| Circle City Millwork INC | Gabriel Diaz | — | (951) 531 8050 | Other | Corona · Riverside County | — | — |
| Circle City Plumbing | Marco Antonio Martinez | — | (714) 866 6663 | Other | Corona · Riverside County | — | — |
| Circle City Roofing INC | Michael Gene Dalfior | — | (951) 736 5252 | Other roofers | Norco · Riverside County | — | — |
| Circle City Tile | Don Sherwood Rapp | — | (714) 507 6302 | Other | Perris · Riverside County | — | — |
| Cisco Aguilar | Cisco Aguilar | — | (760) 296 5101 | Pool | Indio · Riverside County | — | — |
| Cisco Martinez Electric | Francisco Diaz Martinez | — | (760) 413 8714 | Electricians | Indio · Riverside County | — | — |
| Cisco's Custom Masonry | Cisco's Custom Masonry | — | (951) 660 6695 | Other | Perris · Riverside County | — | — |
| Cisneros Construction | Cisneros Samuel | — | (951) 250 5484 | Other | Moreno Valley · Riverside County | — | — |
| Cissell Construction Co INC | Gary Patrick Cissell | — | (951) 813 8540 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Citadel Communications Group Corporation | Juvenal Gonzalez | — | (760) 666 1122 | Electricians | Indio · Riverside County | — | — |
| Citadel Glazing Structures LLC | Daniel James Gouvion | daniel@citadelglazingstructures.com | (714) 868 9166 | Windows, patio, painters | Riverside · Riverside County | — | — |
| Citizen One Construction | Michael Roger Clark | — | (619) 843 1534 | GC, remodel, ADU | Winchester · Riverside County | — | — |
| Citrus Construction | Laurentiu Robert Olah | — | (951) 333 0192 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| City Boys Plumbing | Herrera Miguel Rodrigues | — | (951) 490 2045 | Other | Riverside · Riverside County | — | — |
| City Home Landscaping INC | Suhua Zeng | — | (626) 236 0791 | Windows, patio, painters | Eastvale · Riverside County | — | — |
| City Wide Plumbing Heating And Air Conditioning | David Edward Knauff | — | (562) 507 3503 | HVAC | Moreno Valley · Riverside County | — | — |
| Civil West General Engineering INC | David Ryan Niederhauser | — | (714) 981 4531 | Other | Riverside · Riverside County | — | — |
| Civil-environmental-survey Group INC DBA C E S | James Patrick Keegan | — | (951) 808 8585 | Other | Temecula · Riverside County | — | — |
| Cj Concrete Cutting & Demo INC | Cesar Alonso Jaime | — | (619) 576 4861 | Other | Menifee · Riverside County | — | — |
| Cj Deboer Engineering & Septic INC | Carlton John Deboer | — | (951) 205 0155 | Other | Perris · Riverside County | — | — |
| Cj Landscaping | Cj Landscaping | eben@eyebytes.com | (951) 514 9640 | Windows, patio, painters | Wildomar · Riverside County | — | — |
| Cj Painting | Cj Painting | — | (310) 908 2310 | Windows, patio, painters | Norco · Riverside County | — | — |
| Cj's Electrical Company INC | Carlos Alberto Jr Alvarez | — | (909) 636 6382 | Electricians | Moreno Valley · Riverside County | — | — |
| Cjl Construction | Cesar Juan Leon | — | (951) 333 8786 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Cjm Construction | Cailean Jacob Meyer | — | (951) 294 2655 | GC, remodel, ADU | Hemet · Riverside County | — | — |
| Cjs Cooling Tower Services | Christopher Joseph Shea | cjscts@gmail.com | (951) 278 0283 | HVAC | Norco · Riverside County | — | — |
| Ck Construction | Craig Allen Kyrouac | vathanak451@gmail.com | (562) 476 5733 | GC, remodel, ADU | Wildomar · Riverside County | — | — |
| Cke Door & Window | Craig Alan Busell | — | (714) 317 7139 | Windows, patio, painters | Winchester · Riverside County | — | — |
| Ckm Pipeline Inspection Services | Todd Kenton Close | — | (909) 721 4201 | Other | Temecula · Riverside County | — | — |
| Ckr Home Corporation | William Jason Wagner | info@ckrhome.com | (909) 816 3477 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Cl Arredondo's And Fam Gc Enterprises | Cesar Antonio Arredondo Giron | — | (949) 887 7638 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Cl Electric | Cory James Lopez | contact@cl-electric.com | (619) 451-0050 | Electricians | Riverside · Riverside County | — | — |
| Cl Networking LLC | Lance Edward Monteros | — | (949) 929 3423 | Other | Temecula · Riverside County | — | — |
| Claiborne Construction | Gerold Lee Claiborne | — | (747) 228 7865 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Clark Contractors INC DBA Cci Builders | William Lavern Clark | — | (949) 795 0236 | GC, remodel, ADU | Murrieta · Riverside County | — | — |
| Clark Development Corporation | Shaun Linn Clark | — | (760) 989 0099 | GC, remodel, ADU | Indio · Riverside County | — | — |
| Clark Drywall Solutions | Brandon James Clark | — | (714) 606 3741 | Other | Riverside · Riverside County | — | — |
| Clark Grading INC | Russell Lynn Clark | — | (951) 785 5145 | Other | Riverside · Riverside County | — | — |
| Clark Pest Control | Clark Pest Control | — | (951) 450-8866 | Pest, tile roofs | Riverside · Riverside County | — | — |
| Clark Welding | Tyler Gene Clark | — | (951) 331 0939 | Other | Winchester · Riverside County | — | — |