| Carpet 4 Less INC | Jehad Suleiman Shatnawi | — | (925) 706 0900 | Other | Antioch · Contra Costa County | — | — |
| Carpet Custom Installers | Carpet Custom Installers | — | (925) 778 5053 | Other | Antioch · Contra Costa County | — | — |
| Carpet One Of San Ramon | Gregory Charles Gibbert | — | (925) 837 3716 | Other | San Ramon · Contra Costa County | — | — |
| Carpio Renovations LLC | Carpio Arturo | — | (925) 237 7131 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Carranza Construction INC | Hugo Ivan Carranza | — | (415) 619 9857 | GC, remodel, ADU | Pittsburg · Contra Costa County | — | — |
| Carrasco Construction INC | Frank Olivas Carrasco | — | (925) 446 7489 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Carrasco Flooring INC | Thomas Paul Gregory | — | (925) 752 1860 | Other | Brentwood · Contra Costa County | — | — |
| Carrera Heating & Air INC | Maximo Gabriel Navarro Gutierrez | — | (925) 575 1338 | HVAC | Brentwood · Contra Costa County | — | — |
| Carrera Vallin Plumbing INC | Jose Luis Carvajal Vallin | — | (510) 867 7259 | Other | Rodeo · Contra Costa County | — | — |
| Carrillo's Concrete | Carrillo's Concrete | — | (925) 513 8826 | Other | Brentwood · Contra Costa County | — | — |
| Carter Electrical Solutions | Jon Aron Carter | — | (925) 628 1389 | Electricians | Antioch · Contra Costa County | — | — |
| Carter's Carpet Service INC | Jared Scott Brown | — | (925) 270 3936 | Other | Concord · Contra Costa County | — | — |
| Carter's Electric | Bobby James Carter | — | (415) 756 7444 | Electricians | Pinole · Contra Costa County | — | — |
| Casa Blanca Construction | Armando Jose Rodriguez | interested@domainmarket.com | (650) 444 2066 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Casale Construction | Christopher James Casale | — | (925) 718 5391 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Casale Custom Builder | Casale Custom Builder | — | (925) 389 9111 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Cascadian Pool Service LLC | Clayton Roscoe Perdue | — | (925) 917 4085 | Pool | Pleasant Hill · Contra Costa County | — | — |
| Casey Paik | Casey Paik | — | (925) 407 7168 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Caspian C Drywall Construction | Orkhan Huseynov | — | (415) 867 6809 | Other | Concord · Contra Costa County | — | — |
| Caspian Electrotech INC | Mahdi Dadkhahshirmahaleh | — | (925) 243 5830 | Electricians | San Ramon · Contra Costa County | — | — |
| Castaneda Iron Works | Castaneda Iron Works | — | (510) 234 4734 | Other | Rodeo · Contra Costa County | — | — |
| Castaneda Roofing & Construction INC | Manuel Salvador Castaneda | — | (925) 664 7988 | Other roofers | Bay Point · Contra Costa County | — | — |
| Castillo Alarm And Electric Systems | Brian James Castillo | — | (925) 565 0837 | Electricians | Oakley · Contra Costa County | — | — |
| Castillo Bros | Castillo Bros | — | (415) 810 4477 | Other | Antioch · Contra Costa County | — | — |
| Castillo Electric | Cristian Estuardo Castillo Monterroso | interested@domainmarket.com | (510) 491 6362 | Electricians | Antioch · Contra Costa County | — | — |
| Castillo General Remodel | Castillo General Remodel | info@castillogeneralremodel.com | (925) 330 2327 | GC, remodel, ADU | Pittsburg · Contra Costa County | — | — |
| Castle Home Inspections | Castle Home Inspections | thecastleinspection@gmail.com | (209) 304-8206 | Inspectors | Ione · Contra Costa County | — | — |
| Castle Management Company INC | Castle Management Company INC | bstarczewski@castlecompanies.com | (925) 328-1240 | Property managers | San Ramon · Contra Costa County | — | — |
| Castle Tile | Castle Tile | kimmara@castletile.com | (925) 382 6873 | Other | Oakley · Contra Costa County | — | — |
| Castle West Construction INC | Louis Randolph Baldacci | — | (925) 328 1000 | GC, remodel, ADU | San Ramon · Contra Costa County | — | — |
| Castro Plumbing | Castro Plumbing | — | (925) 451 8958 | Other | Brentwood · Contra Costa County | — | — |
| Catalano Builder | Catalano Builder | nathanielcatalano@gmail.com | (510) 334 8692 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Catalogs Decor LLC | Ofer Bouskila | — | (925) 522 9641 | Other | Brentwood · Contra Costa County | — | — |
| Catoire Construction | Brian Edward Catoire | — | (925) 382 6798 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Cattarusa Builders | Cattarusa Builders | — | (925) 212 7955 | GC, remodel, ADU | Orinda · Contra Costa County | — | — |
| Cauich Drywall | Cauich Drywall | luiscauich93@gmail.com | (510) 776 1767 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Cavanaugh Construction | John Philip Cavanaugh | — | (925) 639 4764 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Caw Air Construction INC | Liqing Xu | — | (510) 328 5777 | HVAC | Danville · Contra Costa County | — | — |
| Cbc General Contractors INC | Christopher Troy Begg | — | (510) 915 5453 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Cc N Company INC | John Fay Tse | — | (925) 818 4923 | GC, remodel, ADU | Orinda · Contra Costa County | — | — |