| The New Om | Manitowoc County | Club |
| The Red Line Chronicles | Greater Seacoast | Club |
| The TEAM - SoCalCross | Altadena | Club |
| Three Rivers Velo Sport | Fort Wayne | Club |
| THUMB MTB Club | Eastern Panhandle (thumb) | Club |
| Toledo Area Mountain Bike Association | Toledo | Club |
| Tour De Lanta - Urban Singletrack MB Club | Atlanta | Club |
| Tracks | Lakeside | Club |
| Trail Advocacy Coalition of the Ouachitas | | |
| Trail Masons | Wyandotte County | Club |
| Trail of Legends Association (TOLA) | Wetumpka | Club |
| TRAIL Washington | Leavenworth | Club |
| Trails 2000 | Durango | Club |
| Tri-County Mountain Biking Association (TCMBA) | Madison | Club |
| Tri-State Mountain Bike Riders (TMBR) | Dubuque | Club |
| Triad Mountain Bike Group (MeetUp)**defunct** | Triad (Winston-Salem/Greensboro/High Point) | Club |
| Triangle Off-road Cyclists (TORC) | Raleigh / Durham / Chapel Hill | Club |
| TRIBE - Estacada Youth Mountain Biking Club | | |
| Tucson Off-Road Cyclists and Activists (TORCA) | Tucson | Club |
| Tuff Riders Mountain Bike Club | Los Alamos | Club |
| Tunica Trail Riders | | Club |
| U-LOCK MOB MTB | Downtown Los Angeles | Club |
| Ukiah Valley Trail Group | Ukiah | Club |
| United Mountain Bike of Washington | Seattle | Club |
| Upper Chattahoochee Cycling Club SORBA (UC3) | Cornelia | Club |
