| Crowne Landscape INC | Dennis James Orgoglio | — | (925) 240 4442 | Windows, patio, painters | Discovery Bay · Contra Costa County | — | — |
| Crowworks | Carl Rene Deskins | — | (510) 520 7989 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Cruz Con Corp | Remigio Villano Cruz | — | (510) 407 2850 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Cruz Electrical | Manuel Alberto Cruz Rivas | — | (916) 738 1359 | Electricians | Richmond · Contra Costa County | — | — |
| Crystal's Flooring | Crystal's Flooring | — | (925) 577 2848 | Other | Oakley · Contra Costa County | — | — |
| Csb Plumbing | Csb Plumbing | — | (925) 698 9436 | Other | San Ramon · Contra Costa County | — | — |
| Ct Electric LLC | Chris Trummell | — | (415) 819 7660 | Electricians | El Sobrante · Contra Costa County | — | — |
| Cti - Controltech INC | George Perry Constas | — | (925) 208 4250 | Other | San Ramon · Contra Costa County | — | — |
| Ctm Builders INC | Charles Timothy Mc Innis | — | (925) 817 0306 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Cuatro Amigos INC DBA A J Bono Plumbing | Maria Theresa De La Cruz Perez | — | (925) 676 1080 | Other | Concord · Contra Costa County | — | — |
| Cuescon | Patrick V Cuesta | — | (925) 408 4736 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Cuevas Floors | Cuevas Floors | — | (925) 565 1481 | Other | Concord · Contra Costa County | — | — |
| Cuevas Tile & Marble | Cuevas Tile & Marble | — | (925) 382 3638 | Other | Concord · Contra Costa County | — | — |
| Culverhouse Construction | Steven Ralph Culverhouse | info@culverhouseconstruction.com | (510) 685 3057 | GC, remodel, ADU | Rodeo · Contra Costa County | — | — |
| Cunha Pavers INC | Leandro Messias Da Cunha | — | (510) 804 9516 | Other | Richmond · Contra Costa County | — | — |
| Cunningham Construction | Paul Eugene Cunningham | info@cunninghamconstruction.com | (925) 326 5420 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Curb Appeal Landscape LLC | Martine Ledezma Lopez | — | (925) 685 8030 | Windows, patio, painters | Clayton · Contra Costa County | — | — |
| Curiel Construction INC | Curiel Gabriel | — | (925) 237 7038 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Curiel Landscape INC | Jose Donaciano Reynoso | — | (925) 227 7827 | Windows, patio, painters | Oakley · Contra Costa County | — | — |
| Curley Construction | Joseph Alan Curley | — | (925) 407 6046 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Curran Electric | Patrick Fidelis Curran | — | (916) 896 2813 | Electricians | Martinez · Contra Costa County | — | — |
| Current Electric & Lighting INC | Robin Gilbert Trunnell | — | (925) 689 9185 | Electricians | Concord · Contra Costa County | — | — |
| Curt Haisley Construction | Curtis John Haisley | — | (925) 216 4765 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Curt Riess Construction | William Curt Riess | — | (925) 202 4005 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Custom Car Alarms | Custom Car Alarms | — | (925) 680-8881 | Alarm and generators | Pleasant Hill · Contra Costa County | — | — |
| Custom Home Integrators | Custom Home Integrators | — | (510) 504 2949 | Other | Pleasant Hill · Contra Costa County | — | — |
| Custom Home Interiors INC | Marquez Armando | customhomeinterior@gmail.com | (510) 758 5195 | GC, remodel, ADU | Pinole · Contra Costa County | — | — |
| Custom Modular Structures | Custom Modular Structures | — | (925) 413 8041 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |
| Custom Remodel | Custom Remodel | customhomeremodeling@yahoo.com | (925) 890 7973 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Custom Roofing & Gutters | Peter Robert Flores | — | (925) 628 5587 | Other roofers | Antioch · Contra Costa County | — | — |
| Custom Woodworks | Custom Woodworks | interested@domainmarket.com | (415) 948 1341 | Other | Pittsburg · Contra Costa County | — | — |
| Cutting Edge Construction Unlimited | Frederick Louis David Jr Clairmonte | — | (925) 628 0409 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Cutting Edge Tile And Stone | Cutting Edge Tile And Stone | — | (925) 382 2577 | Other | Brentwood · Contra Costa County | — | — |
| Cv Floors LLC | Steven Paul Woerner | — | (925) 672 2597 | Other | Clayton · Contra Costa County | — | — |
| Cvm Painting INC | Arturo Melquisedec Villanueva Moreno | info@cvmpainting.com | (510) 417 6845 | Windows, patio, painters | El Sobrante · Contra Costa County | — | — |
| Cxc Construction | Chinh X Cao | — | (925) 665 4321 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Cypress General Contractor INC | Jorge Luis Quintero Jr Palafox | — | (510) 734 4073 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Cypress Landscape | Steven Sanchez | — | (925) 978 7363 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| D & D & Sons INC | David George Stewart | — | (510) 235 0055 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| D & D Construction Co | Konstantinos Dimitrios Makris | — | (415) 601 6907 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |