| Abbreviation | Definition |
|---|---|
| TTOB | Two Towns One Book |
| TTOC | TT Owners Club |
| TTTI | Trust Technical Training Institute (Bangladesh) |
| TTYF | Truman Township Youth Foundation |
| TU | Trout Unlimited |
| TUBA | Tubists Universal Brotherhood Association |
| TUC | Trout Unlimited Canada |
| TUF | Taiwanese United Fund of Southern California |
| TUNC | Tufts University Nutrition Center |
| TUO | Trout Unlimited On-line |
| TURANT | The Turkish American Association of Northern Texas |
| TURF | Trail Users Rights Foundations |
| TUV | Technischer Überwachungs-Verein |
| TUW | Trident United Way |
| TVAC | Thalidomide Victims Association of Canada |
| TVE | TeleVision trust for the Environment |
| TVEAP | Asia Pacific Television for the Environment |
| TVNTN | Teach VietNam Teacher's Network |
| TVTA | Thames Valley Trail Association (Ontario) |
| TVWA | Temecula Valley Winegrowers Association |