| Kitchen Masters | Kitchen Masters | — | (951) 780 4944 | Other | Riverside · Riverside County | — | — |
| Kitchen Masters Construction Services INC | Stephen Michael Bruns | — | (951) 538 3516 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Kitchens & Baths By Lynn INC | Carrie Lynn Wallace | — | (760) 568 2054 | GC, remodel, ADU | Indian Wells · Riverside County | — | — |
| Kj's Heating And Air INC | Kelly Michael Hudler | — | (951) 837 4777 | HVAC | Wildomar · Riverside County | — | — |
| Klarer Construction | Marcus Conrad Klarer | — | (951) 852 5959 | GC, remodel, ADU | Idyllwild · Riverside County | — | — |
| Kleveno Concrete | Kleveno Concrete | — | (951) 789 0225 | Other | Riverside · Riverside County | — | — |
| Kling Pool Service & Repairs | Jenny Lee Kling | — | (714) 308 4132 | Pool | Hemet · Riverside County | — | — |
| Klr Engineering INC | Matthew Peter Lysiak | — | (951) 319 1817 | Other | Murrieta · Riverside County | — | — |
| Klug Automation INC | James Ray Klug | — | (951) 678 7130 | Other | Lake Elsinore · Riverside County | — | — |
| Km Construction | Kerry Michael Moya | — | (951) 415 4281 | GC, remodel, ADU | Murrieta · Riverside County | — | — |
| Km Patio Covers | Tracy Lee Murvine | kmpatiocovers@gmail.com | (909) 838 6779 | GC, remodel, ADU | Menifee · Riverside County | — | — |
| Kma HVAC & Construction INC | Linda Jane Fitzgerald | — | (951) 486 0337 | HVAC | Moreno Valley · Riverside County | — | — |
| Kmac Desert Plumbing | Kmac Desert Plumbing | — | (760) 318 0847 | Other | Cathedral City · Riverside County | — | — |
| Kml Services INC | Jerome William Vitta | info@kml-services.com | (949) 955 2017 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Knall Enterprises | Christian Iosif Knall | — | (310) 703 4849 | Electricians | Palm Desert · Riverside County | — | — |
| Knapp Landscaping | Knapp Landscaping | — | (760) 771 0181 | Windows, patio, painters | La Quinta · Riverside County | — | — |
| Knecht Plastering And General Construction | Kim John Knecht | — | (909) 841 6960 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Kngdm Builders LLC | David Joseph Deroche | — | (951) 905 0903 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Knighten Electric | Michael Alan Knighten | — | (909) 210 7003 | Electricians | Menifee · Riverside County | — | — |
| Knockout Demolition INC | Lyle William Mitchell | — | (951) 479 8812 | Other | Corona · Riverside County | — | — |
| Knr Construction INC | Ryan Manning Eddy | gerrit.werner14@icloud.com | (951) 545 3890 | GC, remodel, ADU | Norco · Riverside County | — | — |
| Knrg Electric | Kristian Emmanuel Lopez | — | (619) 862 8459 | Electricians | Hemet · Riverside County | — | — |
| Koch Heating & Air Conditioning INC | Richard Max Koch | — | (951) 696 5615 | HVAC | Murrieta · Riverside County | — | — |
| Kodiak Construction Services | James Steven Riggio | — | (714) 944 2487 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| Kodiak Painting INC | Jason Christen Morton | — | (951) 403 3444 | Windows, patio, painters | Beaumont · Riverside County | — | — |
| Koenig Construction | David Lawrence Koenig | — | (951) 693 5311 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Kofler Consulting Agriculture & Landscape | Kofler Consulting Agriculture & Landscape | — | (951) 240 8217 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Kohler Electric | Barrett Daniel Kohler | — | (909) 213 9525 | Electricians | Cherry Valley · Riverside County | — | — |
| Koi Construction LLC | Afa Noble Green | — | (951) 520 6379 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Kokos Construction | Kokos Daniel | — | (909) 518 1620 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Koll Custom Homes INC | Gregory Scott Koll | — | (951) 225 1065 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Konakis Plumbing | Kyron Seth Konakis | — | (623) 853 6090 | Other | Murrieta · Riverside County | — | — |
| Konikow Electric INC | William David Konikow | — | (951) 907 7156 | Electricians | Riverside · Riverside County | — | — |
| Kont1go Construction | Oscar Jafet Reyes | — | (951) 227 2200 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Kontiki Construction Services | John Heinave Mafua | — | (951) 447 3301 | GC, remodel, ADU | Murrieta · Riverside County | — | — |
| Kool - White INC | Paul Barry Jr Eldridge | — | (800) 884 7880 | Other roofers | Temecula · Riverside County | — | — |
| Kool Concepts INC | Amrit Bir Ghumman | — | (916) 880 6036 | HVAC | Corona · Riverside County | — | — |
| Koolfog INC | Bryan Harmon Roe | — | (760) 321 9203 | Other | Thousand Palms · Riverside County | — | — |
| Kopal Construction INC | Antonio Burgos | — | (562) 552 1978 | GC, remodel, ADU | Moreno Valley · Riverside County | — | — |
| Kozins | Michael Hector Urteaga | — | (760) 851 8790 | Windows, patio, painters | Palm Desert · Riverside County | — | — |