| Cm Blue's Tiling | Gonzalez Candido Martinez | — | (510) 910 6438 | Other | Oakland · Alameda County | — | — |
| Cm Master Builders | Larry Venturia Woods | — | (510) 485 4449 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Cm Tomas Construction | Cesario Mateo Jr Tomas | — | (510) 676 2257 | GC, remodel, ADU | Union City · Alameda County | — | — |
| Cmg General Contractor INC | Miguel Angel Gamero-Espinosa | — | (510) 828 3008 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Cmjn Avt | Cmjn Avt | — | (925) 518 2268 | Other | Livermore · Alameda County | — | — |
| Coahuila Construction INC | Seyed Roohollah Hosseini | — | (510) 750 8384 | Electricians | Hayward · Alameda County | — | — |
| Coast Construction Company | Jessica Lyn Gorman | connect@coastconstruction.ca | (510) 533 7168 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Coastal Bay Builders LLC | Kevin R Grant | — | (925) 219 2596 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Coastal Construction Services LLC | Bruce Edward Green | — | (775) 345 6700 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Cobbs Construction | Jermaine Lajuna Cobbs | — | (510) 712 5563 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Cobian Drywall INC | Avila Omar Cobian | — | (650) 271 7323 | Other | Newark · Alameda County | — | — |
| Cobuild Construction Services INC | Kenneth Edward Wood | — | (510) 244 3663 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Coda Construction INC | Torrez Elias | etorrez1@comcast.net | (925) 785 6367 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| Code Archi | Noah Thomas Pitts | — | (510) 486 8282 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| Code Plus Builder | Code Plus Builder | — | (510) 520 1632 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Coester Construction | Joern Emil Coester | — | (510) 459 3199 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Cogley General Contracting | Brian William Cogley | — | (510) 295 8021 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Cohen Air Conditioning & Heating | Cohen Air Conditioning & Heating | — | (925) 339 3787 | HVAC | Livermore · Alameda County | — | — |
| Cokis Construction Company INC | Ramirez Guerrero Jorge | info@sullivan-construction.com | (408) 315-4254 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Cold Chain Refrigeration | Cold Chain Refrigeration | service@coldchainrefrigeration.com | (510) 856 6263 | HVAC | Hayward · Alameda County | — | — |
| Cold Room Solutions INC | Bradley B Bidwell | — | (925) 462 2500 | HVAC | Pleasanton · Alameda County | — | — |
| Cold Storage Design & Build INC | Brian William Kinsella | — | (510) 476 1700 | GC, remodel, ADU | Union City · Alameda County | — | — |
| Cold Storage Manufacturing INC | Mark Allan Troike | — | (510) 476 1700 | HVAC | Union City · Alameda County | — | — |
| Cold Storage Refrigeration INC | Chad Swan | — | (510) 476 1700 | HVAC | Union City · Alameda County | — | — |
| Cold Systems Refrigeration LLC | Ethan Daniel Munoz | — | (209) 715 8472 | HVAC | Livermore · Alameda County | — | — |
| Cold Water Builders INC | Antonio Geraldo Davis | — | (510) 909 2010 | GC, remodel, ADU | Emeryville · Alameda County | — | — |
| Cole's Carpet And Upholstery Company | Matt Dillon Cole | — | (510) 733 9716 | Other | Castro Valley · Alameda County | — | — |
| Colevan Electric INC | Gregory Keith Olson | — | (925) 314 9453 | HVAC | Pleasanton · Alameda County | — | — |
| Colin Groth Builders | Colin Groth Builders | — | (860) 309 3714 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Collier's Home Repair | Collier's Home Repair | — | (510) 562 4024 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Collins Group Remodeling | Collins Group Remodeling | — | (341) 223-3291 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Collins Plumbing | John Anthony Collins | — | (510) 654 5793 | Other | Oakland · Alameda County | — | — |
| Collins Roofing INC | James Philip Collins | — | (510) 444 2220 | Other roofers | Oakland · Alameda County | — | — |
| Colombian Brother | Colombian Brother | — | (650) 921 9857 | GC, remodel, ADU | Union City · Alameda County | — | — |
| Color Folio Design INC | Timothy Stephen Caton | info@colorfoliodesign.com | (510) 547 1419 | Windows, patio, painters | Emeryville · Alameda County | — | — |
| Color Me Mine | Color Me Mine | — | (510) 521-8893 | Windows, patio, painters | Alameda · Alameda County | — | — |
| Color Waze Painting | Manuel Rodriguez | — | (510) 406 8264 | Windows, patio, painters | Oakland · Alameda County | — | — |
| Columbia Electric INC | Kimberly Nichole Scruggs | — | (510) 430 9505 | Electricians | San Leandro · Alameda County | — | — |
| Comfort Air Conditioning & Heating | Comfort Air Conditioning & Heating | — | (510) 706 0639 | HVAC | Hayward · Alameda County | — | — |
| Comfort Air Mechanical Systems INC | Xiao Hong Chen | — | (510) 217 8980 | HVAC | Alameda · Alameda County | — | — |