TTD
- Piledriver (professional wrestling)
- Portland-Troutdale Airport
- Terence Trent D'Arby
- The Trade Desk
- Therapeutic Targets Database
- Tic-Tac-Dough
- Tirumala Tirupati Devasthanams
- Top Thrill Dragster
- Total Terminal Difficulty
- Transport Tycoon Deluxe
- Trichothiodystrophy
- Trinidad and Tobago dollar
- True time delay