ETR

ETR may refer to:

Transportation

 * ElettroTreno, a series of Italian high-speed trains
 * Echigo Tokimeki Railway, a railway operating company in Japan
 * Santa Rosa International Airport, serving Machala, Ecuador
 * Essex Terminal Railway, a short line railroad in Canada

Other

 * Second East Turkestan Republic
 * Express Toll Route, in Canada; Ontario Highway 407
 * Entergy Corporation; NYSE stock symbol
 * Edolo language; ISO language code
 * Etravirine, a drug used to suppress HIV replication
 * Existential theory of the reals, formal language in computer science