| North Cal Restoration & Construction INC | Juan Carlos Jimenez | — | (415) 306 1875 | GC, remodel, ADU | Point Reyes Station · Marin County | — | — |
| North Coast Restoration Ltd | Denis Clark Murphy | info@northcoastrestoration.com | (415) 250 6436 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| North HVAC Services INC | Paul Patrick Ii Burke | — | (415) 845 6910 | HVAC | Corte Madera · Marin County | — | — |
| North Star Building | North Star Building | — | (415) 424 6274 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Northbay Home Construction Solutions INC DBA Northbay Home | Russell Samuel Quinn | — | (510) 672 3657 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Northbay Sidewall Company | David James Busenbark | — | (415) 892 0415 | Windows, patio, painters | Novato · Marin County | — | — |
| Northbay Stone Works INC | Jared Scott Schmidt | — | (415) 898 0200 | Other | Novato · Marin County | — | — |
| Northbay Welding INC | Daniel Robert Haulot | — | (415) 798 1960 | Other | Novato · Marin County | — | — |
| Northern Construction Tile | Hector Jr Garcia | — | (510) 415 7621 | Other | Mill Valley · Marin County | — | — |
| Northern Marin Plumbing | Northern Marin Plumbing | — | (415) 272 0926 | Other | San Rafael · Marin County | — | — |
| Northgate Acoustics INC | Nathan Philip Martino | — | (415) 485 6241 | Other | Novato · Marin County | — | — |
| Northgate Garage Doors INC | Gregory Todd Berlin | info@ngdoors.com | (415) 472 6004 | Other | San Rafael · Marin County | — | — |
| Northgate Plastering INC | Morales Jimenez Jesus | hello@rfuenzalida.com | (415) 577 6406 | Other | Novato · Marin County | — | — |
| Northgate Roofing | Patrick Edward Newman | — | (415) 225 6327 | Other roofers | Novato · Marin County | — | — |
| Northside Plumbing | Northside Plumbing | — | (415) 760 8608 | Other | Fairfax · Marin County | — | — |
| Norwood Construction INC | Jonathan Christopher Fitzgibbon | — | (415) 756 9300 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Nova Albion Electric | Rodrigo Sales Silveira | — | (415) 918 1240 | Electricians | Novato · Marin County | — | — |
| Novato Electric | Henry Clay Thompson | — | (415) 717 6218 | Electricians | Novato · Marin County | — | — |
| Novato Glass INC | Thomas Irons Matthews | novatoglass@gmail.com | (415) 897 5117 | Windows, patio, painters | Novato · Marin County | — | — |
| Novato Kitchens & Baths LLC | Paul Bradford Price | — | (415) 897 8504 | GC, remodel, ADU | Novato · Marin County | — | — |
| Novato Pool Scene INC | Sean Charles Cross | — | (415) 898 7665 | Pool | Novato · Marin County | — | — |
| Novato Tree Service Company | Rodolfo Estuardo Perez Escobar | service@novatotreeservice.com | (415) 301-5388 | Other | Novato · Marin County | — | — |
| Novum Development And Construction INC | Shervin Shoushtary | — | (415) 747 9129 | GC, remodel, ADU | San Anselmo · Marin County | — | — |
| Nr General Builder INC | Milton Urias Diaz Lopez | — | (415) 577 2307 | GC, remodel, ADU | Novato · Marin County | — | — |
| Nute Construction LLC | Brian Edward Nute | — | (415) 254 6108 | Electricians | San Rafael · Marin County | — | — |
| Nyberg Construction | David Gunnar Nyberg | mark@cruxbuilders.com | (415) 342 8449 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| O Mike's Construction Company INC | Oshaghi Massoud | — | (415) 272 5158 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| O'donnell Enterprises INC | Lindsay Paul O'donnell | — | (415) 453 0372 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| O'donovan Builders INC | Denis Cathal O'donovan | — | (415) 318 9437 | GC, remodel, ADU | Larkspur · Marin County | — | — |
| O'neill & Neville Construction INC | Ian Anthony Neville | — | (415) 359 7343 | Electricians | San Rafael · Marin County | — | — |
| O'neill Construction | John Howard O'neill | oneillsusa5@aol.com | (415) 491-4091 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| O'neill Construction INC | Patrick Bernard O'neill | oneillsusa5@aol.com | (415) 491 4091 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| O'rourke Electric | O'rourke Electric | info@orourkeelectric.com | (705) 746-5232 | Electricians | San Rafael · Marin County | — | — |
| O'ward Tile | O'ward Tile | — | (415) 407 1167 | Other | San Geronimo · Marin County | — | — |
| Oak Run Builder | Oak Run Builder | — | (415) 999 9760 | GC, remodel, ADU | Novato · Marin County | — | — |
| Oakleaf Construction | Eugene Vincent Brolly | — | (415) 800 7580 | GC, remodel, ADU | Sausalito · Marin County | — | — |
| Ochoa's Landscaping LLC | Diaz Gonzalo Ochoa | — | (415) 892 2653 | Windows, patio, painters | Novato · Marin County | — | — |
| Old Town Glass INC | John Michael Pope | info@otglass.com | (415) 897 0088 | Windows, patio, painters | Novato · Marin County | — | — |
| Oldknow Construction | Stephen David Oldknow | — | (415) 297 6150 | GC, remodel, ADU | Mill Valley · Marin County | — | — |
| Olympic Landscaping | Olympic Landscaping | — | (415) 250 5980 | GC, remodel, ADU | Novato · Marin County | — | — |