DTT may refer to:
- Deutscher Terminologie-Tag, German Terminology Association, known by its German initials
- Double taxation treaty, a type of international agreement to mitigate the effects of double taxation on multinational businesses
- Digital terrestrial television
- Discrete trial training
- Deloitte Touche Tohmatsu or DTT International, financial services firm
- Dithiothreitol or Cleland's reagent in chemistry
- The IATA airport code for the Detroit metropolitan area