| Joe La Come | Joe La Come | — | (415) 258 9408 | Electricians | San Rafael · Marin County | — | — |
| Joe Sanders Construction | Joseph Thomas Sanders | — | (415) 971 1243 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| Joe The Roofer | Joe The Roofer | — | (415) 246 8102 | Other roofers | Novato · Marin County | — | — |
| Johanna Dunning DBA Dekors Custom Shutters & Interiors | Dekors Custom Shutters & Interiors | — | (510) 835 2392 | Other | Tiburon · Marin County | — | — |
| John A Johnson General Contractor | John A Johnson General Contractor | — | (415) 924 5590 | GC, remodel, ADU | Corte Madera · Marin County | — | — |
| John A Young | John A Young | — | (415) 488 4971 | Electricians | Fairfax · Marin County | — | — |
| John B Ferrarone | John B Ferrarone | — | (415) 460 1575 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| John Blickman Construction | John Wilson Blickman | — | (415) 455 2462 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| John Charles Hill | John Charles Hill | — | (415) 215 9188 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| John Clear | John Clear | — | (415) 606 7959 | Other | Novato · Marin County | — | — |
| John Donovan Cabinetry | John Donovan Cabinetry | — | (415) 272 4398 | Other | Sausalito · Marin County | — | — |
| John Frederic Channell | John Frederic Channell | — | (415) 488 9511 | GC, remodel, ADU | Woodacre · Marin County | — | — |
| John Gleason Plumbing INC | Kevin Michael Gingher | service@johngleasonplumbing.com | (415) 898 2867 | Other | Novato · Marin County | — | — |
| John Hart Construction | John Douglas Hart | — | (415) 999 8182 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| John Harte Construction | John Joseph Harte | — | (415) 419 6598 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| John Hickey Construction | Hickey John Cosntruction | — | (415) 897 5875 | GC, remodel, ADU | Novato · Marin County | — | — |
| John Kostelic Construction | John David Kostelic | — | (415) 819 4157 | GC, remodel, ADU | Point Reyes Station · Marin County | — | — |
| John Louis Maggiora | John Louis Maggiora | — | (707) 480 0078 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| John Molloy Painting INC | John Haywood Molloy | — | (415) 454 9555 | Windows, patio, painters | Fairfax · Marin County | — | — |
| John Owens Services Inc. | John Owens Services Inc. | jarrod.johnowensservices@gmail.com | (707) 925-2906 | HVAC | San Rafael · Marin County | — | — |
| John Pope Incorporated | John Edward Pope | — | (415) 497 5948 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| John Triantafyllos | John Triantafyllos | — | (415) 892 7690 | Other | Novato · Marin County | — | — |
| John Whitmarsh | John Whitmarsh | — | (415) 378 6384 | Other | San Anselmo · Marin County | — | — |
| Johnson And Johnson Electric INC | David James Johnson | — | (415) 447 6879 | Electricians | San Rafael · Marin County | — | — |
| Johnson's Tree And Garden Service LLC | Theodore Paul Johnson | — | (415) 456 8125 | Windows, patio, painters | Corte Madera · Marin County | — | — |
| Jon Haller | Jon Haller | — | (415) 898 0611 | Windows, patio, painters | Novato · Marin County | — | — |
| Jonathan A Rauh | Jonathan A Rauh | — | (415) 509 7526 | GC, remodel, ADU | Muir Beach · Marin County | — | — |
| Jonathan B Burns | Jonathan B Burns | — | (415) 272 7751 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jorge Arita | Jorge Arita | — | (415) 960 4412 | GC, remodel, ADU | Tiburon · Marin County | — | — |
| Jorge D Calderon | Jorge D Calderon | — | (415) 497 9285 | Tree | San Rafael · Marin County | — | — |
| Jorge Dombroski | Jorge Dombroski | — | (415) 305 6514 | Windows, patio, painters | Greenbrae · Marin County | — | — |
| Jorge Mc Manus | Jorge Mc Manus | — | (415) 272 8123 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Jose Luis Landscaping INC | Jose Luis Calderon Tecum | — | (415) 902 3830 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Josehart Construction Management INC | Joel Morris Josehart | — | (415) 927 3611 | GC, remodel, ADU | Corte Madera · Marin County | — | — |
| Joseph Wiese Design Construction | Joseph Michael Wiese | — | (415) 999 9241 | Electricians | Mill Valley · Marin County | — | — |
| Joseph Williams Construction | Joseph Allen Williams | — | (415) 246 2748 | Electricians | San Rafael · Marin County | — | — |
| Josh Tyler Young | Josh Tyler Young | — | (707) 696 7839 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jr Solutions INC | Gerzon Ernesto Berganza Fernandez | — | (415) 506 4226 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Js Construction | Jonah Evan Smallwood | — | (415) 858 5629 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jst Builder | Jst Builder | — | (415) 259 9166 | GC, remodel, ADU | Corte Madera · Marin County | — | — |