| J D Construction | James Waters Deetken | — | (415) 847 1021 | Electricians | San Anselmo · Marin County | — | — |
| J F K & Associates - Marble - Granite - Ceramic | Josef Frank Kremlacek | — | (415) 898 8831 | Other | Novato · Marin County | — | — |
| J F O'sullivan Construction | Jeremiah Finbarr O'sullivan | — | (415) 748 0258 | GC, remodel, ADU | Novato · Marin County | — | — |
| J G Bernales Construction | Joaquin Gabriel Bernales | — | (707) 333 1970 | HVAC | San Anselmo · Marin County | — | — |
| J G Lino Construction INC | James George Lino | — | (415) 663 1939 | GC, remodel, ADU | Point Reyes Station · Marin County | — | — |
| J Green Landscape Construction | Jacob Arthur Green | — | (707) 763 6746 | Windows, patio, painters | Novato · Marin County | — | — |
| J Lingo Painting | J Lingo Painting | — | (415) 688 0420 | Windows, patio, painters | Novato · Marin County | — | — |
| J N M Home Service LLC | John Frank Rossi | — | (415) 763 4002 | GC, remodel, ADU | Novato · Marin County | — | — |
| J Orosco - Monjauze | Philippe Bernard Monjauze | — | (415) 269 7946 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| J P Construction | Jay Rand Potter | — | (415) 250 7253 | GC, remodel, ADU | Forest Knolls · Marin County | — | — |
| J Pontes Plumbing INC | Joseph Craig Pontes | — | (415) 897 1717 | Other | Novato · Marin County | — | — |
| J Psaila Construction | Joseph Harris Psaila | — | (415) 858 9308 | Electricians | Novato · Marin County | — | — |
| J Rupert INC | John Anthony Seidler | — | (415) 328 0069 | Windows, patio, painters | Novato · Marin County | — | — |
| J Spix Fine Cabinets INC | Jay William Spix | — | (415) 298 8927 | Other | Sausalito · Marin County | — | — |
| J T G Painting | J T G Painting | — | (415) 898 3545 | Windows, patio, painters | Novato · Marin County | — | — |
| J V Construction | Jeffrey Elmer Vinum | — | (415) 328 2320 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| J W Burman | J W Burman | — | (415) 297 4843 | GC, remodel, ADU | San Geronimo · Marin County | — | — |
| J W Rigney Construction INC | James William Rigney | — | (415) 609 0773 | Electricians | San Rafael · Marin County | — | — |
| J&a Plumbing And Rooter Service INC | Jose Raul Mendoza | — | (415) 493 6830 | Other | Novato · Marin County | — | — |
| Jackovics Enterprises INC | Thomas Peter Jackovics | — | (415) 927 4653 | Electricians | Corte Madera · Marin County | — | — |
| Jacob Construction INC | Michael Andrew Mac Laird | — | (415) 779 8958 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| Jam Construction INC | John Andrew Martin | — | (415) 740 2928 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Jamba Construction INC | Mark Alan Swanson | — | (415) 435 4481 | GC, remodel, ADU | Tiburon · Marin County | — | — |
| James Banducci | James Banducci | — | (415) 272 6377 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| James C Purkey Const | James C Purkey Const | — | (415) 717 5546 | GC, remodel, ADU | Woodacre · Marin County | — | — |
| James Cressa Const | James Cressa Const | — | (415) 717 1149 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| James Douglas Fox | James Douglas Fox | — | (415) 256 1910 | GC, remodel, ADU | Corte Madera · Marin County | — | — |
| James E Martinez | James E Martinez | — | (510) 290 4520 | GC, remodel, ADU | Corte Madera · Marin County | — | — |
| James Flanagan Builder | James Flanagan Builder | — | (415) 720 5472 | GC, remodel, ADU | Novato · Marin County | — | — |
| James Koger | James Koger | — | (415) 686 2762 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| James Leon | James Leon | cmo@jamesleon.com | (415) 846 4312 | Other | Novato · Marin County | — | — |
| James Martin Construction | James Anthony Martin | — | (415) 608 3604 | GC, remodel, ADU | Corte Madera · Marin County | — | — |
| James Reidy Electric | James Jeremiah Reidy | — | (415) 710 5447 | Electricians | San Rafael · Marin County | — | — |
| James Russell Co | James Bernard Russell | — | (415) 497 2576 | Other | San Anselmo · Marin County | — | — |
| James S Clough Enterprises INC DBA Clough Construction | James Scott Clough | — | (415) 444 5554 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| James W Josephs Co | James Walter Josephs | — | (415) 797 9002 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| James Young Fine Homebuilding | James Young Fine Homebuilding | — | (415) 672 2822 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| Jamie Daniel Robertson | Jamie Daniel Robertson | — | (650) 690 0345 | GC, remodel, ADU | Ross · Marin County | — | — |
| Jan O Werner | Jan O Werner | — | (415) 990 9496 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Janet P Gross INC DBA Heritage Landscapes | David Ari Gross | — | (415) 458 8151 | Windows, patio, painters | Novato · Marin County | — | — |