| K S H Construction | Kevin Scott Hewitt | hello@kshconstruction.com | (707) 321 7739 | GC, remodel, ADU | Gualala · Mendocino County | — | — |
| Kamstra Construction INC | Christopher Eric Kamstra | — | (707) 964 1200 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Kaser Construction | Anthony Duane Kaser | — | (707) 489 4743 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| Kb Lane Construction | Kevin Robert Lane | — | (707) 236 5477 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Keith M Wilson | Keith M Wilson | — | (650) 867 4943 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Kelley House Museum | Kelley House Museum | — | (707) 937-5791 | Windows, patio, painters | Mendocino · Mendocino County | — | — |
| Kemppe Liquid Gas Corporation | Kimberly Jayne Kemppe | — | (707) 964 4774 | Other | Fort Bragg · Mendocino County | — | — |
| Ken Mc Courtney Cabinetry | Ken Mc Courtney Cabinetry | — | (760) 522 9689 | Other | Willits · Mendocino County | — | — |
| Ken Murray Plumbing | Ken Murray Plumbing | — | (707) 459 2426 | Other | Willits · Mendocino County | — | — |
| Kenneth Elder | Kenneth Elder | — | (785) 477 9884 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Kentson J Cochran | Kentson J Cochran | — | (707) 882 2101 | GC, remodel, ADU | Point Arena · Mendocino County | — | — |
| Keough's Lanscaping INC | Darrin Russell Mc Klem | — | (707) 468 8048 | Windows, patio, painters | Ukiah · Mendocino County | — | — |
| Kgm Glass | Kgm Glass | anapbm@gmail.com | (707) 513 6286 | Windows, patio, painters | Fort Bragg · Mendocino County | — | — |
| Kh Builder | Kh Builder | — | (207) 547 7079 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| Kiel Rosetti INC DBA Rosetti Engineering | Kiel Justin Rosetti | — | (707) 477 7232 | Other | Hopland · Mendocino County | — | — |
| King Contracting | Darryl Lee Bridges | — | (707) 294 8932 | HVAC | Ukiah · Mendocino County | — | — |
| Kirby Construction | Mitchell Edward Kirby | — | (707) 884 3416 | Other roofers | Gualala · Mendocino County | — | — |
| Kishbaugh Construction | Douglas Wayne Kishbaugh | amykishconstruction@gmail.com | (707) 353 0078 | GC, remodel, ADU | Littleriver · Mendocino County | — | — |
| Kyle Thompson Construction INC | Kyle Robert Thompson | — | (707) 391 7679 | Other | Ukiah · Mendocino County | — | — |
| L Clark Construction | Logan Charles Clark | — | (707) 513 0475 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| L D Giacomini Enterprises INC | Michael Lee Giacomini | — | (707) 462 3717 | Other | Ukiah · Mendocino County | — | — |
| L Loucel Construction | Jeffrey Eugene Martinez | — | (415) 309 0928 | GC, remodel, ADU | Point Arena · Mendocino County | — | — |
| L N S Welding & Fabrication | Jerry Theodore Elenniss | — | (707) 459 2320 | Other | Willits · Mendocino County | — | — |
| La Mere's Plumbing | La Mere's Plumbing | — | (707) 671 5320 | Other | Willits · Mendocino County | — | — |
| Lacantina Doors | Lacantina Doors | — | (888) 221-0141 | Windows, patio, painters | Oceanside · Mendocino County | — | — |
| Lance Edward Peterson | Lance Edward Peterson | — | (707) 272 7458 | Other | Ukiah · Mendocino County | — | — |
| Laneco Drilling Incorporated | Lee Orin Howard | — | (707) 489 5581 | Other | Ukiah · Mendocino County | — | — |
| Larkin Construction | David James Jr Larkin | — | (707) 367 2838 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Larkin Fine Furniture And Cabinetry | Larkin Fine Furniture And Cabinetry | — | (707) 367 6276 | Other | Fort Bragg · Mendocino County | — | — |
| Larry Garber | Larry Garber | — | (707) 972 5870 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| Larry M Masterson Ii Refrigeration | Larry M Masterson Ii Refrigeration | — | (707) 813 7336 | HVAC | Fort Bragg · Mendocino County | — | — |
| Larry Wyatt Construction | Larry Dean Wyatt | — | (707) 272 2340 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| Latoof Painting INC | David John Latoof | — | (707) 937 5032 | Windows, patio, painters | Mendocino · Mendocino County | — | — |
| Lavalley Construction | James David Lavalley | james.lavalley@yahoo.com | (707) 391 7434 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| Layne Construction | Robert Aubrey Layne | l.layne@mchsi.com | (707) 489 8150 | GC, remodel, ADU | Calpella · Mendocino County | — | — |
| Lee A Grissom | Lee A Grissom | — | (707) 234 0004 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| Lee Construction | Michael Vance Lee | — | (707) 972 9723 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Lee Howard Construction Company | Alma Jean Howard | — | (707) 462 6944 | Other | Ukiah · Mendocino County | — | — |
| Lee Rider Aquatics | Lee Rider Aquatics | — | (707) 961 1540 | Pool | Fort Bragg · Mendocino County | — | — |
| Lewis Construction | Stephen Charles Lewis | — | (707) 621 3579 | GC, remodel, ADU | Potter Valley · Mendocino County | — | — |