| Abbreviation | Definition |
|---|---|
| TSAI | Tourette Syndrome Association, Inc. |
| TSAL | To Save A Life |
| TSANJ | Tourette Syndrome Association of New Jersey, Inc. |
| TSA-O | Tourette Syndrome Association of Ohio |
| TSA-USA | Tourette Syndrome Association of the United States of America |
| TSCA | Texas Speech Communication Association |
| TSE | The Seeing Eye |
| TSF | The Sonic Foundation |
| TSF | The Steppingstone Foundation |
| TSF | Tidewater Scholarship Foundation |
| TSFI | Tidewater Scholarship Foundation, Inc. |
| TSH | Tierra Santa Home |
| TSMO | Transnational Social Movement Organization |
| TSP | The Soup Project |
| TSSI | Tierra Santa Support, Inc. |
| TTAF | The Three Aid Foundation |
| TTDC | Trinidad and Tobago Debates Commission |
| TTE | Television Trust for the Environment |
| TTEC | Triangle Technology Executives Council |
| TTEF | Transcending Through Education Foundation |