ETT may refer to:
- Kaspar Ett a German composer and organist
- Effect of the treatment on the treated (ETT or TOT) in an Observational study
- Elementary Teachers of Toronto, a local of the Elementary Teachers' Federation of Ontario (ETFO) union.
- Embedded Training Team, a team of U.S. soldiers or Marines embedded with the Afghan National Army to help train its soldiers
- Endotracheal tube
- English Touring Theatre
- English Toy Terrier, a small breed of terrier in the toy dog group.
- Ergothioneine transporter (human gene symbol SLC22A4)
- Etruscan language (redirect from ISO 639:ett)
- European Transactions on Telecommunications Journal
- Exercise tolerance testing (also known as cardiac stress testing)
- Ek Tha Tiger, a 2012 Hindi action thriller film starring Salman Khan and Katrina Kaif.
- Effective Throat Thickness, a measure of effective weld thickness
abbr. endotracheal tube