| Six Eight Electric LLC | Nathaniel Lee Lofton | six.eightelectric@gmail.com | (707) 592 6348 | Electricians | Vacaville · Solano County | — | — |
| Sk Plumbing Company | Shayea Abbas Korin | — | (510) 938 4079 | Other | Rio Vista · Solano County | — | — |
| Skillie Constructors | Skillie Constructors | — | (707) 515 9353 | Other | Elmira · Solano County | — | — |
| Skog Construction | Casey Aaron Skog | — | (707) 301 3749 | GC, remodel, ADU | Dixon · Solano County | — | — |
| Skopos Construction | James Michael Skopos | — | (916) 224 1363 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Sky View Framing | Sky View Framing | — | (707) 689 3724 | Electricians | Vacaville · Solano County | — | — |
| Skyen Landscaping | Skyen Landscaping | — | (510) 333 3919 | Windows, patio, painters | Suisun City · Solano County | — | — |
| Skyhawk Electric | James Allan Jr Krause | — | (707) 624 6056 | Electricians | Vacaville · Solano County | — | — |
| Skylark Tile | Skylark Tile | — | (801) 628 5262 | Other | Vallejo · Solano County | — | — |
| Skylight Electrical Service | Miguel Angel Amezquita Robles | support@skylightelectricalservice.com | (707) 515 5503 | Electricians | Fairfield · Solano County | — | — |
| Skyridge Plumbing | Skyridge Plumbing | oscaregomez2003@yahoo.com | (707) 344 0224 | Other | Vacaville · Solano County | — | — |
| Slc INC | David Michael Davis | — | (707) 249 3419 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Slp Landscape Solution | Slp Landscape Solution | — | (707) 580 0918 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Slump Concrete INC | Juan Carlos Pelz | — | (707) 655 2317 | Other | Fairfield · Solano County | — | — |
| Smart Concept Flooring INC | Andres Carrillo | — | (510) 861 2868 | Other | Vallejo · Solano County | — | — |
| Smart Plumbing Project INC | Jimmy Omar Vasquez | — | (415) 987 4093 | Other | Vallejo · Solano County | — | — |
| Solana Beach Building Permits | Solana Beach Building Permits | — | (858) 720-4450 | Other roofers | Solana Beach · Solano County | — | — |
| Solana Flooring | Solana Flooring | — | (858) 755-7363 | GC, remodel, ADU | Solana Beach · Solano County | — | — |
| Solano Bay Painting | Solano Bay Painting | — | (415) 819 8079 | Windows, patio, painters | Vacaville · Solano County | — | — |
| Solano Construction Co INC | Solano Construction Co INC | — | (707) 450-0100 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Solano County Roofing INC | David Ryan Miller | — | (707) 864 6000 | Other roofers | Fairfield · Solano County | — | — |
| Solano Custom Concrete INC | Juan Francisco Reyes Garcia | — | (707) 689 2347 | Other | Dixon · Solano County | — | — |
| Solano Diversified Services INC | Daniel Robert Davisson | — | (707) 552 9443 | Windows, patio, painters | Vallejo · Solano County | — | — |
| Solano Drywall | Solano Drywall | info@solanodrywall.com | (951) 796-3136 | Other | Suisun City · Solano County | — | — |
| Solano Electric And Controls | Thomas Theron Brown | — | (707) 724 8242 | Electricians | Vacaville · Solano County | — | — |
| Solano Exceptional Roofing | Solano Exceptional Roofing | — | (707) 414-8720 | Other roofers | Vallejo · Solano County | — | — |
| Solano Glass Company Incorporated | Curtis Eugene Branson | service@solanoglass.com | (707) 425 6461 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Solano Heating & Air Conditioning Inc. | Solano Heating & Air Conditioning Inc. | — | (707) 416-0845 | HVAC | Suisun City · Solano County | — | — |
| Solano Hydroseed INC | Gary Wayne La Mar | — | (707) 450 9046 | Windows, patio, painters | Vacaville · Solano County | — | — |
| Solano Painting | Solano Painting | solanopaintingbros@gmail.com | (707) 290-4409 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Solano Painting Bros Incorporated | Salvatore Christian Sammartino | solanopaintingbros@gmail.com | (707) 386 7251 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Solano Property Management | Solano Property Management | — | (707) 447-8501 | Property managers | Vacaville · Solano County | — | — |
| Solano Rot | Solano Rot | — | (707) 365 5115 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Solano Screen Solutions | Solano Screen Solutions | — | (707) 392 0024 | Other | Vacaville · Solano County | — | — |
| Solano Seamless INC | Frank Richard Ables | — | (707) 449 4577 | Other | Vacaville · Solano County | — | — |
| Solano Signs | Aaron Donald Cradduck | sales@solanosigns.com | (707) 427 0400 | Other | Fairfield · Solano County | — | — |
| Solano Tile | Jose Luis Ramirez Godinez | — | (707) 392 8730 | Other | Vacaville · Solano County | — | — |
| Solano-napa Habitat For Humanity INC | Jamie Foster Calderwood | — | (707) 422 1948 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Solid Foundation Construction | Michael Todd Sorenson | — | (707) 384 9909 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Solid Rock Paving | George George Stanley | — | (408) 744 6217 | Other | Vacaville · Solano County | — | — |