| M J Hurley Construction | Marc James Hurley | — | (707) 889 8505 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| M J Nelson Construction | Mark James Nelson | — | (707) 292 4702 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| M J P Construction | Michael Joseph Perri | — | (415) 602 7811 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| M J S Construction And Restoration | Matthew John Schmidt | — | (707) 291 8034 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| M K B Construction | Matthew Kenneth Boyrie | — | (707) 669 0164 | GC, remodel, ADU | Cloverdale · Sonoma County | — | — |
| M L Builders | M L Builders | — | (707) 217 5964 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| M L Electric | Lopez Misael | — | (707) 721 7268 | Electricians | Sonoma · Sonoma County | — | — |
| M M Construction | Mynor Estuardo Monterroso Chojolan | — | (415) 261 2252 | Electricians | Cotati · Sonoma County | — | — |
| M M H C INC | Joel La Franz Myles | — | (707) 321 1440 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| M M Miller Construction | Matthew Marshall Miller | mattmillercon@gmail.com | (707) 292 3827 | Tree | Geyserville · Sonoma County | — | — |
| M M Tile | M M Tile | — | (415) 532 9605 | Other | Sonoma · Sonoma County | — | — |
| M Meier & Sons Heating & Air Conditioning INC | Scott David Mc Intosh | — | (707) 537 0197 | HVAC | Santa Rosa · Sonoma County | — | — |
| M P K Construction INC | Timothy Mark Persons | — | (707) 478 4771 | GC, remodel, ADU | Cloverdale · Sonoma County | — | — |
| M P Paving | M P Paving | — | (707) 322 4021 | Other | Santa Rosa · Sonoma County | — | — |
| M R Floors | M R Floors | — | (707) 849 5708 | Other | Santa Rosa · Sonoma County | — | — |
| M Silva Electric INC | Mark Laroy Silva | — | (707) 396 7514 | Electricians | Windsor · Sonoma County | — | — |
| M Stone | M Stone | — | (707) 838 3139 | Windows, patio, painters | Windsor · Sonoma County | — | — |
| M T B | Peter James Mc Goldrick | — | (707) 766 9790 | HVAC | Petaluma · Sonoma County | — | — |
| M T L Systems | M T L Systems | — | (707) 280 4718 | Other | Sebastopol · Sonoma County | — | — |
| M T O Construction | Michael Thomas Orr | — | (707) 887 0210 | GC, remodel, ADU | Forestville · Sonoma County | — | — |
| M V Rook Construction | Michael Victor Rook | — | (707) 481 1194 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| M&e Concrete INC | Troy Stanley Elwood | — | (707) 584 7526 | Other | Rohnert Park · Sonoma County | — | — |
| M's General Construction INC | Oscar Garcia-Membrila | — | (707) 782 8857 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| M2 Builder | M2 Builder | — | (707) 583 5587 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| M29 | Sergey Alexandrovic Shikhalev | — | (757) 892 0640 | GC, remodel, ADU | Graton · Sonoma County | — | — |
| M3 Integrated Services INC | Michael Jonathan Mc Kamey | — | (707) 791 7884 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Mac Donell Construction | Bruce Allen Mac Donell | — | (707) 490 8404 | GC, remodel, ADU | Guerneville · Sonoma County | — | — |
| Mac Landscapes INC | Bryce Wolcott Macmath | — | (707) 478 3874 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Maccario Landscaping | Maccario Landscaping | — | (707) 570 7781 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Machado Bros INC | Craig Anthony Machado | — | (707) 763 7715 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Machado Fine Homes | Machado Fine Homes | — | (707) 799 1845 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Mackalie Susan Felton | Mackalie Susan Felton | — | (707) 326 2589 | Other | Petaluma · Sonoma County | — | — |
| Mackura Handyman Services | Jaeson Pomaikaiokal Mackura | — | (707) 237 3020 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Macquarrie Electrical Services | Craig David Macquarrie | — | (707) 260 4544 | Electricians | Petaluma · Sonoma County | — | — |
| Macquesten Enterprises INC DBA Avavio Construction | Mario Sinik Macquesten | — | (707) 217 7299 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Madcon Builders | Madcon Builders | — | (707) 632 5356 | HVAC | Guerneville · Sonoma County | — | — |
| Maddocks Logging & Construction INC | Robert Leroy Maddocks | — | (707) 823 9575 | Other | Sebastopol · Sonoma County | — | — |
| Maddox Construction | Thomas William Maddox | — | (707) 546 8643 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Madison Electric INC | Erik Lloyd Nordby | — | (707) 579 5257 | Electricians | Santa Rosa · Sonoma County | — | — |
| Madriz Mechanical | Madriz Mechanical | — | (707) 328 4842 | HVAC | Santa Rosa · Sonoma County | — | — |