| W C Ferrell Cabinetry | W C Ferrell Cabinetry | — | (707) 528 4370 | Other | Santa Rosa · Sonoma County | — | — |
| W Custom Builders | W Custom Builders | — | (707) 481 6376 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| W Isaak Construction INC DBA California Builders | William Georg Isaak | — | (707) 782 9002 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| W J Ryan | W J Ryan | — | (707) 539 1924 | Other | Santa Rosa · Sonoma County | — | — |
| W K Mc Lellan Co | Rita Therese Lacy | — | (707) 763 2407 | Other | Petaluma · Sonoma County | — | — |
| W M Linn Company | William Mark Linn | — | (707) 894 8689 | Electricians | Cloverdale · Sonoma County | — | — |
| W M W Construction | William Mark Wilson | info@wmwconstruction.com | (707) 695 2804 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| W Scott Miller Construction INC | Walter Scott Miller | — | (707) 829 8429 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Wagner Carpet Laying Co | Margaret Teresa Wagner | — | (707) 542 5700 | Other | Santa Rosa · Sonoma County | — | — |
| Wagner Custom Millwork INC | Christian John Wagner | — | (908) 528 7429 | Other | Petaluma · Sonoma County | — | — |
| Wahl Plumbing INC | Joseph Edward Wahl | — | (707) 529 8785 | Other | Windsor · Sonoma County | — | — |
| Walden & Co | Neal Leroy Walden | — | (707) 431 2640 | Other | Healdsburg · Sonoma County | — | — |
| Waldron Landscaping INC | Luis Gerardo Hernandez | walplant@vom.com | (707) 732-4021 | Windows, patio, painters | Sonoma · Sonoma County | — | — |
| Walker & Associates INC | Ryan Alan Walker | — | (707) 322 4002 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Walker Construction | Robert Steven Walker | — | (707) 479 5505 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Walker Construction | Bryan Allen Walker | — | (707) 478 9883 | GC, remodel, ADU | Cazadero · Sonoma County | — | — |
| Wallpaper Perfection INC | Anthony Edward Boynton | info@latinotype.com | (717) 703 6428 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Walls Painting | Walls Painting | info@wallspainting.com | (438) 940-4955 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Wallstrum Building | Wallstrum Building | — | (707) 577 0459 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Walsh Plumbing & Mechanical | Walsh Plumbing & Mechanical | — | (707) 477 1732 | Other | Santa Rosa · Sonoma County | — | — |
| Walter Schnepper Construction | Walter Craig Schnepper | — | (707) 849 4295 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Walters Construction INC | Justin Talmadge Walters | — | (707) 236 5137 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Walters Custom Cabinetry | Walters Custom Cabinetry | — | (707) 980 0078 | Other | Sebastopol · Sonoma County | — | — |
| Ward Rhobe Management Corporation | Richard Alan Valenza | — | (818) 692 2000 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Wards Tile Works | Wards Tile Works | — | (707) 292 0137 | Other | Windsor · Sonoma County | — | — |
| Wargo Construction INC | John Arthur Wargo | — | (707) 312 0245 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Warm Zone INC | Joseph Gary Gossens | — | (707) 823 9322 | HVAC | Sebastopol · Sonoma County | — | — |
| Warming Trends INC | Eric Charles Miller | — | (707) 578 9276 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Warne Construction INC | Stanley Carl Warne | — | (707) 480 5380 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Warner Electric Incorporated | Stephen Charles Jr Warner | — | (707) 583 3598 | Electricians | Santa Rosa · Sonoma County | — | — |
| Warner Landscape Construction | Justin Todd Warner | — | (707) 307 9550 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Warren Construction & Roofing INC | Mark Christopher Warren | — | (707) 578 2088 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Washed In Paint | Washed In Paint | — | (707) 210 5325 | Windows, patio, painters | Boyes Hot Springs · Sonoma County | — | — |
| Water And Mold Remediation | Water And Mold Remediation | — | (707) 413 5958 | Other | Santa Rosa · Sonoma County | — | — |
| Water Squared | Water Squared | — | (707) 477 2867 | Other | Santa Rosa · Sonoma County | — | — |
| Waterwise Land Design | Waterwise Land Design | waterwise.landdesign@gmail.com | (831) 277 6826 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Waterworks Industries Incorporated | Toupin Mathais | — | (707) 837 7900 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Waterworks Industries LLC | Ralph Millard Holden | — | (707) 837 7900 | HVAC | Windsor · Sonoma County | — | — |
| Watts Up Electric | Jorge Mauricio Alfaro | — | (707) 509 9699 | Electricians | Sonoma · Sonoma County | — | — |
| Waugh Construction | Daniel John Waugh | — | (707) 799 7694 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |