| Jason Clark Painting | Jason Clark Painting | — | (415) 240 8822 | Windows, patio, painters | Novato · Marin County | — | — |
| Jason Mardesich | Jason Mardesich | — | (415) 518 8252 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jason Tunnell Construction | Jason Monroe Tunnell | — | (415) 250 2994 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| Jason Turner | Jason Turner | — | (415) 640 3636 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Javier De Luz Landscaping LLC | Javier De Luz Hernandez | — | (415) 302 0017 | Windows, patio, painters | Novato · Marin County | — | — |
| Jay's Plumbing | Jay's Plumbing | — | (707) 971 1656 | Other | San Rafael · Marin County | — | — |
| Jbk Mechanical INC | Jerry Lee Cruse | — | (415) 456 4149 | Other | San Anselmo · Marin County | — | — |
| Jc Prestige Home Builders LLC | Daniel Hutton Morgan | — | (415) 637 2151 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jcb Construction INC | Josias Usiel Constanza Barrios | — | (510) 942 9290 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jcoso Construction | Justin Daniel Carter | — | (970) 222 8137 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| Jd Woodworks LLC | John David Duysen | — | (415) 717 0333 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| Jeff Casto Construction | Jeffrey Clayton Casto | — | (415) 250 0026 | Electricians | San Rafael · Marin County | — | — |
| Jeff De Leon Painting | Jeff De Leon Painting | — | (415) 883 1902 | Windows, patio, painters | Novato · Marin County | — | — |
| Jeff E Lapic | Jeff E Lapic | — | (415) 710 7171 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jeff Mc Phail Construction & Design INC DBA Jw Phail Construction | Jeffery William Mc Phail | — | (415) 259 8055 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jeff Morgan Electric | Jeffrey Blake Morgan | — | (707) 479 3938 | Electricians | Novato · Marin County | — | — |
| Jeffery Greg Construction INC | Jeffery Greg Thomas | — | (415) 377 3143 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jeffrey James Prewett | Jeffrey James Prewett | — | (310) 756 9644 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| Jeffrey L Francis | Jeffrey L Francis | — | (408) 398 0523 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Jeffrey R Bandettini | Jeffrey R Bandettini | — | (415) 215 5298 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jeffrey S Mercurio DBA Mercurio | Jeffrey S Mercurio DBA Mercurio | — | (415) 883 8375 | Electricians | Novato · Marin County | — | — |
| Jerry Thompson & Sons Painting INC | Christopher George Gaidano | — | (415) 454 1500 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Jesse W Apperson General Contractor | Jesse W Apperson General Contractor | — | (415) 883 6000 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jft Corporation | James Elwyn Fraser | — | (628) 253 7455 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Jim Allen Construction LLC | James Russell Allen | — | (415) 847 2414 | GC, remodel, ADU | Kentfield · Marin County | — | — |
| Jim Hanretty | Jim Hanretty | — | (415) 868 2367 | Other | Stinson Beach · Marin County | — | — |
| Jim Hayes Painting | Jim Hayes Painting | — | (415) 608 1330 | Windows, patio, painters | Novato · Marin County | — | — |
| Jim Jenkins Construction | James Anthony Jenkins | — | (415) 847 5317 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| Jim Santangelo Electrical Contractor | James Joseph Santangelo | — | (510) 367 4842 | Electricians | Novato · Marin County | — | — |
| Jimenez Construction International | Macario Camaja Jimenez | — | (415) 572 3527 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jireh Contractor INC | Gilberto Eulises Vasquez Trinidad | hello@rfuenzalida.com | (415) 879 5933 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jlazor Builder | Jlazor Builder | — | (415) 596 0765 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jll Builders INC | Jeffrey Laurence Langston | jeff@jllbuilders.com | (415) 720 0143 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jm Electric | Javier Andres Miranda Zamora | — | (415) 717 9528 | Electricians | San Rafael · Marin County | — | — |
| Jmag Construction Services INC | Magana Javier | — | (415) 509 5266 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jmc General Construction | Jesus Manuel Castillo Vazquez | — | (415) 595 2341 | GC, remodel, ADU | Novato · Marin County | — | — |
| Jobaro Home Improvement Contractor | Jobaro Home Improvement Contractor | — | (415) 573 9944 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jock H Rystrom Electrical Contractor | Jock H Rystrom | — | (415) 233 1178 | Electricians | Sausalito · Marin County | — | — |
| Joe Chambers Art & Design | Joe Chambers Art & Design | — | (415) 250 1342 | Other | Forest Knolls · Marin County | — | — |
| Joe Fox | Joe Fox | — | (415) 246 1956 | Other | Point Reyes Station · Marin County | — | — |