| Sps Painting INC | Pontifice Sergio | — | (925) 759 3103 | Windows, patio, painters | Pittsburg · Contra Costa County | — | — |
| Sps Remodeling & Painting INC | Juan Enrique Salazar | — | (925) 759 3103 | GC, remodel, ADU | Pittsburg · Contra Costa County | — | — |
| Spurr Construction | Michael Robert Spurr | — | (925) 895 8556 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Spurvine Construction | Jeffrey O'neil Irvine | — | (949) 500 7019 | GC, remodel, ADU | Bethel Island · Contra Costa County | — | — |
| Sq1sales LLC DBA Shipley Pools | Johnny Ray Shipley | — | (415) 710 8022 | Pool | Pinole · Contra Costa County | — | — |
| Square Foot Floor & Tile | Square Foot Floor & Tile | — | (925) 567 7006 | Other | Concord · Contra Costa County | — | — |
| Square Level Plumb INC | Gregory Blaine Skeen | — | (925) 768 1703 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Sridhar Construction INC | Sridhar Nikhil | — | (858) 248 0957 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Srk Builders LLC | Radoslav Ivkov Ayvazov | — | (925) 577 6747 | Electricians | Concord · Contra Costa County | — | — |
| Srk Electric | Sean Robert King | contact@srkelectric.com | (925) 768 6682 | Electricians | Clayton · Contra Costa County | — | — |
| Sry Construction | Sadi Galila | — | (510) 620 0722 | Electricians | El Cerrito · Contra Costa County | — | — |
| Ssr Tree Service INC | Melvin Omar Guardado | — | (415) 671 5106 | Tree | Bay Point · Contra Costa County | — | — |
| St Thomas Construction INC | Thomas Augustine Baldacci | — | (925) 328 1000 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| Stack Construct | Martin Albert Miller | — | (925) 849 6390 | GC, remodel, ADU | Alamo · Contra Costa County | — | — |
| Stacy L Silva Construction | Stacy Lynn Silva | — | (916) 761 3123 | Other | Byron · Contra Costa County | — | — |
| Stairs Steps & Structures | John Scott Davis | — | (510) 691 1620 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Stalls & Stripes INC | Robert James Taylor | — | (925) 783 4088 | Other | Oakley · Contra Costa County | — | — |
| Stan Tolocko Painting | Stan Tolocko Painting | — | (858) 531 1475 | Windows, patio, painters | Discovery Bay · Contra Costa County | — | — |
| Stanleys Pro Construction INC | Pokazanev Stanislav | — | (530) 407 8484 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Stanton Plumbing | Patrick Edward Stanton | — | (925) 349 4602 | Other | Concord · Contra Costa County | — | — |
| Stanworth Signs | Stanworth Signs | — | (925) 360 4556 | Other | Walnut Creek · Contra Costa County | — | — |
| Star Bright Pool And Spa Care | Aaron James Ginkens | — | (925) 595 9586 | Pool | Concord · Contra Costa County | — | — |
| Star Media Consultants | Star Media Consultants | — | (925) 708 8014 | Other | Walnut Creek · Contra Costa County | — | — |
| Star Waterproofing And Roofing INC | Gelber Geobani Ramirez | — | (510) 710 4105 | Other roofers | Walnut Creek · Contra Costa County | — | — |
| Starkey Home Repairs | Starkey Home Repairs | — | (925) 517 5563 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Statewide Construction | Murariu Petru | — | (510) 867 7090 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Staycool Patio Covers INC | William Howard Claypool | staycoolpatiocoversinc@gmail.com | (925) 457 6185 | GC, remodel, ADU | Bethel Island · Contra Costa County | — | — |
| Stealth Enterprises INC | Peter Gustav Scheideman | — | (925) 408 6466 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Stealth Leak Specialists INC | Nicholas Ryan Petersen | — | (925) 342 2296 | Other | Oakley · Contra Costa County | — | — |
| Steele Electric | Scott Morgan Steele | — | (925) 525 4612 | Electricians | Oakley · Contra Costa County | — | — |
| Steen Construction INC | Eric Michael Steen | — | (925) 864 3784 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Stefano's Plumbing & Drain | Stefano's Plumbing & Drain | — | (925) 383 8506 | Other | Lafayette · Contra Costa County | — | — |
| Steinberg Electric LLC | Matthew Thomas Steinberg | info@steinbergelectric.com | (925) 963 1727 | Electricians | Concord · Contra Costa County | — | — |
| Steindorf Limited Very Nice Pools | Steindorf Limited Very Nice Pools | — | (925) 283 5180 | Pool | Lafayette · Contra Costa County | — | — |
| Stellar Construction | Madeeha Kibriya | — | (626) 260 2849 | Other roofers | Brentwood · Contra Costa County | — | — |
| Step Ahead Construction Services | Douglas Alan Brumley | — | (925) 200 5627 | GC, remodel, ADU | Knightsen · Contra Costa County | — | — |
| Step By Step Home Improvement | Step By Step Home Improvement | — | (925) 324 0438 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Stephanie R Seeno | Stephanie R Seeno | — | (925) 932 4655 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Stephen E Pizzi INC | Stephen Ellis Pizzi | — | (650) 533 3737 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Stephen R Duffel DBA Diablo Valley Construction | Stephen Ray Duffel | — | (925) 209 4832 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |