| C K Water Systems & Landscape Development | Alexander Colin Cartwright | — | (925) 395 3103 | Windows, patio, painters | San Rafael · Marin County | — | — |
| C Medina Plumbing | C Medina Plumbing | — | (415) 455 8285 | Other | Fairfax · Marin County | — | — |
| C P Sheet Metal A Partnership | Michael Paul Pedroni | — | (415) 453 1306 | HVAC | San Rafael · Marin County | — | — |
| C R Construction-excavation | Cory Robert Steege | — | (415) 456 7432 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| C S S Environmental Services INC | Aaron Neil Stessman | — | (415) 883 6203 | Other | Novato · Marin County | — | — |
| C T Construction | Charles James Taylor | — | (415) 870 6284 | GC, remodel, ADU | Ross · Marin County | — | — |
| C T Innovative Builders INC | Tapia Charli Zoto | — | (415) 328 5319 | GC, remodel, ADU | Novato · Marin County | — | — |
| C W S Construction Group INC | Charlie Winslow Slack | — | (415) 599 6545 | GC, remodel, ADU | Novato · Marin County | — | — |
| C.l.d Painting | C.l.d Painting | — | (415) 559 0953 | Windows, patio, painters | San Rafael · Marin County | — | — |
| C3 Design Build & Cabinetry INC | Chadwick Walden Chastain | — | (415) 990 2964 | Electricians | Novato · Marin County | — | — |
| Cactus Metal Design INC | Maria Elena Sanchez | cmdesign01@yahoo.com | (415) 845 7978 | Other | Novato · Marin County | — | — |
| Caffrey Landscapes INC | Darragh Peter Caffrey | caffreylandscapes@gmail.com | (415) 279 8469 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Cal Summit Builders | Noel Rodrigo Barajas | noel@calsummitbuilders.com | (510) 685 5951 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Calderon Concrete Contractors INC | Byron Rolando Calderon Cifuentes | — | (415) 482 7615 | Other | San Rafael · Marin County | — | — |
| Calderon Excavations INC | Emerson Josue Calderon Piedrasanta | — | (415) 261 0538 | Other | Greenbrae · Marin County | — | — |
| Calderon Painting & Decorating | Calderon Painting & Decorating | — | (415) 261 5456 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Cali - Concepts | Brendan Patrick Burke | — | (704) 902 5643 | GC, remodel, ADU | Woodacre · Marin County | — | — |
| California Fencing | California Fencing | — | (415) 472 1419 | Windows, patio, painters | San Rafael · Marin County | — | — |
| California Rebar Fabricators Incorporated | Michelle Ann Whiteside | — | (510) 439 4206 | GC, remodel, ADU | Novato · Marin County | — | — |
| California Space Organizers INC | Vasilis Andreas Fourakis | — | (415) 454 7477 | Other | San Rafael · Marin County | — | — |
| Calmell Builders LLC | Juan Carlos Jr Calmell | — | (415) 497 6193 | GC, remodel, ADU | Lagunitas · Marin County | — | — |
| Cam Services | Cam Rodney Doerschler | info@camservices.com | (415) 927 0433 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Camacho's Construction | Camacho Herrera Jose | — | (415) 652 1871 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Cameron Lontz | Cameron Lontz | — | (415) 531 4296 | GC, remodel, ADU | Novato · Marin County | — | — |
| Cameron Tile & Stone INC | Troy Wayne Cameron | — | (415) 883 5400 | Other | Novato · Marin County | — | — |
| Canche Construction INC | Stephen Henry Litke | — | (415) 290 2302 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Candle Electrical Co INC | Juan Neftali Gomez Mejia | — | (415) 798 6106 | Electricians | Novato · Marin County | — | — |
| Canterbury Tiles | Canterbury Tiles | — | (415) 531 0912 | Other | Mill Valley · Marin County | — | — |
| Capripools Services INC | Walter Lisardo Mazariegos | — | (415) 246 7273 | Pool | Novato · Marin County | — | — |
| Caputo Construction | Adriano Mauro Caputo | info@caputoconstruction.com | (415) 747 6749 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Carey R Olsen Construction | Carey Roy Olsen | — | (415) 897 2011 | GC, remodel, ADU | Novato · Marin County | — | — |
| Carl J Augusto Plumbing | Carl J Augusto Plumbing | — | (415) 897 0773 | Other | Novato · Marin County | — | — |
| Carlos A A Construction INC | Juan Carlos Arriaga Alvarez | — | (415) 320 2791 | GC, remodel, ADU | Novato · Marin County | — | — |
| Caron Climate Control | Caron Climate Control | mlc@caronclimatecontrol.com | (415) 453 9323 | HVAC | San Rafael · Marin County | — | — |
| Carrera Marble Company | Korn Frank | info@carrera-marble.com | (415) 454 4647 | Other | San Rafael · Marin County | — | — |
| Carreras Electric | Robert Daniel Carreras | — | (415) 717 3251 | Electricians | Mill Valley · Marin County | — | — |
| Carrillo's Construction | Carlos Enrique Carrillo Y Carrillo | — | (415) 225 2369 | GC, remodel, ADU | Novato · Marin County | — | — |
| Carter Construction Consultation | Franklin Steph Carter | — | (415) 314 6924 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Carter Yates Construction | Carter Jonas Yates | — | (415) 559 2275 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| Cartwright Construction | Donovan Frederick Iii Cartwright | — | (415) 302 5856 | GC, remodel, ADU | Novato · Marin County | — | — |