| C S I Custom Homes | Mike Albert Maldonado | — | (650) 369 2794 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| C S Of S C INC | Robert Chosin Canevari | — | (650) 598 0100 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| C T Hardwood Floors | C T Hardwood Floors | — | (650) 533 1661 | Other | Redwood City · San Mateo County | — | — |
| C Two Construction LLC | Luis Miguel Saavedra | — | (415) 515 0560 | GC, remodel, ADU | South San Francisco · San Mateo County | — | — |
| C W C General Contractor | C W C General Contractor | — | (650) 245 8421 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| C3 Construction | Stephen Edward Murphy | — | (415) 994 9400 | GC, remodel, ADU | Daly City · San Mateo County | — | — |
| Ca Red Oak Builder Corp | Eusebio Arnulfo Contreras Velasco | — | (650) 771 3775 | GC, remodel, ADU | So San Francisco · San Mateo County | — | — |
| Ca Sunrise Construction Solution INC | Jose R Alvarado | — | (415) 424 8801 | Electricians | San Bruno · San Mateo County | — | — |
| Ca-bolco Construction Co | Edric L Bol | — | (206) 399 7930 | HVAC | Burlingame · San Mateo County | — | — |
| Cable Shmable INC | Abdukarimjon Azizov | — | (415) 910 2885 | Other | South San Francisco · San Mateo County | — | — |
| Cabrera's Painting | Cabrera's Painting | cabreraspaintingca@gmail.com | (415) 319 5636 | Windows, patio, painters | Pacifica · San Mateo County | — | — |
| Cabrillo Construction Company INC | Ruo Wu Chen | impallari@gmail.com | (415) 810 2408 | GC, remodel, ADU | Millbrae · San Mateo County | — | — |
| Cacc Construction & Consulting INC DBA Adrian Smith Construction | Adrian Mitchell Smith | — | (650) 400 5365 | GC, remodel, ADU | San Carlos · San Mateo County | — | — |
| Cacci Construction INC | Michael Louis Cacci | — | (650) 508 0778 | GC, remodel, ADU | San Carlos · San Mateo County | — | — |
| Caccia Home Services | Juliana Rose Johnson | — | (650) 342 5363 | Electricians | Burlingame · San Mateo County | — | — |
| Cal - Nor Bay Painting | Cal - Nor Bay Painting | — | (650) 303 2763 | Windows, patio, painters | San Mateo · San Mateo County | — | — |
| Cal - Pac Roofing Of San Mateo | Susan Stubbs Rossi | — | (650) 286 0450 | Other roofers | San Mateo · San Mateo County | — | — |
| Cal - Pacific Construction INC | John Wah Chan | info@calpacificconstruction.com | (858) 774-3612 | Electricians | Pacifica · San Mateo County | — | — |
| Cal Pacific Systems | Robert Chi Lo | info@calpacificsystems.com | (415) 252 8600 | HVAC | Brisbane · San Mateo County | — | — |
| Cal Painting | Arsenio Ferreira Ferreira | — | (408) 482-1492 | Windows, patio, painters | San Mateo · San Mateo County | — | — |
| Cal State Roofing Co INC | Minju Weon | — | (415) 954 2278 | Other roofers | South San Francisco · San Mateo County | — | — |
| Cal-star Paving & Grading | Cal-star Paving & Grading | — | (510) 305 2158 | Other | Redwood City · San Mateo County | — | — |
| Cal-west Plumbing | Cal-west Plumbing | — | (650) 598 9108 | Other | San Carlos · San Mateo County | — | — |
| Calbest Roofing INC | Steve Kim | — | (415) 933 9255 | Other roofers | Redwood City · San Mateo County | — | — |
| Caledonian Masonry INC | Paul Martin Gallagher | — | (650) 525 9154 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| Calex Builders | Calex Builders | — | (650) 771 8983 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Cali - Nite - Lites | Cali - Nite - Lites | — | (650) 537 9298 | Windows, patio, painters | San Mateo · San Mateo County | — | — |
| Cali Electrical LLC | Reuben Odell Flax | — | (650) 274 5112 | Electricians | Redwood City · San Mateo County | — | — |
| Caliber Construction Group INC | Yushen Hu | — | (415) 623 9154 | GC, remodel, ADU | Burlingame · San Mateo County | — | — |
| Calibuilder | Masoumi | info@calibuilder.com | (650) 822-1121 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| Calico Plumbing | Calico Plumbing | — | (650) 595 4065 | Other | San Carlos · San Mateo County | — | — |
| California Best Electricians | California Best Electricians | — | (650) 563-5786 | Electricians | Burlingame · San Mateo County | — | — |
| California Buckeye Landscaping | California Buckeye Landscaping | — | (650) 224 9611 | Windows, patio, painters | Belmont · San Mateo County | — | — |
| California Canvas | California Canvas | — | (650) 873 3487 | Other | Pacifica · San Mateo County | — | — |
| California Custom Creations | California Custom Creations | eddie@californiacustomcreations.com | (408) 316 6293 | Windows, patio, painters | Half Moon Bay · San Mateo County | — | — |
| California Electric Co | Joseph Anthony Dini | hello@california-electric.com | (650) 342 5949 | Electricians | Burlingame · San Mateo County | — | — |
| California First Class Construction INC | Abdelrahim Khalid Elnabulsi | — | (650) 787 6739 | GC, remodel, ADU | Pacifica · San Mateo County | — | — |
| California Framing Construction | Juan Arroyo Gutierrez | jgcalframing@yahoo.com | (650) 483 0326 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| California Green Builder | California Green Builder | — | (415) 235 6658 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| California Home Management | California Home Management | — | (415) 519 3466 | GC, remodel, ADU | Woodside · San Mateo County | — | — |