| Name | School | Sub-Type |
|---|---|---|
| Swati Joshi | Classification 4 | |
| Taiwanese American Foundation of Greater Seattle | Classification 3 | |
| Taiwanese Assn of Greater Seattle | Classification 3 | |
| Tanjavur Dance School | Classification 3 | |
| TapRoot Performers | ||
| Tayon Ary-Turner | Classification 2 | |
| Teaching and Learning | ||
| Team Fuego | Chinook Middle School | |
| Tech Mahindra | ||
| Tech Smart Kids | Chinook Middle School | |
| TechSmart Kids | ||
| Telugu Bharati | Classification 3 | |
| The China Press | Classification 4 | |
| The Countdown Competition | ||
| The Little School | Classification 3 | |
| Theater Chameleon | ||
| Three Cedars Waldorf School | Classification 3 | |
| Tinali LLC | ||
| Tiranga | ||
| Title IX Committee | ||
| Totem select basketball | Classification 3 | |
| Touchdown Media Inc. | ||
| Town of Beaux Arts | ||
| Towne Square Condos | ||
| Transition | Classification 1 | |
| Triangle Pool | ||
| Tzu Chi Academy | Classification 3 | |
| Tzu-Chi Foundation; Seattle Branch | Classification 3 | |
| US Lacrosse - Washington | ||
| UTSAV |
