| Sindelar Tree Service INC | Timothy John Alfred Sindelar | — | (209) 559 0124 | Tree | Sonora · Tuolumne County | — | — |
| Skelton Construction | Barry Craig Skelton | — | (209) 855 2166 | GC, remodel, ADU | Groveland · Tuolumne County | — | — |
| Slevin Electric | Frank Patrick Slevin | — | (209) 288 2386 | Electricians | Sonora · Tuolumne County | — | — |
| Smallman Construction & Electric | Smallman Construction & Electric | — | (209) 800-0097 | Electricians | Sonora · Tuolumne County | — | — |
| Smci | David Carlos Benton | — | (209) 988 2282 | Electricians | Sonora · Tuolumne County | — | — |
| Smci / Obayashi Joint Venture | Corporation Obayashi | — | (209) 928 1900 | Tree | Sonora · Tuolumne County | — | — |
| Smith Pro Painting Co | James Wesley Ii Smith | — | (209) 743 6112 | Windows, patio, painters | Sonora · Tuolumne County | — | — |
| Sohst Construction Co | Ronald Oliver Sohst | — | (209) 962 5504 | GC, remodel, ADU | Big Oak Flat · Tuolumne County | — | — |
| Sol Training | Sol Training | — | (650) 681 9445 | Electricians | Groveland · Tuolumne County | — | — |
| Solomon's Gardens INC | George Winthrop Kirk | — | (209) 533 9425 | Windows, patio, painters | Mi-wuk Village · Tuolumne County | — | — |
| Sonora Painting | Sonora Painting | — | (951) 310 2070 | Windows, patio, painters | Jamestown · Tuolumne County | — | — |
| Sonora Pest Control | Sonora Pest Control | — | (209) 540-3667 | Pest, tile roofs | Sonora · Tuolumne County | — | — |
| Sonora Tractor Service | Monte Thomas Gray | — | (209) 352 1156 | Other | Jamestown · Tuolumne County | — | — |
| Sonora Window Washing | Sonora Window Washing | — | (661) 300-1226 | Windows, patio, painters | Sonora · Tuolumne County | — | — |
| Sorini Construction | Michael Anthony Sorini | — | (209) 289 8878 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Spartan Welding | Spartan Welding | — | (209) 559 0910 | Other | Sonora · Tuolumne County | — | — |
| Stacy J Mackey Construction | Stacy James Mackey | — | (209) 225 0900 | GC, remodel, ADU | Tuolumne · Tuolumne County | — | — |
| Standard Sierra Painting | Standard Sierra Painting | — | (209) 591 3975 | Windows, patio, painters | Sonora · Tuolumne County | — | — |
| Stanton Construction Company | Michael William Stanton | — | (925) 250 4251 | GC, remodel, ADU | Jamestown · Tuolumne County | — | — |
| Step Up Property Management | Step Up Property Management | — | (209) 532-7837 | Property managers | Sonora · Tuolumne County | — | — |
| Stephen M Weeks | Stephen M Weeks | — | (209) 694 8453 | Other | Sonora · Tuolumne County | — | — |
| Stephen Murphy Construction | Stephen Edward Murphy | — | (415) 786 3391 | GC, remodel, ADU | Mi-wuk Village · Tuolumne County | — | — |
| Stephen Rodriguez Construction | Stephen Charles Jr Rodriguez | — | (209) 206 6420 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Steven M Vaccarezza | Steven M Vaccarezza | — | (209) 559 4894 | GC, remodel, ADU | Jamestown · Tuolumne County | — | — |
| Steven R Moreno | Steven R Moreno | — | (209) 770 6327 | Electricians | Sonora · Tuolumne County | — | — |
| Steven W Tucker | Steven W Tucker | — | (209) 743 2181 | GC, remodel, ADU | Tuolumne · Tuolumne County | — | — |
| Stevens Construction | Anthony Randall Stevens | — | (209) 743 5887 | GC, remodel, ADU | Jamestown · Tuolumne County | — | — |
| Stone Electric | Richard Randall Stone | — | (209) 352 0740 | Electricians | Twain Harte · Tuolumne County | — | — |
| Straightline Fencing | Rayvon Larry Keenom | mainestraightline@gmail.com | (207) 299-2055 | Other | Sonora · Tuolumne County | — | — |
| Streamline Inspections | Streamline Inspections | — | (209) 801-2080 | Inspectors | Twain Harte · Tuolumne County | — | — |
| Strong Painting | Strong Painting | — | (209) 768 9530 | Windows, patio, painters | Twain Harte · Tuolumne County | — | — |
| Structure | Brandon John Clements | — | (209) 559 1285 | GC, remodel, ADU | Tuolumne · Tuolumne County | — | — |
| Sund Construction Co | Eric Carl Sundblad | — | (209) 288 8559 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Sunset Hills Contracting | Marty Lee Hurley | — | (209) 743 4910 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| T - N - T Mini Tractor | Tommy Richard Thomason | — | (209) 984 5010 | Other | Jamestown · Tuolumne County | — | — |
| T Chase Construction | Thornton Chase Bulkin | — | (209) 454 7482 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| T D C Troy Devereux Construction | Troy Vincent Devereux | — | (209) 743 7261 | GC, remodel, ADU | Jamestown · Tuolumne County | — | — |
| T R Z | T R Z | — | (209) 986 2355 | GC, remodel, ADU | Pinecrest · Tuolumne County | — | — |
| T-n-t Excavating | T-n-t Excavating | — | (209) 743 4213 | Other | Jamestown · Tuolumne County | — | — |
| Tanko Bros INC | Marvin Kent Tanko | — | (209) 532 7797 | Other | Sonora · Tuolumne County | — | — |