| Cornerstone Concrete INC | Matthew Richard Valente | — | (951) 279 2221 | Other | Corona · Riverside County | — | — |
| Cornerstone Construction | Billy Wayne Spry | gwebb@cornerstone-construction.com | (832) 259-2520 | GC, remodel, ADU | Perris · Riverside County | — | — |
| Cornerstone Construction & Development INC | Jim Edwin Noland | — | (818) 253 6407 | GC, remodel, ADU | Indian Wells · Riverside County | — | — |
| Cornerstone Flooring Solutions INC | Jesus Alberto Lopez | — | (760) 275 0437 | Other | La Quinta · Riverside County | — | — |
| Cornerstone Hardscape | Anthony Robert Rodriguez | — | (951) 850 0964 | Other | Temecula · Riverside County | — | — |
| Cornerstone Landcare INC | Michael Richard Goltry | — | (951) 779 8000 | Windows, patio, painters | Riverside · Riverside County | — | — |
| Cornerstone Masonry | Cornerstone Masonry | — | (909) 225 1422 | Other | Riverside · Riverside County | — | — |
| Cornerstone Mirror Glass | Cornerstone Mirror Glass | — | (760) 774 9241 | Windows, patio, painters | Desert Hot Springs · Riverside County | — | — |
| Cornerstone Paving & Sealcoating | Cornerstone Paving & Sealcoating | — | (951) 333 8254 | Other | Perris · Riverside County | — | — |
| Cornett Construction | Darrell Ross Cornett | — | (951) 845 7932 | GC, remodel, ADU | Banning · Riverside County | — | — |
| Corona Clay Company | Kiana Jean Deleo | — | (951) 277 2667 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Corona Constructors | John William O'doherty | info@coronaconstructors.com | (951) 340 1286 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Corona Del Mar Roofing INC | Miguel Angel Sanchez | — | (951) 268 6365 | Other roofers | Eastvale · Riverside County | — | — |
| Corona Glass INC | Terry Alan Dahlke | interested@domainmarket.com | (951) 735 5630 | Windows, patio, painters | Corona · Riverside County | — | — |
| Corona Landscaping & Tree Service INC | Jose Loreto Corona | — | (310) 259 4463 | Windows, patio, painters | Jurupa Valley · Riverside County | — | — |
| Corona Lighting And Electric INC | Kristopher Scott Warren | — | (760) 321 8700 | Electricians | Palm Desert · Riverside County | — | — |
| Corona Pacific Heating & Air Conditioning | Corona Jorge | — | (760) 413 2369 | HVAC | Indio · Riverside County | — | — |
| Corona Painting | Corona Painting | — | (951) 733 4303 | Windows, patio, painters | Eastvale · Riverside County | — | — |
| Corona Plumbing INC | Robert Allen Jr Wood | — | (714) 727 9660 | Other | Corona · Riverside County | — | — |
| Corona Pool Repair | Corona Pool Repair | — | (714) 401 7426 | Pool | Eastvale · Riverside County | — | — |
| Corona's Remodeling | Corona's Remodeling | — | (760) 899 4285 | GC, remodel, ADU | Desert Hot Springs · Riverside County | — | — |
| Coronel Demolition INC | Coronel Antonio | — | (562) 376 1966 | Other | Riverside · Riverside County | — | — |
| Coronel Homes & Design INC | Esequiel Machado Coronel | — | (760) 775 1234 | GC, remodel, ADU | Indio · Riverside County | — | — |
| Corpo H Velasco Landscaping | Sanchez Hernan Velasco | — | (760) 315 2118 | Windows, patio, painters | Lake Elsinore · Riverside County | — | — |
| Corridor Comfort Heat AC | Corridor Comfort Heat AC | — | (760) 296 4717 | HVAC | Mecca · Riverside County | — | — |
| Corry Nouwels | Corry Nouwels | — | (951) 224 7148 | Other | Nuevo · Riverside County | — | — |
| Cortes Electric INC | Antonio Ruben Cortes Sandoval | — | (760) 844 0204 | Electricians | Indio · Riverside County | — | — |
| Cortes Plumbing Service And Drains | Talavera Eduardo Cortes | — | (951) 229 7012 | Other | Menifee · Riverside County | — | — |
| Cortez & Sons Concrete Construction INC | Hugo Juventino Cortez Pacheco | — | (951) 732 4470 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Cortez Concrete INC | Delia Isabel Cortez | — | (951) 977 8032 | Other | Riverside · Riverside County | — | — |
| Cortez Painting | Cortez Painting | — | (760) 272 0927 | Windows, patio, painters | Desert Hot Springs · Riverside County | — | — |
| Corteza Landscaping And Tree Service DBA Corteza Landscaping | Jocelyne Martinez | — | (760) 497 2002 | Windows, patio, painters | Temecula · Riverside County | — | — |
| Cortum Communications INC | Michael Dean Cortum | — | (951) 296 2199 | Other | Murrieta · Riverside County | — | — |
| Cosentino Plumbing | Cosentino Plumbing | — | (909) 631 1578 | Other | Mira Loma · Riverside County | — | — |
| Cosmetic Stucco And Repair | Cosmetic Stucco And Repair | — | (951) 497 8950 | Other | Menifee · Riverside County | — | — |
| Costa Lake Appliance Installation | Lilia Facio | — | (626) 626 0062 | Other | Lake Elsinore · Riverside County | — | — |
| Costanzo Development Services | Matthew Ryan Costanzo | — | (951) 240 1222 | Electricians | Murrieta · Riverside County | — | — |
| Costo Construction Corp | Eric Christian Costo | info@costoconstruction.com | (760) 766 2333 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| Cota Brothers | Cota Brothers | — | (760) 989 9730 | HVAC | Coachella · Riverside County | — | — |
| Cota Electric | Cota Armando | — | (951) 551 3848 | Electricians | Temecula · Riverside County | — | — |