| Omni Electrical And Design | Donald Basil La Mont | — | (415) 472 5616 | Electricians | Novato · Marin County | — | — |
| One - Stop Construction Group INC | Lisa Miller O'day | — | (415) 464 9400 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| One At A Time Landscape | One At A Time Landscape | — | (415) 961 9141 | Windows, patio, painters | San Rafael · Marin County | — | — |
| One Stop Plastering INC | Kenneth Chapman Breuner | matt@onestopplastering.com | (415) 464 9400 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Ongaro & Sons | Ongaro & Sons | info@ongaroandsons.com | (415) 741-2820 | EV chargers | San Rafael · Marin County | — | — |
| Onspot Welding & Design INC | Christopher Grantley Lago | — | (415) 382 1091 | Other | Novato · Marin County | — | — |
| Orca Construction | Daniel Vincent Murphree | — | (707) 492 2750 | GC, remodel, ADU | Lagunitas · Marin County | — | — |
| Ordonez Construction | Pena-ordonez Santiago | — | (415) 827 8142 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Orellana Painting Solutions | Orellana Painting Solutions | — | (415) 635 8245 | Windows, patio, painters | Novato · Marin County | — | — |
| Organic Garden Services | Alexander Mark Bottmeyer | — | (415) 482 0184 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Original Construction | Charles Thomas Handelin | interested@domainmarket.com | (415) 459 4430 | GC, remodel, ADU | Fairfax · Marin County | — | — |
| Orihuela General Contractor INC | Trujillo Luis Orihuela | — | (415) 535 0365 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Orlandos Landscaping | Orlandos Landscaping | — | (415) 250 3282 | Windows, patio, painters | Novato · Marin County | — | — |
| Ortiz Painting | Ortiz Painting | — | (415) 797 2445 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Ospital Landscape INC | James Peter Ospital | — | (707) 762 6852 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Ostaggi Plumbing INC | Jackson Edward Herrell | — | (415) 453 9254 | Other | San Rafael · Marin County | — | — |
| Out Of The Woods Custom Cabinetry INC | Joseph Matthew Amon | — | (415) 457 0647 | Other | San Rafael · Marin County | — | — |
| Ov Construction Services INC | Osmar Anibal Virula | — | (415) 717 1076 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| P & M Builders INC | Teresa Mariani Nilsen | — | (415) 999 5751 | GC, remodel, ADU | Novato · Marin County | — | — |
| P H Painting | P H Painting | — | (415) 595 7821 | Windows, patio, painters | Novato · Marin County | — | — |
| P L K Construction | Simon Diego Garcia | — | (415) 272 7466 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| P L R Builders INC | Nelson Edwin Richardson | admin@plrbuilders.com | (415) 234 6181 | GC, remodel, ADU | Novato · Marin County | — | — |
| P M Construction | Patrick Lowry Murray | — | (415) 420 2192 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Pac West Painting INC | Brian Paul Beaulieu | abraham@pacwestpainting.com | (415) 516 1411 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Pacific Circle INC | Brandon Rob Stieg | brandon@pacific-circle.com | (415) 785 8044 | GC, remodel, ADU | Lagunitas · Marin County | — | — |
| Pacific Coast Real Estate Inspections | Pacific Coast Real Estate Inspections | — | (415) 516-8110 | Inspectors | Novato · Marin County | — | — |
| Pacific Currents Electric | Paul Christopher Geraghty | — | (415) 302 6979 | Electricians | San Rafael · Marin County | — | — |
| Pacific Garden Artistry Landscaping LLC | Richard Guillemand Sandifer | — | (415) 244 9744 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Pacific Hardscapes | Tyrone Paul Collins | support@pacifichardscapes.com | (415) 918 0089 | Pool | San Rafael · Marin County | — | — |
| Pacific Ridge Construction North INC | Jacob Christopher Glavis | — | (415) 828 0224 | GC, remodel, ADU | Kentfield · Marin County | — | — |
| Pacific Ridge Enterprises INC | Jacob Christopher Glavis | — | (415) 328 6508 | GC, remodel, ADU | Kentfield · Marin County | — | — |
| Pacific Rim Renovations | Pacific Rim Renovations | — | (415) 843 1527 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Pacific Roofing Company | Pacific Roofing Company | sales@pacificroofing.com | (800) 787-3776 | Other roofers | San Rafael · Marin County | — | — |
| Pacific Slope Tree Cooperative INC | Noah James Whitney | — | (415) 663 1300 | Tree | Point Reyes Station · Marin County | — | — |
| Pacific Tradeworks | Pacific Tradeworks | — | (415) 336 1717 | GC, remodel, ADU | San Rafael · Marin County | — | — |
| Pacific Waterproofing | Barba Rivera Javier | — | (415) 367 5715 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Pacifico Construction Co | Panduro Ismael | micah@micahrich.com | (415) 328 1104 | GC, remodel, ADU | Novato · Marin County | — | — |
| Pacificontract | Jacob Richard Weiss | — | (415) 258 9966 | Other | San Rafael · Marin County | — | — |
| Pallavicini Painting | Pallavicini Painting | — | (415) 730 3334 | Windows, patio, painters | San Rafael · Marin County | — | — |
| Palmer & Company Construction | Guy Victor Palmer | — | (415) 518 1551 | GC, remodel, ADU | Mill Valley · Marin County | — | — |