| Think Inside INC | Cathal Gerard Kelly | — | (310) 850 2403 | Other | Santa Rosa · Sonoma County | — | — |
| Third Pig Builder INC | James Stewart| Mac Killop Jim Mac Killop | jsmackillop@gmail.com | (707) 205 7260 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Thomas A Lenny | Thomas A Lenny | — | (707) 696 6850 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Thomas Anderson & Co | Thomas Eugene Anderson | — | (707) 938 2146 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Thomas Building Group | Thomas Michael Young | — | (415) 676 7277 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Thomas Burton Niewald | Thomas Burton Niewald | — | (707) 696 2659 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Thomas E Bottorff General Contractor | Thomas E Bottorff General Contractor | — | (707) 981 6137 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Thomas Holland | Thomas Holland | — | (707) 477 3914 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Thomas Landscapes | Thomas Landscapes | — | (707) 337 9847 | Windows, patio, painters | Healdsburg · Sonoma County | — | — |
| Thomas Nobles | Thomas Nobles | — | (707) 696 6422 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Thomas Petersen | Thomas Petersen | — | (650) 302 3591 | Other | Sonoma · Sonoma County | — | — |
| Thomas Roth | Thomas Roth | — | (650) 534 4053 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Thomas W Cargile | Thomas W Cargile | — | (707) 953 6579 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Thompson Construction INC | Dennis Bruce Thompson | tthompson1024@gmail.com | (707) 433 8486 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Thompson Excavating & General Engineering | Thompson Excavating & General Engineering | — | (707) 292 5141 | Other | Santa Rosa · Sonoma County | — | — |
| Thomsen Construction Company | Richard Elwood Thomsen | — | (707) 953 2396 | Other | Santa Rosa · Sonoma County | — | — |
| Thomson Contracting INC | Dennis Keith Thomson | — | (707) 766 8051 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Thomson Window Service | Kelly James Thomson | — | (707) 570 0789 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Thomson-ojeda Construction | Patrick William Thomson-ojeda | — | (707) 888 8636 | GC, remodel, ADU | Cloverdale · Sonoma County | — | — |
| Thor Cary Electric INC | Thor Lei Cary | — | (707) 836 0494 | Electricians | Windsor · Sonoma County | — | — |
| Thornley Associates INC | Thomas Kenneth Thornley | — | (707) 227 9920 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Thoroughbred Waterproofing | Thoroughbred Waterproofing | — | (707) 578 8678 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Thorsted Construction INC | Jack Dillon Thorsted | — | (707) 246 1346 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Three Branches Tree Co | Nicholas Rouhan Earley | — | (707) 978 8073 | Tree | Occidental · Sonoma County | — | — |
| Three Lions Remodeling | Three Lions Remodeling | rubenmonterroso17@gmail.com | (415) 497 3513 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Three Trees Design Build | Three Trees Design Build | — | (707) 772 9268 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Thrive Construction Group | Gregory Dow Beale | — | (707) 827 9600 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Throne Electric | Alfredo Guzman Castaneda | — | (707) 332 4542 | Electricians | Rohnert Park · Sonoma County | — | — |
| Thurlow Construction & Design | Jon Vincent Thurlow | — | (707) 292 7866 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Thurston Construction Co INC | David Scott Thurston | — | (707) 236 0468 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| Tibbetts Construction | Brian Dale Tibbetts | tibbettsconstruction@outlook.com | (707) 350 7723 | GC, remodel, ADU | Guerneville · Sonoma County | — | — |
| Tight Access Excavation INC | Michael Anthony Sedano | — | (707) 795 0369 | Other | Sebastopol · Sonoma County | — | — |
| Tile Care | Tile Care | — | (707) 544 1162 | Other | Santa Rosa · Sonoma County | — | — |
| Tile Tech | Tile Tech | — | (415) 685 8299 | Other | Petaluma · Sonoma County | — | — |
| Tile Unlimited | Tile Unlimited | — | (707) 364 7514 | Other | Petaluma · Sonoma County | — | — |
| Tillman Construction INC | Tanya Carol Tillman | — | (707) 484 4960 | Other | Santa Rosa · Sonoma County | — | — |
| Tim Brown Enterprises | Timothy John Brown | — | (707) 849 0445 | GC, remodel, ADU | Forestville · Sonoma County | — | — |
| Tim Grogan Builders INC | Timothy Patrick Grogan | — | (707) 829 0509 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Tim Gunderson Electric | Timothy Andrew Gunderson | — | (707) 799 4034 | Electricians | Santa Rosa · Sonoma County | — | — |
| Tim Mc Closkey Electric INC | Timothy Michael Mc Closkey | — | (707) 953 0679 | HVAC | Petaluma · Sonoma County | — | — |