| Shieler Construction INC | Aaron Frank Shieler | — | (209) 200 6621 | GC, remodel, ADU | Acampo · San Joaquin County | — | — |
| Shine Land Landscape | Cuong Van Vo | — | (209) 401 1304 | Windows, patio, painters | Stockton · San Joaquin County | — | — |
| Shipman Security | Shipman Security | — | (442) 333-9408 | Alarm and generators | Carlsbad · San Joaquin County | — | — |
| Shutter City | Robert Richard Calderara | — | (209) 599 2006 | Other | Ripon · San Joaquin County | — | — |
| Sid Landis Flooring | Sid Landis Flooring | — | (209) 642 9099 | Other | Woodbridge · San Joaquin County | — | — |
| Sierra Cabinet And Millwork INC | Jerry De Hoge | — | (209) 941 4002 | Other | Stockton · San Joaquin County | — | — |
| Sierra Construction & Septic | Jose Luis Ulloa | — | (209) 298 3069 | GC, remodel, ADU | Tracy · San Joaquin County | — | — |
| Sierra Crest Builders INC | Rogelio Jr Rosales | — | (209) 918 6214 | GC, remodel, ADU | Woodbridge · San Joaquin County | — | — |
| Sierra Home Painting & Decor | Sierra Home Painting & Decor | — | (510) 677 6927 | Windows, patio, painters | Tracy · San Joaquin County | — | — |
| Sierra Play Partners | Loren Ward Jessop | astigma@astigmatic.com | (209) 541 9658 | Windows, patio, painters | Ripon · San Joaquin County | — | — |
| Sierra Services | Billy Wayne Martin | — | (209) 649 4453 | GC, remodel, ADU | Stockton · San Joaquin County | — | — |
| Sierra Sprinkler Services INC | George Thomas Sattler | — | (209) 368 5200 | Other | Acampo · San Joaquin County | — | — |
| Sign Art Factory | Sign Art Factory | — | (714) 931 5200 | Other | Woodbridge · San Joaquin County | — | — |
| Signco | Shirley Katherine Dyson | info@signco.com | (209) 464 8577 | Other | Stockton · San Joaquin County | — | — |
| Siltstone Construction INC | Nelson Amilcar Juarez | — | (650) 754 3480 | GC, remodel, ADU | Lathrop · San Joaquin County | — | — |
| Silva's Steel Structures INC | Lawrence Henry Silva | — | (209) 483 6729 | Other | Manteca · San Joaquin County | — | — |
| Silveira's Plumbing Company | Jaime Manuel Ii Silveira | — | (209) 816 3780 | Other | Stockton · San Joaquin County | — | — |
| Silver Custom Stairs & Finish Carpentry | Francisco Javier Plata Guerrero | — | (209) 214 4958 | Other | Ripon · San Joaquin County | — | — |
| Silver Stone Roofing LLC | Escobar Cortez Delfino | — | (209) 817 7129 | Other roofers | Stockton · San Joaquin County | — | — |
| Silvestre Wallcovering Painting | Silvestre Wallcovering Painting | — | (925) 918 7399 | Windows, patio, painters | Stockton · San Joaquin County | — | — |
| Silvestre's Mechanical Company INC | Silvestre V Hernandez | — | (916) 869 7819 | HVAC | Lodi · San Joaquin County | — | — |
| Simi Heating & Air INC | Anthony Michael Simi | — | (209) 321 2001 | HVAC | Stockton · San Joaquin County | — | — |
| Simon And Son's Painting | Simon And Son's Painting | — | (510) 867 1442 | Windows, patio, painters | Stockton · San Joaquin County | — | — |
| Simple - Tech Construction | Juan Manuel Mejia | — | (209) 401 5544 | GC, remodel, ADU | Manteca · San Joaquin County | — | — |
| Simplified Integrations INC | Jason Alan Porter | — | (877) 711 1617 | Electricians | Tracy · San Joaquin County | — | — |
| Simpson Construction Company | Paul Russ Simpson | — | (209) 815 1170 | GC, remodel, ADU | Tracy · San Joaquin County | — | — |
| Simpson Construction Works | Jeffrey David Simpson | — | (209) 329 9168 | GC, remodel, ADU | Lodi · San Joaquin County | — | — |
| Simpson Plumbing | Simpson Plumbing | — | (209) 229 4749 | Other | Tracy · San Joaquin County | — | — |
| Singh Air-conditioning And Heating | Singh Air-conditioning And Heating | — | (209) 814 6492 | HVAC | Ripon · San Joaquin County | — | — |
| Single Line Electric INC | Sanchez Nery | — | (925) 922 2617 | Electricians | Lathrop · San Joaquin County | — | — |
| Sinor Integrated Systems | Sinor Integrated Systems | — | (209) 479 2568 | Other | Stockton · San Joaquin County | — | — |
| Sisley INC | John Lester Sisley | — | (209) 607 7127 | Other | Stockton · San Joaquin County | — | — |
| Sissell Plumbing LLC | Vance Lee Reasor | contact@sissellplumbing.com | (209) 835 1519 | Other | Tracy · San Joaquin County | — | — |
| Six Framing Construction | Villa Javier | — | (209) 688 5219 | Other | Stockton · San Joaquin County | — | — |
| Sj Flooring LLC | Raul Rodriguez | — | (408) 509 6318 | Other | Stockton · San Joaquin County | — | — |
| Sjvc Antelope Valley | Sjvc Antelope Valley | — | (661) 974-8282 | HVAC | Lancaster · San Joaquin County | — | — |
| Sjvc Ontario | Sjvc Ontario | — | (909) 948-7582 | HVAC | Ontario · San Joaquin County | — | — |
| Sjvc Temecula | Sjvc Temecula | — | (951) 296-6015 | HVAC | Temecula · San Joaquin County | — | — |
| Ska-bike Painting | Cervantes Ivan Zuniga | — | (209) 601 0170 | Windows, patio, painters | Stockton · San Joaquin County | — | — |
| Skipy Hand Grading | Skipy Hand Grading | — | (209) 483 0142 | Other | Lodi · San Joaquin County | — | — |