| Christopherson Builders LLC | Amy Ann Christopherson Bolten | info@christophersonbuilders.com | (707) 584 6377 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Cinecor Construction LLC | Kelly Clark Corkill | — | (707) 782 8253 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Circuit Rider Community Services | Algeo Che Casul | — | (707) 838 6641 | Windows, patio, painters | Windsor · Sonoma County | — | — |
| Cirelli Construction INC | Cirelli Giorgio | gcirelli@cirelliconstruction.com | (707) 338 8278 | GC, remodel, ADU | Cotati · Sonoma County | — | — |
| City Builder | City Builder | — | (415) 596 5871 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Civic Proud Enterprises INC | Joseph Kevin Jr Jones | — | (707) 571 8911 | Other | Petaluma · Sonoma County | — | — |
| Civil Electrical Construction INC | Benjamin Harley Ford | — | (707) 322 5446 | Electricians | Petaluma · Sonoma County | — | — |
| Claremont Pools INC | Mark Richard Navickas | info@claremontpools.com | (925) 505 8512 | Pool | Cloverdale · Sonoma County | — | — |
| Clark Construction | Robert Gray Clark | — | (707) 696 0600 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Clark Electrical Contractors INC | Bradley Joseph Clark | — | (707) 433 9036 | Electricians | Healdsburg · Sonoma County | — | — |
| Clark Innovative General Construction Contractor | Christopher Michael Clark | — | (707) 860 6640 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Clark Pest Control | Clark Pest Control | — | (707) 205-4223 | Pest, tile roofs | Santa Rosa · Sonoma County | — | — |
| Classic Construction | Michael Carl Caldwell | — | (707) 796 3672 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| Classic Mill & Cabinet | Michael Brian Siemsen | — | (707) 894 9800 | Other | Cloverdale · Sonoma County | — | — |
| Classic Tile | Bradford Nelson Wells | sales@classictile.com | (707) 763 5278 | Other | Petaluma · Sonoma County | — | — |
| Clay Teevan Painting | Clay Teevan Painting | — | (707) 486 0667 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Cle Excavation General Engineering | Cle Excavation General Engineering | — | (707) 974 1442 | Other | Santa Rosa · Sonoma County | — | — |
| Clean - Cut Builder Corp | Juan Carlos Velazquez Rangel | — | (415) 524 5723 | GC, remodel, ADU | Cotati · Sonoma County | — | — |
| Clean Cut Builders | Clean Cut Builders | — | (415) 279 3414 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Clean Cut Drywall | Clean Cut Drywall | — | (209) 985 0655 | Other | Santa Rosa · Sonoma County | — | — |
| Clean-rite Chimney Sweep | Clean-rite Chimney Sweep | — | (707) 291 2075 | Other | Santa Rosa · Sonoma County | — | — |
| Clear Heart Drilling INC | Rejina M Pearson | amber@clearheartdrilling.com | (707) 484 1506 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Clear Telecommunications LLC | Eric Harm Oncken | — | (707) 858-5580 | Other | Santa Rosa · Sonoma County | — | — |
| Clear Wood Plumbing | Jakob Earl Boisclair | — | (707) 480 6028 | Other | Sebastopol · Sonoma County | — | — |
| Clearline Plumbing | Clearline Plumbing | clearline1985@gmail.com | (707) 322 3540 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Clearview Construction INC | Michael Patrick Melanephy | — | (415) 328 4887 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Clearview Electric LLC | Steven Kenneth Krause | — | (415) 717 2734 | Electricians | Santa Rosa · Sonoma County | — | — |
| Clemmer Construction Co INC | Thomas James Clemmer | tomclemmercc@gmail.com | (707) 694 9479 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Cleveland Construction & Environmental Services | Scott Mason Cleveland | — | (707) 331 9607 | GC, remodel, ADU | Cloverdale · Sonoma County | — | — |
| Climate Services Heating And Air Conditioning | Sean Paul Perez | — | (707) 396 0181 | HVAC | Santa Rosa · Sonoma County | — | — |
| Cline Landscapes & Maintenance Services INC | Michael Jon Cline | — | (707) 935 0900 | Windows, patio, painters | El Verano · Sonoma County | — | — |
| Clinton Brian Garrick | Clinton Brian Garrick | — | (707) 570 7222 | Other | Santa Rosa · Sonoma County | — | — |
| Cloverdale Plumbing Heating And Air Conditioning | Richard A Rauch | — | (707) 894 2120 | HVAC | Cloverdale · Sonoma County | — | — |
| Cloverdale Ukiah Roofing | Edward Hilario Robles | — | (707) 272 8094 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Cm Tile Design LLC | Carlos J Mendoza | — | (415) 246 8089 | Other | Petaluma · Sonoma County | — | — |
| Cmc Remodeling INC | Carl Maynard Colgrove | — | (707) 974 7318 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Cmc Window Films | Cmc Window Films | info@cmcwindowfilms.com | (707) 486 1641 | Other | Santa Rosa · Sonoma County | — | — |
| Cntrline Plumbing Service INC | Cody Joseph Aaron Lehman | — | (707) 308 5599 | Other | Rohnert Park · Sonoma County | — | — |
| Coast Electric Solutions | Dodd Toby | — | (707) 529 4857 | Electricians | Occidental · Sonoma County | — | — |
| Coast Integration Media & Communications | Coast Integration Media & Communications | — | (707) 775 8524 | Other | Forestville · Sonoma County | — | — |