| Solano's Painting Company | Echeverria Sergio Solano | info@solanospainting.com | (209) 227 9709 | Windows, patio, painters | Modesto · Stanislaus County | — | — |
| Solecon Industrial Contractors INC | Brandon Darrell Top | — | (209) 572 7390 | HVAC | Modesto · Stanislaus County | — | — |
| Solid Solutions Construction Services INC | Kathleen Deborah Prouty | — | (209) 602 3240 | Other roofers | Modesto · Stanislaus County | — | — |
| Solid Vision Restorations | Solid Vision Restorations | — | (209) 321 5708 | GC, remodel, ADU | Ceres · Stanislaus County | — | — |
| Solis Construction | Frank Solis | — | (209) 847 5507 | GC, remodel, ADU | Oakdale · Stanislaus County | — | — |
| Solo Construction LLC | Rodriguez Oscar Garcia | — | (209) 412 1965 | GC, remodel, ADU | Modesto · Stanislaus County | — | — |
| Solo Gen Construction | Frank Ruben Solorio | — | (209) 324 1373 | GC, remodel, ADU | Riverbank · Stanislaus County | — | — |
| Solves All Engineering | Solves All Engineering | — | (925) 899 8123 | Other | Oakdale · Stanislaus County | — | — |
| Sonitrol Security | Sonitrol Security | jrussell@sonitrolsecurity.com | — | Alarm and generators | Modesto · Stanislaus County | — | — |
| Sons Construction & Custom Fencing | Michael Merle Sons | — | (209) 848 2035 | GC, remodel, ADU | Oakdale · Stanislaus County | — | — |
| Sosa Electric | Efren Medina Sr Sosa | — | (209) 522 7350 | Electricians | Modesto · Stanislaus County | — | — |
| Soto Construction | Jose Angel Soto | — | (209) 872 0087 | GC, remodel, ADU | Modesto · Stanislaus County | — | — |
| Sparcsound | Joshua David Belokonny | — | (209) 918 5212 | Other | Modesto · Stanislaus County | — | — |
| Sparky's Electric | Gaxiola Cesar | — | (209) 380 4377 | Electricians | Modesto · Stanislaus County | — | — |
| Special Things Sheetmetal Co | David Louie Lamott | — | (408) 421 4258 | Other | Hughson · Stanislaus County | — | — |
| Specialized Services | Marc Anthony Speckens | interested@domainmarket.com | (209) 678 6199 | GC, remodel, ADU | Turlock · Stanislaus County | — | — |
| Specialized Tile & Stone | Specialized Tile & Stone | — | (209) 587 0895 | Other | Modesto · Stanislaus County | — | — |
| Specialized Trades | Specialized Trades | — | (800) 889 4129 | HVAC | Oakdale · Stanislaus County | — | — |
| Specialty Tile INC | Darrel Keith Kaml | — | (209) 579 2696 | Other | Salida · Stanislaus County | — | — |
| Speedy Construction Corporation | Antonio Ayala | — | (209) 613 5120 | GC, remodel, ADU | Hughson · Stanislaus County | — | — |
| Spring Crest Drapery | Spring Crest Drapery | — | (209) 527 1230 | Other | Modesto · Stanislaus County | — | — |
| Sr Rios Landscape Services INC | Jorge Alberto Rios Alejandre | — | (209) 402 0761 | Windows, patio, painters | Salida · Stanislaus County | — | — |
| Srr General Engineering Constructors INC | Rivas Sergio Reyes | — | (408) 628 9459 | GC, remodel, ADU | Ceres · Stanislaus County | — | — |
| St Clair Plumbing | St Clair Plumbing | — | (209) 541 5844 | Other | Modesto · Stanislaus County | — | — |
| Staal Construction And Fabrication INC | Daniel John Staal | — | (209) 764 8652 | GC, remodel, ADU | Oakdale · Stanislaus County | — | — |
| Staffero Mechanical INC | John Mitchell Staffero | — | (209) 410 0922 | HVAC | Turlock · Stanislaus County | — | — |
| Stain Masters & Painters INC | Jose Luis Vega Oseguera | — | (510) 589 5933 | Windows, patio, painters | Modesto · Stanislaus County | — | — |
| Stair Systems | Robert Gregory Jones | — | (209) 595 2204 | GC, remodel, ADU | Riverbank · Stanislaus County | — | — |
| Standard Construction | Standard Construction | info@standardcnst.com | (404) 382-9843 | GC, remodel, ADU | Carlsbad · Stanislaus County | — | — |
| Stanislaus Air Technologies INC | Herrera Lazaro Gutierrez | — | (209) 818 5112 | HVAC | Modesto · Stanislaus County | — | — |
| Stanislaus Construction INC | Rogelio Gonzalez | — | (209) 380 0081 | Other roofers | Empire · Stanislaus County | — | — |
| Stanislaus County's Cal - West Roofing INC | Allen Duane Ford | — | (209) 576 7670 | Other roofers | Modesto · Stanislaus County | — | — |
| Stanislaus Electric Motor Works - Power Tool And Motor (sei) | Stanislaus Electric Motor Works - Power Tool And Motor (sei) | — | (209) 523-0125 | Electricians | Modesto · Stanislaus County | — | — |
| Stanislaus Mechanical INC | Stephen David Owens | — | (209) 850 2606 | GC, remodel, ADU | Ceres · Stanislaus County | — | — |
| Stanislaus Plumbing INC | Alvaro Galvan | — | (209) 537 5704 | Other | Ceres · Stanislaus County | — | — |
| Stanislaus Pool Resurfacing | Stanislaus Pool Resurfacing | — | (209) 249-0847 | Pool | Modesto · Stanislaus County | — | — |
| Stanislaus River Electric INC | Justin Don Norwood | — | (209) 535 6405 | Electricians | Oakdale · Stanislaus County | — | — |
| Stanislaus Roofing | Stanislaus Roofing | admin@stanislausroofing.com | (239) 413-6226 | Other roofers | Modesto · Stanislaus County | — | — |
| Stanislaus Stove & Flue | Stanislaus Stove & Flue | — | (209) 576 1203 | Other | Modesto · Stanislaus County | — | — |
| Stanislaus Tint | Stanislaus Tint | — | (209) 632-9974 | Windows, patio, painters | Turlock · Stanislaus County | — | — |