| Cal Tile | Cal Tile | — | (707) 290 9293 | Other | Santa Rosa · Sonoma County | — | — |
| Calahan Custom Building | Calahan Custom Building | — | (707) 892 1662 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Caldera | Gary Brian Caldera | — | (707) 372 8886 | Other | Santa Rosa · Sonoma County | — | — |
| Caldwell / Trouette Gen Contractors INC | Casey Joseph Caldwell | — | (707) 433 8425 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Caldwell Builders | Caldwell Builders | — | (707) 217 1456 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Caldwell Construction | Casey Paul Caldwell | sean@caldwellconstruction.com | (805) 845-7555 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Caldwell Construction Co Healdsburg | Casey Joseph Caldwell | — | (707) 433 8425 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Caldwell Duncan Projects | David Wayne Duncan | — | (707) 542 1249 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Caleb White Construction | Caleb Richmond White | — | (707) 400 3749 | GC, remodel, ADU | Forestville · Sonoma County | — | — |
| Cali Fire Protection LLC | Carlos Alfredo Figueroa | — | (707) 888 5251 | Other | Santa Rosa · Sonoma County | — | — |
| Caliburn Design & Construction | Glenn William Tryon | — | (707) 696 1106 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| California Custom Electrical Contractors | Jason Robert Kuboshige | — | (707) 766 6071 | Electricians | Petaluma · Sonoma County | — | — |
| California Custom Tinting INC | James Arthur Mills | — | (707) 781 9212 | Other | Petaluma · Sonoma County | — | — |
| California Heating & Air Conditioning | California Heating & Air Conditioning | — | (707) 546 1811 | HVAC | Santa Rosa · Sonoma County | — | — |
| California Knight | California Knight | — | (707) 291 6528 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| California Painting | California Painting | — | (707) 721 5682 | Windows, patio, painters | Boyes Hot Springs · Sonoma County | — | — |
| California Preservation Valley Builders | California Preservation Valley Builders | — | (707) 815 1005 | GC, remodel, ADU | Glen Ellen · Sonoma County | — | — |
| California Professional Tree Service | Jesus Diaz Barrera | — | (707) 228 7891 | Tree | Santa Rosa · Sonoma County | — | — |
| California Property Improvement | California Property Improvement | — | (707) 494 9814 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| California Screen Machine | California Screen Machine | astigma@astigmatic.com | (707) 328-1927 | Windows, patio, painters | Sonoma · Sonoma County | — | — |
| California State Insulation & General Contractor | Beltran Alvaro | — | (707) 546 3177 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| California's Custom Cabinetry | California's Custom Cabinetry | — | (707) 765 9144 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Callahan Landscape Contractors INC | Christopher Riley Callahan | — | (707) 595 8799 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Calleja Paint Co | Matthew Mark Calleja | — | (707) 938 5712 | Windows, patio, painters | Sonoma · Sonoma County | — | — |
| Callinan Construction | Gary Patrick Callinan | — | (707) 318 2007 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Calmex Construction | Guerrero Fernando | — | (415) 798 0650 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Calnorthex Concrete | Calnorthex Concrete | — | (707) 490 7975 | Other | Santa Rosa · Sonoma County | — | — |
| Calstroy | Safonau Andrei | — | (415) 250 3215 | Electricians | Guerneville · Sonoma County | — | — |
| Calvi Construction INC | Richard Raymond Calvi | roncalvi@gmail.com | (707) 874 3483 | Other | Occidental · Sonoma County | — | — |
| Calvin Cutler Construction | Calvin Joseph Cutler | — | (707) 205 9631 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Camara Construction INC | Jose Valentin Camara Aban | jose@camaraconstruction.com | (707) 623 0324 | GC, remodel, ADU | Forestville · Sonoma County | — | — |
| Cambra Contracting INC | Jason Manuel Cambra | — | (707) 239 8152 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Camco Construction INC | Clifford Vincent Dufresne | — | (707) 396 6599 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Camelot Painting Service | Mark Edward Plourde | — | (707) 478 9933 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Cameron's Custom Electric LLC | Cameron Thayne Varney | — | (415) 261 5303 | Electricians | Petaluma · Sonoma County | — | — |
| Camilli Tile | Camilli Tile | — | (707) 540 5431 | Other | Santa Rosa · Sonoma County | — | — |
| Campbell Electric | Richard Lynn Campbell | — | (707) 478 6462 | Electricians | Santa Rosa · Sonoma County | — | — |
| Campi Development INC | Nicholas James Campi | — | (650) 245 9510 | GC, remodel, ADU | Kenwood · Sonoma County | — | — |
| Campos Landscaping INC | Reynaldo Jr Robledo Campos | anapbm@gmail.com | (707) 913 8015 | Windows, patio, painters | Sonoma · Sonoma County | — | — |
| Campos Plumbing INC | Jose Casias Campos | — | (707) 480 5666 | Other | Santa Rosa · Sonoma County | — | — |