| Jerold Selby Drew | Jerold Selby Drew | — | (707) 272 3403 | Windows, patio, painters | Redwood Valley · Mendocino County | — | — |
| Jerry Beaty's Tree Surgery | Jerry Beaty's Tree Surgery | — | (707) 964 5038 | Tree | Fort Bragg · Mendocino County | — | — |
| Jess Construction | Dana Lee Jess | — | (707) 961 0620 | Other roofers | Fort Bragg · Mendocino County | — | — |
| Jesse J Ellis | Jesse J Ellis | — | (707) 357 1974 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Jh Woodwork | Jh Woodwork | — | (707) 397 5834 | Other | Fort Bragg · Mendocino County | — | — |
| Jk Construction | James Cody Kishbaugh | jk@jkconstruction.com | (707) 357 4208 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Jl Construction | John Fredrick Laberdie | — | (707) 272 5650 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| Jm Electric | Barragan Medina Jesus | — | (707) 684 0703 | Electricians | Gualala · Mendocino County | — | — |
| Jo Ann Henrie | Jo Ann Henrie | — | (707) 489 0647 | GC, remodel, ADU | Talmage · Mendocino County | — | — |
| Joe Turnbow Painting | Joe Turnbow Painting | — | (707) 972 1899 | Windows, patio, painters | Ukiah · Mendocino County | — | — |
| Joe W Sanchez Construction INC | Joseph Wade Sanchez | — | (707) 489 5274 | GC, remodel, ADU | Redwood Valley · Mendocino County | — | — |
| Joel Vidal Painting | Joel Vidal Painting | — | (707) 357 0813 | Other roofers | Fort Bragg · Mendocino County | — | — |
| John Chan Plumbing INC | John Owyoung Chan | — | (707) 272 3583 | Other | Ukiah · Mendocino County | — | — |
| John H Bower INC | John Henry Bower | — | (707) 884 3579 | Tree | Gualala · Mendocino County | — | — |
| John Loomis Construction & Concrete Company | John Anthony Loomis | — | (707) 964 2177 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| John Reynolds Painting | John Robert Reynolds | — | (831) 277 6691 | Windows, patio, painters | Hopland · Mendocino County | — | — |
| John Ruczak Refrigeration | John Ruczak Refrigeration | — | (707) 357 1658 | HVAC | Fort Bragg · Mendocino County | — | — |
| John V Richards | John V Richards | — | (707) 367 2053 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| John Yoder | John Yoder | — | (707) 478 5368 | GC, remodel, ADU | Hopland · Mendocino County | — | — |
| Johnson Brothers Construction | Eric Lynn Johnson | — | (707) 621 3949 | GC, remodel, ADU | Potter Valley · Mendocino County | — | — |
| Johnson Builder | Johnson Builder | — | (707) 489 1816 | GC, remodel, ADU | Boonville · Mendocino County | — | — |
| Johnson Electric & Alarms | Bradley Wyatt Johnson | — | (707) 495 7158 | Electricians | Willits · Mendocino County | — | — |
| Johnson's Construction | Theodore Charles Johnson | — | (707) 354 5067 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| Johnson's Custom Landscaping INC | James Arthur Johnson | — | (707) 462 2656 | Windows, patio, painters | Redwood Valley · Mendocino County | — | — |
| Johnsons Quality Tree Care & Logging Co LLC | Kurt D Johnson | — | (707) 462 4185 | Tree | Ukiah · Mendocino County | — | — |
| Joinery And Design Const | Joinery And Design Const | — | (707) 357 1918 | GC, remodel, ADU | Fort Bragg · Mendocino County | — | — |
| Jon Tipton Electric | Jon Allen Tipton | — | (707) 462 8229 | Electricians | Ukiah · Mendocino County | — | — |
| Jonathan Dunn | Jonathan Dunn | — | (707) 409 0444 | Other | Fort Bragg · Mendocino County | — | — |
| Jones Construction | Curtis Coleman Jones | — | (707) 513 8815 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| Joseph A Lekwart | Joseph A Lekwart | — | (707) 972 5201 | GC, remodel, ADU | Redwood Valley · Mendocino County | — | — |
| Joseph C Thomas | Joseph C Thomas | — | (707) 367 3296 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| Josephs Cabinets | Josephs Cabinets | — | (707) 937 1231 | Other | Mendocino · Mendocino County | — | — |
| Jp Plumbing Services INC | Partida Jonathan | — | (707) 684 0355 | Other | Ukiah · Mendocino County | — | — |
| Js Construction | Jesse Michael Schreiner | — | (707) 621 2418 | GC, remodel, ADU | Ukiah · Mendocino County | — | — |
| Juan Martinez Construction | Juan Manuel Martinez | — | (707) 380 7222 | GC, remodel, ADU | Willits · Mendocino County | — | — |
| Jungle Jim Floors | Jungle Jim Floors | — | (707) 961 0408 | Other | Fort Bragg · Mendocino County | — | — |
| K & S Building & Design | Michael Patrick Ii Keough | — | (707) 391 0495 | GC, remodel, ADU | Redwood Valley · Mendocino County | — | — |
| K & S Meade Construction | Sean Michael Meade | — | (707) 964 4379 | GC, remodel, ADU | Mendocino · Mendocino County | — | — |
| K & T Rising Doors | K & T Rising Doors | — | (707) 462 8489 | Other | Ukiah · Mendocino County | — | — |
| K M Electrical Services | Kevin Anthony Maier | — | (951) 529 6642 | Electricians | Willits · Mendocino County | — | — |