of the British Army
European Theological Seminary, in Kniebis, Germany

Science and technology
Endoscopic thoracic sympathectomy
Enhanced Transmission Selection
Enterprise test software
Enterprise Transport Security, in computer security
Environmental tobacco smoke
Episodic tremor and slip
ETS transcription factor family
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Transport
East Tsim Sha Tsui station, of the  Mass Transit Railway, Hong Kong
Edmonton Transit Service, Alberta, Canada
Electric train supply, which powers auxiliary systems on rail vehicles
Enterprise Municipal Airport (Alabama)
Eureka Transit Service, California, US
Euskal Trenbide Sarea, a railway infrastructure company in the Basque Country, Spain
KTM ETS, a high-speed train service in Malaysia

Other uses
Afenmai language (ISO 639-3 code)
European Training Strategy, of the European Commission
Marie Hall Ets (1895–1984), American writer and illustrator
Expiration of Term of Service, in US military separation