| Chris Conklin Construction | Chris Edward Conklin | — | (530) 277 7246 | GC, remodel, ADU | Dixon · Solano County | — | — |
| Chris Perry Construction | Christopher Scott Perry | — | (925) 250 4167 | GC, remodel, ADU | Benicia · Solano County | — | — |
| Christian Brothers Lining Co | Roderick Thomas Byrd | — | (661) 645 9724 | Other | Fairfield · Solano County | — | — |
| Chuck Lombard Painting | Chuck Lombard Painting | — | (707) 301 1655 | Windows, patio, painters | Vacaville · Solano County | — | — |
| Cimico Signs | Cimico Signs | — | (707) 447 1500 | Other | Vacaville · Solano County | — | — |
| Cindy Marie Klyberg | Cindy Marie Klyberg | — | (707) 249 8108 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Citadel Roofing And Solar | Folk Dieter | — | (707) 446 5500 | Other roofers | Vacaville · Solano County | — | — |
| City Plumbing | City Plumbing | — | (707) 655 2055 | Other | Vallejo · Solano County | — | — |
| Ck Construction Pros INC | Nathan Darius Cartwright | — | (509) 680 7590 | GC, remodel, ADU | Benicia · Solano County | — | — |
| Cklein Engineering LLC | Christopher Matthew Klein | — | (707) 297 5614 | Other | Benicia · Solano County | — | — |
| Clark & Son's Painting And Decorating INC | Janet Bernice Clark | — | (916) 402 3186 | Windows, patio, painters | Vallejo · Solano County | — | — |
| Clarke Construction | Michael Gregory Clarke | — | (704) 419 9886 | GC, remodel, ADU | Vallejo · Solano County | — | — |
| Clayton Nicholas Van Rooyen | Clayton Nicholas Van Rooyen | — | (707) 624 9157 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Clean Breeze Air | Clean Breeze Air | — | (408) 202 9693 | HVAC | Fairfield · Solano County | — | — |
| Cleanair Solutions INC | Alex Stanley Kalafatis | — | (707) 864 9499 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Clear Creek Construction | Kevin David Burns | — | (707) 363 1684 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Clear Image Sign Co | Ty Lewis Quilling | — | (707) 422 6237 | Other | Suisun City · Solano County | — | — |
| Clear View Window Cleaning | Clear View Window Cleaning | christopher@clearviewnc.com | (858) 229-3494 | Windows, patio, painters | Solana Beach · Solano County | — | — |
| Cliff Neal Enterprises INC | Jeffrey Lawrence Duncan | — | (707) 365 6955 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Clifton's Tree Service | Michael Dale Clifton | — | (707) 330 7954 | Tree | Vacaville · Solano County | — | — |
| Clint V Lorch Construction And Maintenance | Clint Vernon Lorch | — | (925) 408 6037 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Clm Pressure Washing | Yusef Cabral Mcneil | — | (707) 450 7567 | Other | Fairfield · Solano County | — | — |
| Cloyd Electric INC | Cloyd Altea Belarmino | — | (707) 213 8893 | Electricians | Vacaville · Solano County | — | — |
| Cm Plumbing INC | Carlos Alexander Mejia | — | (707) 280 9093 | Other | Vallejo · Solano County | — | — |
| Cm&l Roofing | Hernandez Gusman Constantino | — | (415) 375 1961 | Other roofers | Fairfield · Solano County | — | — |
| Cnc Network Solutions | John Theodore Kowalsky | — | (707) 422 0791 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Coastal Construction | Trever William Johnson | — | (510) 672 7502 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Coastline Arc Industries | Carlos Darcy Gutierrez Meza | — | (209) 261 8880 | Other | Benicia · Solano County | — | — |
| Cobra Pipeline Co INC | Jose S Lopez | — | (707) 384 8059 | Other | Suisun · Solano County | — | — |
| Code Three Fire And Safety | Code Three Fire And Safety | — | (707) 429 5323 | Other | Suisun · Solano County | — | — |
| Colbaugh Construction | Robert Alvin Colbaugh | — | (707) 359 9575 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Colibri Construction & Engineering INC | Carlos Barojas | — | (707) 249 3419 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Color-tech Concrete Systems | Color-tech Concrete Systems | — | (805) 445 0099 | Other | Vacaville · Solano County | — | — |
| Comfort Systems HVAC | Comfort Systems HVAC | — | (707) 771 5329 | HVAC | Benicia · Solano County | — | — |
| Commercial Services | Edward Nathaniel Davis | — | (916) 284 3334 | GC, remodel, ADU | Suisun City · Solano County | — | — |
| Community Housing Opportunities Corporation | Manuela Marie Silva | — | (707) 759 6043 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Community Playgrounds INC | Henry Curtis Iii Wear | — | (415) 892 8100 | Other | Vallejo · Solano County | — | — |
| Competition Construction | James Dean Kelly | — | (707) 689 4770 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Complete Civil Contractors | Isaias Martinez-Soto | — | (530) 526 9291 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Complete Janitorial And Construction Cleaning Services | Boyeyenge Ngoy | — | (707) 399 7132 | Other | Fairfield · Solano County | — | — |