| M F M Construction | Mclain Frederick Miller | — | (805) 234 7418 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| M G Cottriel | M G Cottriel | — | (805) 235 6484 | GC, remodel, ADU | Templeton · San Luis Obispo County | — | — |
| M J Molnar Trucking & Construction INC | Michael John Molnar | — | (805) 239 5845 | GC, remodel, ADU | Paso Robles · San Luis Obispo County | — | — |
| M J Welding And Fabrication | Matthew Ivan Jmaev | — | (805) 237 2923 | Other | Paso Robles · San Luis Obispo County | — | — |
| M K W Construction | Mark Kenneth Waechtler | — | (805) 471 8279 | GC, remodel, ADU | Cambria · San Luis Obispo County | — | — |
| M L Construction | Neal Allen Macomber | hello@mlconstruction.com | (805) 459 3018 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| M L Entry Gates | M L Entry Gates | mlentrygate@gmail.com | (805) 295 9128 | Other | Shell Beach · San Luis Obispo County | — | — |
| M Niggle | M Niggle | — | (805) 235 1890 | Other | Arroyo Grande · San Luis Obispo County | — | — |
| M S Brown Synthetic Surface Repair | Mark Stewart Jr Brown | — | (805) 249 0723 | Other | Oceano · San Luis Obispo County | — | — |
| M T C Electric | Mark Todd Comins | — | (805) 748 5033 | Electricians | Arroyo Grande · San Luis Obispo County | — | — |
| M T M Construction | Carol Elaine Mc Nellis | — | (805) 835 2097 | GC, remodel, ADU | Paso Robles · San Luis Obispo County | — | — |
| M T S Painting | M T S Painting | — | (530) 386 5565 | Windows, patio, painters | Paso Robles · San Luis Obispo County | — | — |
| M W Construction | Mark Louis Wijsen | — | (510) 504 5760 | GC, remodel, ADU | Cayucos · San Luis Obispo County | — | — |
| M West Coast Construction | Manzano Vincent | — | (805) 703 3530 | GC, remodel, ADU | Atascadero · San Luis Obispo County | — | — |
| M Wicks Construction | Randal Mason Wicks | — | (805) 440 3243 | Other | Paso Robles · San Luis Obispo County | — | — |
| M X Construction INC | Tiffany Dawn Amezcua | — | (805) 723 5201 | HVAC | Nipomo · San Luis Obispo County | — | — |
| Mac Elvaine Construction | William Stephen Mac Elvaine | — | (805) 772 3414 | GC, remodel, ADU | Morro Bay · San Luis Obispo County | — | — |
| Mace Security Alarms INC | Scott Lee Mace | info@macesecurityalarms.com | (805) 528 6223 | Electricians | Los Osos · San Luis Obispo County | — | — |
| Macks Canvas And Awning | Macks Canvas And Awning | — | (805) 481 4554 | Other | Oceano · San Luis Obispo County | — | — |
| Macy Electric | Sean Mic Sheets | — | (805) 235 2464 | Electricians | Morro Bay · San Luis Obispo County | — | — |
| Madruga Construction | Edward Joseph Madruga | hello@rfuenzalida.com | (805) 286 8417 | Other | Paso Robles · San Luis Obispo County | — | — |
| Magnum Painting Co | Marina Yvonne Flores | — | (805) 540 0791 | Windows, patio, painters | Pismo Beach · San Luis Obispo County | — | — |
| Mahaffey General Contractor | Mahaffey General Contractor | — | (805) 235 4691 | GC, remodel, ADU | Los Osos · San Luis Obispo County | — | — |
| Mahogany Construction INC | Stephanie Mae Rende | interested@domainmarket.com | (805) 703 3195 | GC, remodel, ADU | Templeton · San Luis Obispo County | — | — |
| Mahoney Construction | Thomas Adam Mahoney | — | (805) 395 1159 | GC, remodel, ADU | Cambria · San Luis Obispo County | — | — |
| Main Street Landscape Company INC | Eric Eldon Briner | grow@mainstreetlandscape.com | (805) 434 0503 | Windows, patio, painters | Templeton · San Luis Obispo County | — | — |
| Maino Construction Company Incorporated | Michaeline Carroll Maino | — | (805) 543 7411 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| Mainstream Electric Services INC | Richard David Reed | — | (626) 255 9210 | Electricians | Atascadero · San Luis Obispo County | — | — |
| Majestic Tile & Flooring INC | Tyler Camden Prince | — | (805) 489 4448 | Other | Grover Beach · San Luis Obispo County | — | — |
| Major League Landscaping | Major League Landscaping | — | (805) 668 0338 | Windows, patio, painters | Grover Beach · San Luis Obispo County | — | — |
| Mak Family Construction | Clay Carter Knight | — | (805) 423 7706 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| Malott Tile & Design | Malott Tile & Design | — | (805) 709 9281 | Other | Arroyo Grande · San Luis Obispo County | — | — |
| Management Trust | Management Trust | — | (805) 544-9093 | Property managers | San Luis Obispo · San Luis Obispo County | — | — |
| Mankins Plumbing | Mankins Plumbing | — | (805) 995 1111 | GC, remodel, ADU | Cayucos · San Luis Obispo County | — | — |
| Mann Pools Service And Repair INC | Scott Kenneth Mann | — | (805) 602 0852 | Pool | Pismo Beach · San Luis Obispo County | — | — |
| Manning Masonry | Manning Masonry | — | (805) 801 9007 | Other | Nipomo · San Luis Obispo County | — | — |
| Manu Forti Construction LLC | Jeremiah Michael Mccaa | — | (206) 877 3933 | GC, remodel, ADU | Arroyo Grande · San Luis Obispo County | — | — |
| Manzanita Construction | Stuart Alan Hawkes | — | (805) 260 2114 | GC, remodel, ADU | Arroyo Grande · San Luis Obispo County | — | — |
| Marble And Granite Resources | Marble And Granite Resources | — | (805) 769 6404 | Other | Paso Robles · San Luis Obispo County | — | — |
| Marc Eisemann The Contractor | Marc Eisemann The Contractor | — | (805) 748 5625 | GC, remodel, ADU | Templeton · San Luis Obispo County | — | — |