ETT

Ett or ETT may refer to:

Arts

 * Caspar Ett (1788–1847), German composer and organist
 * English Touring Theatre

Mathematics

 * Euler tour technique, in graph theory
 * Extensional type theory, in logic

Medicine

 * Endotracheal tube, in respiratory medicine
 * Epithelioid trophoblastic tumour, a very rare cancer
 * Ergothioneine transporter, a protein and human gene (SLC22A4)
 * Exercise Tolerance Test, in cardiology

Military

 * Embedded Training Teams in Afghanistan
 * EBR ETT, a French armoured personnel carrier

Other uses

 * Elementary Teachers of Toronto, a Canadian labour union
 * English Toy Terrier, a dog breed
 * Etruscan language, once spoken in Italy (ISO 639-3: ett)
 * European Transactions on Telecommunications, a scientific journal
 * Evacuated Tube Transport