| Abbreviation | Definition |
|---|---|
| TFTH | Thanks For The Hike |
| TFW | Tropical Fresh Water |
| TGIF | The Guild Is Fun |
| TGOF | The Great Over Fifties |
| TGW | The Greatest Warriors |
| THA | Texas Horseowners Association |
| THAC0 | To Hit Armor Class 0 (Advanced Dungeons & Dragons) |
| TIARA | The Irish Ancestral Research Association |
| TIB | Two-In-a-Box model |
| TLAD | The Lost and Damned (GTA) |
| TM | Trombone |
| TMMC | Todo Moto Motorcycle Club |
| TNCTC | Tennessee Classic Truck Club |
| TOCC | Tricked Out Car Club |
| TOLO | This One Last One |
| TOS | Tennessee Ornithological Society |
| TOS | Texas Ornithological Society |
| TPG | Torrey Pines Gulls |
| TransFan | Transformers Fan |
| TRGP | Tabletop RolePlaying Game |