| Mendoza Rooter Plumbing | Mendoza Rooter Plumbing | — | (951) 531 5641 | Other | Riverside · Riverside County | — | — |
| Mendozer X Earthworks INC | Miguel Eduardo Mendoza | — | (951) 427 4904 | Other | Riverside · Riverside County | — | — |
| Meneses Pool And Spa INC | Meneses Enrique Soberanes | — | (760) 391 7597 | Pool | Desert Hot Springs · Riverside County | — | — |
| Menifee Drywall | Menifee Drywall | — | (951) 679 3990 | Other | Sun City · Riverside County | — | — |
| Menifee Drywall Construction | Jessie J Lisardo | — | (951) 746 8891 | Other | Menifee · Riverside County | — | — |
| Menifee Landscape | Menifee Landscape | — | (951) 970 0185 | Windows, patio, painters | Menifee · Riverside County | — | — |
| Menifee Roofing Co | Willard Kenneth Jose Picquelle | — | (951) 672 3211 | Other roofers | Temecula · Riverside County | — | — |
| Menifee Valley Air Conditioning INC | Bruce Allen Schuler | — | (951) 471 3414 | HVAC | Hemet · Riverside County | — | — |
| Menifee Valley Electric | Jason Wister Harris | — | (951) 541 8391 | Electricians | Menifee · Riverside County | — | — |
| Menifee Valley Landscape INC | Anthony Martinez | tonymarti1974@gmail.com | (951) 610 9709 | Windows, patio, painters | Menifee · Riverside County | — | — |
| Menifee Valley Plumbing INC | David Andrew Jarboe | — | (951) 309 3429 | Other | Menifee · Riverside County | — | — |
| Menifee Valley Power | Matthew David Richardson | mrichardson@menifeepower.com | (951) 331 6868 | Electricians | Menifee · Riverside County | — | — |
| Menifee Woodshop | Menifee Woodshop | — | (360) 580 8136 | GC, remodel, ADU | Menifee · Riverside County | — | — |
| Mep Construction Services | Joseph Mikhael Labi Abdou | — | (714) 364 7683 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Mer Construction | Manuel Eric Ramos | — | (714) 512 0630 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Mercader Heating Cooling & Ventilation | Mercader Heating Cooling & Ventilation | — | (201) 286 0163 | HVAC | Riverside · Riverside County | — | — |
| Mercado's Manufactured Home Service | Juan Sr Mercado | — | (909) 917 1643 | Other | Riverside · Riverside County | — | — |
| Mercer Construction Co | Tommie Jean Mercer | darren@mercerconstruction.com | (951) 296 0111 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Mercier Electric | James Philip Mercier | — | (909) 528 4543 | Electricians | Calimesa · Riverside County | — | — |
| Merco Earthmoving And Paving | Christian Vladimir Gonzalez | — | (949) 357 6071 | Other | Moreno Valley · Riverside County | — | — |
| Meredith & Simpson Construction Co | Richard Lee Ii Mooty | — | (760) 347 2366 | Electricians | Indio · Riverside County | — | — |
| Merical Electric | Christopher Shaun Hoecker | philb@mericalelectric.com | (951) 433 9765 | Electricians | Wildomar · Riverside County | — | — |
| Meridian Custom Pools INC | Cary Scott Raney | — | (951) 232 5594 | Pool | Wildomar · Riverside County | — | — |
| Meridian Iron INC | Rumen Dobrev | — | (310) 500 0645 | Other | San Jacinto · Riverside County | — | — |
| Merit Electrical Contractors INC | Noah Augustine Rangel | — | (951) 223 5319 | Electricians | Wildomar · Riverside County | — | — |
| Merit Framing INC | Jesse Richard Kimball | — | (951) 719 3206 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Merrilland Enterprises LLC DBA Gal Landscape Management | Kurt Anders Merrill | — | (951) 252 3865 | Windows, patio, painters | Temecula · Riverside County | — | — |
| Merriman's Incorporated | Lisa Kim Merriman | — | (909) 795 5301 | Other roofers | Calimesa · Riverside County | — | — |
| Mesa Fence Co INC | Jason Michael Valenzuela | — | (951) 780 4879 | Other | Perris · Riverside County | — | — |
| Metal Covers | Metal Covers | — | (951) 791 1141 | Other | Hemet · Riverside County | — | — |
| Metal Products Installation By Rock | Metal Products Installation By Rock | — | (760) 262 7727 | Other | Bermuda Dunes · Riverside County | — | — |
| Metal Tech INC | Brian Edward Sr Foley | sales@expromet.com | (951) 301 8975 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Metalrevelations | Walter Karl Gorsuch | — | (760) 347 8846 | Other | Indio · Riverside County | — | — |
| Metcore Concrete Incorporated | Maria Adams Henry | — | (442) 400 3034 | Other | La Quinta · Riverside County | — | — |
| Meterman INC | Randall Shawn Cornelius | — | (951) 672 6909 | Electricians | Menifee · Riverside County | — | — |
| Method Builders | Method Builders | robert@methodbuilders.com | (805) 896-6917 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Metric Heating And Air | Metric Heating And Air | — | (760) 812 0429 | HVAC | Riverside · Riverside County | — | — |
| Metropolitan Concrete Pumping LLC | Osbaldo Gonzalez-Perez | — | (951) 553 8922 | Other | Perris · Riverside County | — | — |
| Metropolitan High Performance Windows | Metropolitan High Performance Windows | — | (951) 215-2200 | Windows, patio, painters | Riverside · Riverside County | — | — |
| Mexcal Fence Company | Jose Sergio Diaz | — | (951) 573 1249 | Other | Riverside · Riverside County | — | — |