| Santacruz Flooring | Santacruz Flooring | info@santacruz-flooring.com | (650) 291 0467 | Other | San Pablo · Contra Costa County | — | — |
| Santana Landscape & Maintenance INC | Santana Gallegos Eucebio | — | (925) 285 0099 | Windows, patio, painters | Bay Point · Contra Costa County | — | — |
| Santana's Building And Design | Santana's Building And Design | — | (510) 253 5367 | GC, remodel, ADU | El Cerrito · Contra Costa County | — | — |
| Santi Painting INC | Nubia Carolina Parada Solis | info@santipainting.com | (415) 559 9395 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Santillan Construction INC | Moran Erik Santillan | — | (415) 361 3290 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| Santizo Heating & Air Conditioning | Santizo Heating & Air Conditioning | — | (510) 860 7371 | HVAC | Richmond · Contra Costa County | — | — |
| Santoyo Construction | Francisco Javier Santoyo | — | (415) 630 3389 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Sapphire Pool Service INC | Evan Christopher Smith | — | (925) 947 1484 | Pool | Walnut Creek · Contra Costa County | — | — |
| Sarah Ray Design INC | Sarah Elise Ray | — | (510) 812 7498 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Sargsyan | Sargsyan Arayik | — | (925) 451 2202 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Sarullo Electric INC | John Joseph Sarullo | — | (408) 393 0386 | Electricians | San Ramon · Contra Costa County | — | — |
| Sausal Corporation | Josh Ward | — | (925) 568 2200 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Savant Arborists | Savant Arborists | office@savantarborists.com | — | Tree | Contra Costa · Contra Costa County | — | — |
| Saveon Incorporated | Allen H Yazdi | — | (510) 601 7077 | Windows, patio, painters | El Cerrito · Contra Costa County | — | — |
| Savior Energy INC | Donald Warren Leaman | — | (925) 383 7400 | Electricians | Danville · Contra Costa County | — | — |
| Savvyteks Heating And Air Conditioning | Christopher Thomas George | — | (925) 693 7227 | HVAC | San Ramon · Contra Costa County | — | — |
| Sawatzky Builders INC | John Erich Sawatzky | — | (925) 354 9419 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Sawdust Remodeling | Dustin Harold Crenshaw | — | (510) 685 9210 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Sayman Mechanical Systems INC | Aziz Rashid Sayyid | — | (925) 494 4225 | HVAC | Concord · Contra Costa County | — | — |
| Sb Construction | Nicholas Ryan Shalchi | — | (925) 813 2673 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |
| Sb Flooring | Sb Flooring | — | (925) 481 6591 | Other | Antioch · Contra Costa County | — | — |
| Sc Home Repair | Sc Home Repair | — | (925) 826 7863 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Sca Controls | Sca Controls | — | (510) 599 1608 | Electricians | Brentwood · Contra Costa County | — | — |
| Scanlan Construction | Darren Lee Scanlan | — | (510) 919 4334 | GC, remodel, ADU | Hercules · Contra Costa County | — | — |
| Schaedel Painting | Schaedel Painting | — | (510) 495 4612 | Windows, patio, painters | Richmond · Contra Costa County | — | — |
| Schaefer Construction LLC | Tawny Lea Schaefer | — | (925) 586 1234 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Schaefer's Painting | Schaefer's Painting | — | (925) 260 6065 | Windows, patio, painters | Clayton · Contra Costa County | — | — |
| Scheer Security Alarm Systems INC | Douglas Alexander Scheer | — | (925) 625 7580 | Electricians | Oakley · Contra Costa County | — | — |
| Schicker Luxury Bath | Chad Jesse Conley | — | (925) 676 8422 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Schicker Luxury Shower Doors INC | James Joseph Matthews | — | (925) 676 5040 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Schroeder Woodwerks | Schroeder Woodwerks | schroederwoodwerks@gmail.com | (925) 471 6617 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Schurr Is Nice Masonry | Schurr Is Nice Masonry | — | (925) 956 3871 | Other | Concord · Contra Costa County | — | — |
| Scolari Marble & Granite INC | Gino Ernest Scolari | — | (510) 758 7482 | Other | Pinole · Contra Costa County | — | — |
| Scott Busby Construction INC | James Junior Busby | busby.construction@yahoo.com | (925) 228 0522 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Scott Carr Co | Scott Martin Carr | — | (925) 376 7431 | Other | Moraga · Contra Costa County | — | — |
| Scott Chandler Contractor | Scott Chandler Contractor | — | (925) 413 5407 | GC, remodel, ADU | Alamo · Contra Costa County | — | — |
| Scott Groschel | Scott Groschel | — | (925) 487 6515 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Scott Henry Hagen | Scott Henry Hagen | — | (925) 207 3591 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| Scott Kaiser Co | Scott Brandon Kaiser | — | (925) 381 7261 | GC, remodel, ADU | Pittsburg · Contra Costa County | — | — |
| Scott Lloyd | Scott Lloyd | — | (925) 586 2222 | GC, remodel, ADU | Concord · Contra Costa County | — | — |