| Cooks Finish Carpentry INC | Daniel Joseph Cook | — | (949) 933 1295 | Other | Costa Mesa · Orange County | — | — |
| Cool Air Refrigeration | Juan Carlos Trejo | — | (714) 277 3711 | HVAC | Anaheim · Orange County | — | — |
| Cool Air Technologies INC | William Francis Mc Intosh | — | (714) 731 9292 | HVAC | Tustin · Orange County | — | — |
| Cool City | Cool City | — | (949) 350 6203 | HVAC | Rancho Santa Margarita · Orange County | — | — |
| Cool Correct Air Corp | Brandon William Lee Morris | — | (949) 357 5094 | HVAC | Laguna Beach · Orange County | — | — |
| Cool Rocks Landscaping | Cool Rocks Landscaping | — | (714) 317 1697 | Windows, patio, painters | Santa Ana · Orange County | — | — |
| Cool Roof Service | David Hoki Yoon | — | (714) 224 8394 | Other roofers | Fullerton · Orange County | — | — |
| Cool Roofing INC DBA 1st Choice Roofing | David James Babashoff | — | (949) 375 4175 | Other roofers | Huntington Beach · Orange County | — | — |
| Cool White Sciences INC | Cardenas Rafael | — | (323) 925 6045 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| Coolaris HVAC INC | Joshua Hong | — | (626) 771 7185 | HVAC | Brea · Orange County | — | — |
| Cooldepot A/c | Cooldepot A/c | — | (714) 335 3221 | HVAC | La Palma · Orange County | — | — |
| Coolets Heating And Airconditioning INC | Erwin Manuel Dizon | — | (714) 473 3798 | HVAC | Anaheim · Orange County | — | — |
| Cooling & Heating Repair INC | Vladislav Samoilyuk | — | (657) 272 5105 | HVAC | Fullerton · Orange County | — | — |
| Cooling Bear Construction INC | Jamie Sharrow Hunley | — | (747) 238 2436 | GC, remodel, ADU | Ladera Ranch · Orange County | — | — |
| Coolpros Heating And Air | Mario Alberto Garcia Carrillo | — | (562) 319 0905 | HVAC | Anaheim · Orange County | — | — |
| Coolsys Commercial & Industrial Solutions INC | Bryan Carl Beitler | — | (904) 210 0842 | HVAC | Brea · Orange County | — | — |
| Coombs Construction | John Clifford Coombs | — | (714) 349 0454 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Cooper Construction | Mark Andrew Cooper | — | (714) 962 4647 | GC, remodel, ADU | Huntington Beach · Orange County | — | — |
| Cooper Doors INC | David Paul Cooper | — | (714) 666 0888 | Other | Anaheim · Orange County | — | — |
| Cooper Floors INC | Richard Blake Orgill | — | (714) 979 7888 | Other | Fountain Valley · Orange County | — | — |
| Coopman Plastering INC | David Scott Coopman | — | (714) 476 3490 | Other | Huntington Beach · Orange County | — | — |
| Coorg Corporation | Chendanda Bopayya Nanda | — | (714) 999 6565 | Other roofers | Anaheim · Orange County | — | — |
| Cope Industries | Cope Industries | — | (714) 323 6672 | GC, remodel, ADU | Seal Beach · Orange County | — | — |
| Copeland Enterprises INC | John Hudson Copeland | — | (714) 381 7930 | GC, remodel, ADU | Mission Viejo · Orange County | — | — |
| Copp Contracting Incorporated | Erlinda Copp | — | (714) 522 7754 | Other | Buena Park · Orange County | — | — |
| Copper Construction LLC | Jia Xie | interested@domainmarket.com | (626) 677 1321 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Copperfield Electric | Rene Arthur Hernandez | copperfieldelectric@gmail.com | (626) 622 9694 | Electricians | Tustin · Orange County | — | — |
| Copperfield Electric Of Irvine | Copperfield Electric Of Irvine | — | (949) 518-0045 | Electricians | Tustin · Orange County | — | — |
| Copperoreo Construction | John E Jacobson | — | (714) 330 4747 | GC, remodel, ADU | Newport Beach · Orange County | — | — |
| Coral Communications | Ernesto Jimenez | — | (951) 732 1455 | Other | Huntington Beach · Orange County | — | — |
| Coral Ridge Design | Coral Ridge Design | — | (949) 234 9775 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| Coram HVAC Corp | Seung-Chul Lim | info@coramhvac.com | (714) 603 7442 | HVAC | Anaheim · Orange County | — | — |
| Corbin Reeves Construction | Michael David Reeves | info@corbinreeves.com | (714) 540 3700 | GC, remodel, ADU | Costa Mesa · Orange County | — | — |
| Cordovas Painting | Cordovas Painting | — | (949) 612 5476 | Windows, patio, painters | Orange · Orange County | — | — |
| Core Connect I T INC | Joseph Gerard Cereghino | — | (714) 357 4009 | Other | Fountain Valley · Orange County | — | — |
| Core Electric INC | John Brian Johnson | — | (714) 899 4290 | Electricians | Garden Grove · Orange County | — | — |
| Core Fiber INC | Kurtis Darwin Huckans | — | (949) 300 4981 | Other | Laguna Hills · Orange County | — | — |
| Core P & C | Core P & C | — | (213) 999 1110 | GC, remodel, ADU | Brea · Orange County | — | — |
| Core Technologies INC | Corben Christopher Craig | support@coretechnologies.com | (714) 624 5578 | Electricians | Placentia · Orange County | — | — |
| Corefinish Painting | Gerald Giovanni Guevara Villeda | — | (657) 246 8983 | Windows, patio, painters | Huntington Beach · Orange County | — | — |