| Crystal Home Design | Crystal Home Design | — | (714) 886 8832 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Crystal Painting Co | Peter Lee | — | (714) 636 8292 | Windows, patio, painters | Seal Beach · Orange County | — | — |
| Crystalcrete Concrete Polishing Coatings | Jon Albert Deyan | — | (714) 345 3820 | Other | Placentia · Orange County | — | — |
| Cs Mechanical | Cs Mechanical | support@csmechanical.zohodesk.com | (562) 206 6964 | HVAC | Huntington Beach · Orange County | — | — |
| Cs Painting | Cs Painting | — | (626) 331 4700 | Windows, patio, painters | Fullerton · Orange County | — | — |
| Cs Renovations INC | Francisco Javier Cisneros Solorio | — | (949) 759 2810 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Cs Signs LLC | Salinas Carlos | — | (714) 721 7604 | Electricians | Ladera Ranch · Orange County | — | — |
| Cs Tech Construction | Chris Sunghyon Shin | — | (213) 265 5709 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| Csa Constructors INC | Richard Arnold Schmitt | — | (562) 602 0482 | GC, remodel, ADU | Brea · Orange County | — | — |
| Csc Construction | Alin Radu Lupean | — | (714) 463 0977 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| Cscg Enterprises INC DBA Tmc Enterprises | Garcia Carlos | — | (714) 771 1777 | GC, remodel, ADU | Orange · Orange County | — | — |
| Csg Construction | Salcedo Carlos | — | (714) 615 9990 | GC, remodel, ADU | Cypress · Orange County | — | — |
| Csi Construction | Osman Jesus Castillo | — | (714) 827 8400 | GC, remodel, ADU | Costa Mesa · Orange County | — | — |
| Csira Design Build LLC | Chip Csira | — | (949) 613 4455 | GC, remodel, ADU | Laguna Beach · Orange County | — | — |
| Csl Builders | Chsung Say Lam | — | (714) 576 4868 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| Csl Building INC | Patrice Yvon Reconnu | — | (714) 728 5642 | GC, remodel, ADU | Huntington Beach · Orange County | — | — |
| Csl General Construction INC | Francisco Saavedra | — | (714) 305 7021 | GC, remodel, ADU | Stanton · Orange County | — | — |
| Cslm Construction INC | Cornelius Marinescu | — | (714) 683 4309 | GC, remodel, ADU | Foothill Ranch · Orange County | — | — |
| Csm Electric INC | Cristian Alexander Perez Valladares | — | (657) 342 7594 | Electricians | Santa Ana · Orange County | — | — |
| Csp Plumbing INC | Craig Andrew Sedlak | — | (949) 282 7823 | Other | Aliso Viejo · Orange County | — | — |
| Ct Air Conditioning | Ct Air Conditioning | — | (714) 271 8129 | HVAC | Midway City · Orange County | — | — |
| Ct Construction Services INC | Craig Alray Tokarski | — | (949) 395 3693 | GC, remodel, ADU | Laguna Niguel · Orange County | — | — |
| Ct Design INC | Tom Vinh | — | (714) 892 7796 | GC, remodel, ADU | Stanton · Orange County | — | — |
| Ct Electric | Ionut Cristian Tirla | — | (714) 865 2187 | Electricians | Anaheim · Orange County | — | — |
| Cubed M Construction LLC | Mark Michael Maietta | — | (714) 329 8518 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Cubic Engineering INC | Koja Ahmad | sales@cubicengineering.com | (949) 228 8249 | GC, remodel, ADU | Costa Mesa · Orange County | — | — |
| Cuccia Construction | Gary Wayne Cuccia | — | (949) 370 9807 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| Cuesta Construction Co | David Drew Clark | — | (714) 920 8442 | GC, remodel, ADU | Costa Mesa · Orange County | — | — |
| Cummings Custom Tile And Stone | Cummings Custom Tile And Stone | — | (949) 492 9896 | Other | San Clemente · Orange County | — | — |
| Cummins Development LLC | Ryan Michael Cummins | cumminsdevelopment@gmail.com | (714) 679 7102 | GC, remodel, ADU | Costa Mesa · Orange County | — | — |
| Cundiff Steel Fabricating & Erecting | Cynthia Irene Summers | — | (714) 637 2211 | Other | Orange · Orange County | — | — |
| Cunningham Construction Co | Laurence Boothe Cunningham | info@cunninghamconstruction.com | (949) 413 0495 | GC, remodel, ADU | Lake Forest · Orange County | — | — |
| Cunningham Doors & Windows INC DBA Cunningham Construction | Dayle Edward Cunningham | info@cunninghamwindows.com | (714) 258 2500 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Cuong An Nguyen | Cuong An Nguyen | — | (714) 530 4957 | HVAC | Garden Grove · Orange County | — | — |
| Cura Construction Services | Seth J Fenn | — | (949) 272 8643 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Curated Studio Flooring | Curated Studio Flooring | — | (949) 283 0085 | Other | Newport Beach · Orange County | — | — |
| Curb Appeal Coatings | Curb Appeal Coatings | — | (714) 471 8530 | Windows, patio, painters | Fullerton · Orange County | — | — |
| Cureco INC | Brian Irvin Cure | — | (714) 536 8839 | GC, remodel, ADU | Huntington Beach · Orange County | — | — |
| Curnowornever Enterprises LLC | Ryan Christian Curnow | — | (949) 506 0650 | GC, remodel, ADU | Lake Forest · Orange County | — | — |
| Curran Stone And Tile | Curran Stone And Tile | — | (858) 775 6722 | Other | Laguna Woods · Orange County | — | — |