| Mitchell Construction & Development INC | Patricia Ann Mitchell | — | (951) 640 8290 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Mitchell Glazing | Mitchell Glazing | — | (951) 776 6537 | Windows, patio, painters | Riverside · Riverside County | — | — |
| Mitchell Jay Mc Sorley | Mitchell Jay Mc Sorley | — | (909) 238 5928 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Mitercon Construction Corp | Dustin Henry Heister | — | (760) 889 4458 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Mixed Air Conditioned System | Miguel Angel Estrada | — | (951) 231 0968 | HVAC | Perris · Riverside County | — | — |
| Mixtecatl Landscape INC | Pena Gerardo Martinez | — | (951) 220 5854 | Windows, patio, painters | Corona · Riverside County | — | — |
| Mj Painting & Sons INC | Jimenez Martin | — | (760) 902 9338 | Windows, patio, painters | Coachella · Riverside County | — | — |
| Mj Remodel | Mj Remodel | — | (951) 684 4543 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Mj's Tree Service | Joshua Michael Dick | — | (951) 640 3522 | Other | Banning · Riverside County | — | — |
| Mjc Construction | Heung Joon Choo | — | (213) 435 8888 | GC, remodel, ADU | Lake Elsinore · Riverside County | — | — |
| Mjc General Contractor | Mjc General Contractor | — | (951) 805 1921 | GC, remodel, ADU | Perris · Riverside County | — | — |
| Mjn General Construction | Marco Antonio Morales Monjardin | aakashpanchal100@gmail.com | (760) 979 8200 | GC, remodel, ADU | Cathedral City · Riverside County | — | — |
| Mk Fire Protection | Mk Fire Protection | — | (951) 837 0296 | Other | Wildomar · Riverside County | — | — |
| Mk Steelbuilt | Michael J Kleeves | — | (760) 771 7847 | Other | Desert Hot Springs · Riverside County | — | — |
| Mkb Tile | Mkb Tile | — | (949) 275 4737 | Other | Temecula · Riverside County | — | — |
| Mkz Construction INC | Ahrmaan Patrick Williams | ahrmaan@mkz-construction.com | (909) 358 7021 | GC, remodel, ADU | Hemet · Riverside County | — | — |
| Ml Fencing | Luis Antonio Morales | — | (310) 427 5489 | Other | Perris · Riverside County | — | — |
| Mlb Electric Services | Marcus Leroy Brown | — | (323) 228 9664 | Electricians | Indio · Riverside County | — | — |
| Mlc Constructors INC | James Douglas Mc Coy | — | (951) 393 0781 | HVAC | Corona · Riverside County | — | — |
| Mls Concrete Corporation | Serrano Laguna Miguel | — | (760) 272 5623 | Other | Cathedral City · Riverside County | — | — |
| Mm Engineering | Mm Engineering | — | (951) 400 7006 | Other | Lake Elsinore · Riverside County | — | — |
| Mm Garage Doors | Mm Garage Doors | — | (951) 227 0486 | Other | Hemet · Riverside County | — | — |
| Mm Plumbing | Mm Plumbing | — | (760) 501 4983 | Other | Indio · Riverside County | — | — |
| Mmc Construction Company | Modesto Martinez-Cuevas | — | (714) 787 6331 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Mmj Construction INC | Judy Lee| Bailey Judy Lee Bailey-savage | wweeiihhuuaanngg@gmail.com | (951) 216 8862 | HVAC | Temecula · Riverside County | — | — |
| Mmj Flooring LLC | Michael Jr Marquez | — | (760) 660 5091 | Other | Cathedral City · Riverside County | — | — |
| Mmv Electric INC | Miguel Gerardo Viveros | — | (714) 658 9537 | Electricians | Corona · Riverside County | — | — |
| Mn Windows And Glass Doors | Mn Windows And Glass Doors | — | (951) 268 7059 | Windows, patio, painters | Corona · Riverside County | — | — |
| Mno Engineering INC | Mohammad Jamal Abuelkhair | — | (951) 893 8580 | Other | Corona · Riverside County | — | — |
| Mo Pac Enterprises INC | Paul Joseph Moralez | — | (951) 471 8999 | Windows, patio, painters | Wildomar · Riverside County | — | — |
| Mo Power | Mo Power | — | (760) 898 0465 | Electricians | Palm Desert · Riverside County | — | — |
| Moa Painting | Moa Painting | — | (951) 415 8689 | Windows, patio, painters | Eastvale · Riverside County | — | — |
| Mobeta | Michael Kenneth Severino | — | (619) 654 2813 | HVAC | Hemet · Riverside County | — | — |
| Mobile Home Remodel Experts | Dominic Michael Carcioppolo | — | (951) 674 0111 | Other | Lake Elsinore · Riverside County | — | — |
| Mobile Homes Unlimited | Mobile Homes Unlimited | — | (951) 490 7375 | Other | Hemet · Riverside County | — | — |
| Mobile One | Mobile One | — | (760) 863 4812 | Other | Indio · Riverside County | — | — |
| Mobile Screen Shop | Mobile Screen Shop | — | (800) 606 7273 | Other | Perris · Riverside County | — | — |
| Mobile Video Plus | Mobile Video Plus | — | (760) 272 8327 | Other | Menifee · Riverside County | — | — |
| Mobile Video Systems INC | Fred Wayne Reed | — | (951) 805 8668 | Other | Anza · Riverside County | — | — |
| Mocino Construction | David Cristian Mocino-millan | — | (714) 306 7192 | GC, remodel, ADU | Riverside · Riverside County | — | — |