ETT may refer to:
- Endotracheal tube
- English Toy Terrier, a small breed of terrier in the toy dog group.
- Embedded Training Team, a team of U.S. soldiers or Marines embedded with the Afghan National Army to help train its soldiers
- Elementary Teachers of Toronto, a local of the Elementary Teachers' Federation of Ontario (ETFO) union.
- Effect of the treatment on the treated (ETT or TOT) in an Observational study
- Exercise tolerance testing (also known as cardiac stress testing)
- Ergothioneine transporter (human gene symbol SLC22A4)
- European Transactions on Telecommunications Journal
- Ek Tha Tiger, a 2012 Hindi action thriller film starring Salman Khan and Katrina Kaif.