| Construction Crafters INC | Gacic Petar | pg@constructioncrafters.com | (858) 257 7502 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Construction Electric INC | Mary Beth Lockhart | — | (951) 789 8350 | Electricians | Riverside · Riverside County | — | — |
| Construction Genetics INC | Eric Enciso | — | (760) 468 8063 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Construction Maintenance Service | Scott Alan Farnam | alemendoza.cms@gmail.com | (951) 265 8043 | GC, remodel, ADU | Murrieta · Riverside County | — | — |
| Construction Plus | Steven Gilbert Wolny | — | (951) 652 9409 | GC, remodel, ADU | Hemet · Riverside County | — | — |
| Construction Select Builders | Barney Andrew Frank | — | (714) 883 3840 | GC, remodel, ADU | Menifee · Riverside County | — | — |
| Construction Services And Maintenance | Justin Paul Corey | — | (909) 522 8045 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Constructive Improvements | Constructive Improvements | — | (714) 501 0272 | GC, remodel, ADU | Norco · Riverside County | — | — |
| Construlux INC | Akkari Nabil | info@construlux.com | (714) 736 6335 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Contech - Construction Technology & Building Analyst | Anthony Brian Lum | — | (760) 519 1195 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Contempo Remodels | Contempo Remodels | — | (760) 333 5093 | GC, remodel, ADU | Bermuda Dunes · Riverside County | — | — |
| Contera Construction Corporation | Cristy Lee Varela | — | (951) 695 2800 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Continental Marble And Tile Company | David Bronson Guzman | — | (951) 284 1776 | Other | Corona · Riverside County | — | — |
| Continental Plumbing INC | Daniel Stephen Buckley | — | (951) 360 8300 | HVAC | Mira Loma · Riverside County | — | — |
| Continental Precision Pools INC | Craig David Ramirez | — | (951) 924 5141 | Pool | Moreno Valley · Riverside County | — | — |
| Contino Construction INC | Frank Ralph Contino | — | (530) 391 8200 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| Contour Building Design | Contour Building Design | — | (760) 232 6078 | GC, remodel, ADU | Palm Springs · Riverside County | — | — |
| Contour Stairs | Contour Stairs | — | (310) 678 5417 | Other | Nuevo · Riverside County | — | — |
| Contract Decor INC | Marc Roy Stewart | — | (760) 343 4444 | Other | Thousand Palms · Riverside County | — | — |
| Contractors Insul Material Services | Morales Moises Bautista | — | (714) 423 6485 | Other | Riverside · Riverside County | — | — |
| Contractors Services Company | Alex James Hamilton | — | (760) 275 7858 | Other | Palm Springs · Riverside County | — | — |
| Contrast Services LLC | Christopher Michael Kelly | — | (951) 210 6554 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Contreras Bros General Contractors | Emilio Anthony Contreras | — | (760) 880 8708 | GC, remodel, ADU | White Water · Riverside County | — | — |
| Contreras Tileworks Corp | Oscar Contreras | — | (760) 219 6910 | Other | Desert Hot Springs · Riverside County | — | — |
| Control Electric INC | Neil Andrew Fox | — | (951) 739 7399 | HVAC | Corona · Riverside County | — | — |
| Controlled Environment Specialist | Karl Ryan Fesenmeyer | — | (951) 870 5342 | HVAC | Corona · Riverside County | — | — |
| Convergent Communications INC | David Luis Lopez | — | (951) 588 6940 | Other | Riverside · Riverside County | — | — |
| Cook Coatings INC | Cary Doren Cook | — | (951) 296 2664 | Other roofers | Temecula · Riverside County | — | — |
| Cook Drywall Corporation | Barbara Gail Wagner | — | (951) 676 2246 | GC, remodel, ADU | Winchester · Riverside County | — | — |
| Cooks Fiberglass Reinforced Panels | Cooks Fiberglass Reinforced Panels | — | (951) 201 4564 | Other | Corona · Riverside County | — | — |
| Cool Air 1 | Cool Air 1 | — | (951) 445 7045 | HVAC | Moreno Valley · Riverside County | — | — |
| Cool Air Solutions Services LLC | Justin Raymond Holmquist | — | (951) 676 2665 | HVAC | Murrieta · Riverside County | — | — |
| Cool Bear Heating & Air INC | Felix Armando Hernandez Reyes | — | (951) 629 9489 | HVAC | San Jacinto · Riverside County | — | — |
| Cool Comfort Heating & Air | Victor Lita | — | (760) 990 3372 | HVAC | Wildomar · Riverside County | — | — |
| Cool Express Heating & Air Conditioning | Pamod Dilshan Samaranayaka | — | (951) 231 7731 | HVAC | Riverside · Riverside County | — | — |
| Cool Flow Air Conditioning & Heating LLC | Dennis Barriga | — | (760) 609 2453 | HVAC | La Quinta · Riverside County | — | — |
| Cool Guys Air Conditioning And Heating | Angel Anthony Cardozo | — | (760) 218 3750 | HVAC | Palm Springs · Riverside County | — | — |
| Cool Sunmer Window Tinting | Cool Sunmer Window Tinting | — | (760) 574 0605 | Other | Coachella · Riverside County | — | — |
| Coolair Tek Airconditioning Heating And Refrigeration | Almoutaoukil | — | (951) 250 0763 | HVAC | Beaumont · Riverside County | — | — |
| Coolest Air | Samuel Justin Rodriguez | — | (760) 485 7020 | HVAC | Indio · Riverside County | — | — |