| Cornerstone Paving Company | Gary Lawrence Golobe | — | (707) 763 3407 | Other | Santa Rosa · Sonoma County | — | — |
| Cornerstone Roofing INC | Lucas Christopher Smith | — | (707) 546 3547 | Other roofers | Sebastopol · Sonoma County | — | — |
| Corona Drywall | Corona Drywall | — | (707) 843 0085 | Other | Santa Rosa · Sonoma County | — | — |
| Corona's Construction INC | Rodriguez Francisco Corona | — | (707) 888 9994 | GC, remodel, ADU | Cotati · Sonoma County | — | — |
| Cort Electric | Gordon S Cort | — | (707) 283 7066 | Electricians | Petaluma · Sonoma County | — | — |
| Cortes Builders INC DBA Cortes Construction | Pedro Jr Cortes | — | (707) 806 2782 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Cortlandt Roofing INC | Cortlandt Todd Iverson | roofing@cortlandtroofing.com | (707) 542 0446 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Coscia Construction Remodel INC | Anthony David Coscia | — | (707) 490 7329 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Cosentino Construction | Alexander Steven Cosentino | — | (707) 738 1641 | GC, remodel, ADU | Bodega · Sonoma County | — | — |
| Costa Construction | Marty Paul Costa | astigma@astigmatic.com | (707) 328 3258 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Cottam Enterprises INC | Robert Garfield Cottam | — | (707) 889 7741 | Other | Sonoma · Sonoma County | — | — |
| Cotter Home Services | Brian Collumcille Cotter | — | (707) 794 1279 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Cottrell Construction | John Richard Cottrell | — | (707) 762 3065 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Counterpoint Construction Services INC | Justin Dale Walling | — | (707) 824 8440 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Country Side Plumbing | Country Side Plumbing | — | (707) 894 2482 | Other | Cloverdale · Sonoma County | — | — |
| Countryside Landscape INC | Juan Bencourt Oseguera | — | (707) 241 6156 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| County Wide Construction & Painting | Christopher Daniel Schooling | — | (707) 975 9916 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Cowans Healdsburg Tree INC | Patricia Ann Cowan | info@cowanshealdsburgtree.com | (707) 433 2827 | Tree | Healdsburg · Sonoma County | — | — |
| Cox Construction | Paul Ronald Cox | — | (707) 889 9601 | Other | Sebastopol · Sonoma County | — | — |
| Cp Global Painting | Cp Global Painting | — | (707) 393 0518 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Craftsman Floor Coverings INC | Michael David O'brien | — | (707) 778 6608 | Other | Petaluma · Sonoma County | — | — |
| Craftsmen Builders | Corey Michael Bassett | — | (707) 337 9376 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Craig A Nordby | Craig A Nordby | — | (707) 526 4500 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Craig Alan Swanton | Craig Alan Swanton | — | (707) 326 1638 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Craig Schlick Construction | Craig T Schlick | — | (707) 479 9334 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Craigie Construction | Scott Harold Craigie | — | (707) 523 4960 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Crame Co | Todd Allen Cramer | — | (707) 849 5160 | GC, remodel, ADU | Guerneville · Sonoma County | — | — |
| Cranadore Construction INC | Cranadore Construction INC | — | (707) 934-8872 | Restoration | Sonoma · Sonoma County | — | — |
| Crandall Construction | Peter Lane Crandall | — | (559) 280 6517 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Crandall Roofing INC | Thomas Vernon Carrell | crandallroofing@aol.com | (707) 586 2500 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Crane Plumbing | Crane Plumbing | — | (707) 338 5549 | Other | Rohnert Park · Sonoma County | — | — |
| Crawford Construction | Darren Jay Crawford | — | (707) 477 3476 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Crawford Property Maintenance | Crawford Property Maintenance | — | (707) 318 7274 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Crawlspace Specialist | Crawlspace Specialist | — | (707) 318 8280 | Other | Rohnert Park · Sonoma County | — | — |
| Creative Carpentry | Creative Carpentry | — | (707) 578 4831 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Creative Environments | Lindsey Marolie North | — | (707) 827 7980 | Windows, patio, painters | Sebastopol · Sonoma County | — | — |
| Creative Millwork And Design INC | Ramiro Rabadan Ortiz | ramiro@creativemillworkdesign.com | (707) 586 6632 | Other | Rohnert Park · Sonoma County | — | — |
| Creative Oak Hardwood Floors | Creative Oak Hardwood Floors | — | (415) 425 1883 | Other | Sonoma · Sonoma County | — | — |
| Creative Roofing Of Northern California | Gabriel Procopio Diaz | roofing@creativeroofing.com | (707) 588 9889 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Creative Window Fashions INC | Duane Michael Vos | — | (707) 588 8500 | Other | Rohnert Park · Sonoma County | — | — |