| Strong Property Management | Strong Property Management | — | (707) 933-9151 | Property managers | Sonoma · Solano County | — | — |
| Stuart N Reid DBA Snr Renovations | Snr Renovations | — | (707) 953 1525 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Stucco Designs | Stucco Designs | — | (707) 685 9122 | Other | Vacaville · Solano County | — | — |
| Sublime Painting | Sublime Painting | — | (951) 623 9110 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Sublime-crm Construction Remodeling Maintenance | Ibarra Vazquez Edwin | — | (707) 685 5536 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Suisun Valley Plumbing | Suisun Valley Plumbing | — | (707) 208 0866 | Other | Fairfield · Solano County | — | — |
| Suisun Valley Sheet Metal INC | Andrew Eric Levengood | — | (707) 426 5493 | HVAC | Suisun City · Solano County | — | — |
| Sully & Sons Concrete/landscape | Kevin James Sullivan | — | (510) 363 7871 | Windows, patio, painters | Vallejo · Solano County | — | — |
| Summerfield Construction | Samurai Edward Summerfield | — | (707) 315 9215 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Summit Crane | Curt George Posthuma | interested@domainmarket.com | (707) 448 6740 | Other | Vacaville · Solano County | — | — |
| Summit Energy | Timothy Martin Brown | — | (530) 304 9429 | Electricians | Dixon · Solano County | — | — |
| Summit Roofing | William James Moy | — | (707) 451 0162 | Other roofers | Suisun · Solano County | — | — |
| Sunamp Electric INC | Rabih Youssef Hammana | — | (831) 706 6335 | Electricians | Vallejo · Solano County | — | — |
| Sunhaven Builders | Sunhaven Builders | — | (707) 720 5506 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Sunlightning Heating & Air | Sunlightning Heating & Air | — | (707) 315 1277 | HVAC | Vallejo · Solano County | — | — |
| Sunmaster | Peter Denson Mott | — | (707) 253 9177 | Other | Vallejo · Solano County | — | — |
| Sunrise Painting | Sunrise Painting | — | (707) 580 7898 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Sunset Landscaping And Construction | Julio Yanez Sotuela | — | (530) 574 3029 | GC, remodel, ADU | Dixon · Solano County | — | — |
| Sunset Pools INC | Ramon Espinosa | — | (707) 312 0637 | Pool | Suisun City · Solano County | — | — |
| Super Electric | Gerhard Wolfgang Loos | — | (707) 648 3333 | Electricians | Vallejo · Solano County | — | — |
| Superior Concrete Designs | Superior Concrete Designs | — | (707) 641 5656 | Other | Vallejo · Solano County | — | — |
| Superior Painting Earthwork Excavating | Superior Painting Earthwork Excavating | — | (707) 226 1578 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Superior Plumbing INC | Clifford Jacob Jr Maul | — | (707) 249 1919 | Other | Fairfield · Solano County | — | — |
| Superior Sandblasting | Superior Sandblasting | — | (415) 621 3111 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Sutton Construction INC | Steven James Sutton | — | (707) 422 8242 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Suulutaaq INC | John David Hurd | joel.zeni@suulutaaq.com | (541) 510-0505 | GC, remodel, ADU | Suisun City · Solano County | — | — |
| Swank Construction INC | Richard John Swank | — | (707) 446 8808 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Swedish Wallpaper Installation LLC | Erik Tommy Stromberg | — | (707) 592 2242 | Windows, patio, painters | Vacaville · Solano County | — | — |
| Sweeney Construction Company | Patrick Jon Sweeney | — | (707) 451 7426 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Sweetwater Construction INC | Richard Leo Williams | — | (707) 554 8824 | Other | Benicia · Solano County | — | — |
| Swensson Construction | Richard Calvin Swensson | — | (707) 386 2529 | GC, remodel, ADU | Rio Vista · Solano County | — | — |
| Syber Fiber | Stephen Russell Jr Stukas | support@syberfiber.com | (888) 793 4237 | Other | Vallejo · Solano County | — | — |
| T & J Elite Tile INC | Delgadillo Eliseo Maldonado | — | (707) 704 0495 | Other | Fairfield · Solano County | — | — |
| T & M Home Services | Thomas Donald Brooks | — | (707) 557 3176 | GC, remodel, ADU | Vallejo · Solano County | — | — |
| T E H Const Co | Thomas Eddie Hatton | — | (707) 974 7897 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| T Hagen Construction | Terrell Ned Hagen | — | (925) 719 4229 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| T J & M Masonry | Yolanda Gonzalez Chavez | info@indiantypefoundry.com | (707) 746 8483 | GC, remodel, ADU | Benicia · Solano County | — | — |
| T J Communications | T J Communications | — | (707) 704 6943 | Other | Vallejo · Solano County | — | — |
| T K C Quality Construction | Steven Andrew Lucas | — | (707) 447 7797 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| T N T Construction | Anthony William Sanchez | — | (707) 645 7299 | HVAC | Vallejo · Solano County | — | — |