| Classic Innovation | Classic Innovation | — | (408) 340 0826 | Other | Belmont · San Mateo County | — | — |
| Classic Painting Company | Juan Alirio Jimenez | interested@domainmarket.com | (415) 722 3907 | Windows, patio, painters | Daly City · San Mateo County | — | — |
| Clean Energy Renewables INC | Jonathan Joseph Rincon | mattjr@clean-energy-renewables.com | (650) 906 7626 | Electricians | Redwood City · San Mateo County | — | — |
| Clean Finish Painting | Clean Finish Painting | estimate.cleanfinishpainting@gmail.com | (650) 207 7656 | Windows, patio, painters | San Carlos · San Mateo County | — | — |
| Clean Pipes Plumbing | Clean Pipes Plumbing | — | (650) 868 0131 | Other | Redwood City · San Mateo County | — | — |
| Clean Solution Services INC | Jose Baltazar Echeverria | — | (415) 794 6884 | GC, remodel, ADU | Daly City · San Mateo County | — | — |
| Clearstead Construction LLC | Sean Joseph Smith | — | (415) 722 9407 | GC, remodel, ADU | San Bruno · San Mateo County | — | — |
| Clearstone Chimney Inspections San Mateo | Clearstone Chimney Inspections San Mateo | — | (650) 240-4284 | Inspectors | San Mateo · San Mateo County | — | — |
| Cleary Av | Cleary Av | — | (650) 218 1194 | Other | San Mateo · San Mateo County | — | — |
| Clever Plumbing & Rooter INC | Angel Leonel Marroquin Chavaque | — | (650) 834 0821 | Other | San Bruno · San Mateo County | — | — |
| Clic LLC | Michael Alan Hicks | — | (415) 421 2900 | Other | Burlingame · San Mateo County | — | — |
| Cliff Roepke | Cliff Roepke | — | (650) 697 7081 | Other | Burlingame · San Mateo County | — | — |
| Clix Systems | Clix Systems | — | (650) 759 8778 | Electricians | Hillsborough · San Mateo County | — | — |
| Clog Buster Plumbing INC | Joseph Mitchell Bustos Manuel | — | (650) 740 1264 | Other | Daly City · San Mateo County | — | — |
| Clohessy Michael Construction Co | Michael Anthony Clohessy | — | (650) 222 4623 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| Closet Factory | Rosenberg Uri | — | (650) 595 9999 | Other | San Carlos · San Mateo County | — | — |
| Coast Builders INC | Farshad Askari | — | (650) 455 8885 | GC, remodel, ADU | Half Moon Bay · San Mateo County | — | — |
| Coast House Movers | Martin Anthony Petersen | — | (650) 359 0921 | GC, remodel, ADU | Pacifica · San Mateo County | — | — |
| Coast To Coast Development INC | Aurelio Scott Peccei | — | (650) 654 6412 | GC, remodel, ADU | San Carlos · San Mateo County | — | — |
| Coastal Roots Garden Design | Coastal Roots Garden Design | — | (650) 740 7286 | Windows, patio, painters | Half Moon Bay · San Mateo County | — | — |
| Coastal Waterworks | Coastal Waterworks | — | (650) 771 7510 | Other | La Honda · San Mateo County | — | — |
| Coastline Construction INC | Robert Joseph Avila | — | (650) 245 8753 | Electricians | Half Moon Bay · San Mateo County | — | — |
| Coastline Electrical INC | Robert Joseph Avila | — | (650) 245 8753 | Electricians | Half Moon Bay · San Mateo County | — | — |
| Coastline Grading & Underground | Coastline Grading & Underground | — | (650) 554 1718 | Other | Pacifica · San Mateo County | — | — |
| Coastside Appliance Repair And Heating | Coastside Appliance Repair And Heating | — | (650) 576 2326 | HVAC | Half Moon Bay · San Mateo County | — | — |
| Coastside Clean Energy | Marcelo Nunes Macedo | — | (415) 501 0540 | Electricians | Pacifica · San Mateo County | — | — |
| Coastside Construction INC | Garcia Manuel Castro | — | (650) 218 1810 | GC, remodel, ADU | Montara · San Mateo County | — | — |
| Coastside Excavation INC | Brendan Henry Power | — | (650) 302 0261 | Other | El Granada · San Mateo County | — | — |
| Coastside Fire Protection | Coastside Fire Protection | — | (650) 892 7211 | Other | Half Moon Bay · San Mateo County | — | — |
| Coastside Glass | Coastside Glass | chad@coastsideglass.com | (650) 454 4916 | Windows, patio, painters | Half Moon Bay · San Mateo County | — | — |
| Coastside Tile | Coastside Tile | — | (650) 444 3674 | Other | Pacifica · San Mateo County | — | — |
| Coastside Tree Service | Kordo A Fidel | — | (650) 451 3848 | Tree | El Granada · San Mateo County | — | — |
| Coastwest Fire Protection | Timothy Alan Jr West | — | (650) 784 6002 | Other | El Granada · San Mateo County | — | — |
| Cobell Construction INC | Jacob Kaplan Christie | info@cobellconstruction.com | (650) 744 2628 | GC, remodel, ADU | South San Francisco · San Mateo County | — | — |
| Cobri | Yuan Yi | — | (510) 850 6885 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Cobur Securities | Cobur Securities | — | (415) 370 6322 | Other | Loma Mar · San Mateo County | — | — |
| Coc Painting | Coc Painting | cesarpainting@gmail.com | (650) 679 0162 | Windows, patio, painters | Redwood City · San Mateo County | — | — |
| Cocconi Electric | Dennis Bruce Agresti | — | (650) 610 8586 | Electricians | Belmont · San Mateo County | — | — |
| Code Red Construction INC | Steven Paul Salinas | — | (650) 892 6227 | GC, remodel, ADU | Pacifica · San Mateo County | — | — |
| Cody Vermette Group INC | Richard Earl Cody | — | (650) 591 0757 | GC, remodel, ADU | Belmont · San Mateo County | — | — |