| Jeff Leard | Jeff Leard | — | (707) 252 3226 | Electricians | Napa · Napa County | — | — |
| Jeff Menchaca Fine Woodworking | Jeff Menchaca Fine Woodworking | jeff@jeffmenchaca.com | (707) 287 0016 | Other | Napa · Napa County | — | — |
| Jeffrey A Berger DBA Modern Renovations | Modern Renovations | — | (707) 326 8754 | GC, remodel, ADU | Napa · Napa County | — | — |
| Jeffrey Construction | Jeffrey Lee Rhodes | — | (707) 363 6123 | GC, remodel, ADU | Angwin · Napa County | — | — |
| Jensen Works | Jensen Works | — | (403) 869-7791 | GC, remodel, ADU | Napa · Napa County | — | — |
| Jensen's Ornamental INC | Lance Charles Stafford | office@jensensornamental.com | (707) 252 0905 | Electricians | Napa · Napa County | — | — |
| Jeremy Jack INC DBA Standard HVAC | Jeremiah Russell Jack | jeremy@standardhvacnapa.com | (707) 255 1748 | HVAC | Napa · Napa County | — | — |
| Jerome Paints | Jerome Paints | — | (925) 788 8014 | Windows, patio, painters | American Canyon · Napa County | — | — |
| Jesus Gaspar Landscaping | Jesus Gaspar Landscaping | — | (707) 337 7819 | Windows, patio, painters | Napa · Napa County | — | — |
| Jg Masonry LLC | Gonzalez-navarrete Jorge | — | (707) 299 7104 | GC, remodel, ADU | Napa · Napa County | — | — |
| Jim Brock Construction | James Alan Brock | — | (707) 257 3448 | GC, remodel, ADU | Napa · Napa County | — | — |
| Jim Clifton | Jim Clifton | — | (707) 363 4546 | Other | Pope Valley · Napa County | — | — |
| Jitner Painting INC | Lawrence Spencer Jitner | — | (707) 312 9020 | Windows, patio, painters | Yountville · Napa County | — | — |
| Jl Remodeling | Jl Remodeling | — | (707) 738 9198 | GC, remodel, ADU | Napa · Napa County | — | — |
| Jm Access Control | Jm Access Control | — | (707) 312 1783 | Other | Napa · Napa County | — | — |
| Jm Landscaping Service | Maciel Tijero Jesus | — | (707) 975 9503 | Windows, patio, painters | Napa · Napa County | — | — |
| Jmc Valley Construction INC | Juan Manuel Chavez | — | (707) 815 9679 | GC, remodel, ADU | Napa · Napa County | — | — |
| Joe Branum Tree Care INC | Kerry Joe Branum | joebranumtreecare@yahoo.com | (707) 942 8954 | Tree | Calistoga · Napa County | — | — |
| Joe George Construction | Joseph Edwin George | — | (707) 580 6702 | GC, remodel, ADU | Napa · Napa County | — | — |
| Joey Reyes | Joey Reyes | — | (707) 363 1391 | Other | Napa · Napa County | — | — |
| John Collins Door Installations | John Collins Door Installations | — | (707) 815 8294 | Other | Napa · Napa County | — | — |
| John Crystal Pools | John Crystal Pools | — | (310) 477-2828 | Pool | Northridge · Napa County | — | — |
| John Holland Marble & Granite | John Holland Marble & Granite | — | (707) 333 5686 | Other | Yountville · Napa County | — | — |
| John J Crabbe | John J Crabbe | — | (415) 350 2442 | GC, remodel, ADU | Calistoga · Napa County | — | — |
| John L Staggs Landscape Mgt | John L Staggs Landscape Mgt | — | (707) 252 0896 | Windows, patio, painters | Napa · Napa County | — | — |
| John Mendoza Plumbing | John Mendoza Plumbing | info@johnmendozaplumbing.com | (805) 331 6128 | Other | Napa · Napa County | — | — |
| John S Malin | John S Malin | — | (707) 321 0914 | Other | Napa · Napa County | — | — |
| John W Trice Jr | John W Trice Jr | — | (661) 345 4847 | GC, remodel, ADU | Yountville · Napa County | — | — |
| Johnny Gill Electric INC DBA Jg Electric | Johnny Gill | — | (707) 344 8066 | Electricians | Napa · Napa County | — | — |
| Johnson Electrical Technologies | Thomas Bennett Johnson | — | (707) 695 3660 | Electricians | Calistoga · Napa County | — | — |
| Jonathan M Miller | Jonathan M Miller | — | (707) 227 7142 | GC, remodel, ADU | Napa · Napa County | — | — |
| Jordan Mechanical INC | Gary Lee Jordan | — | (707) 260 5110 | HVAC | Napa · Napa County | — | — |
| Jose Pena Plumbing INC | Jose Antonio Pena | — | (707) 337 9736 | Other | Napa · Napa County | — | — |
| Joseph Andrew Walker Iii | Joseph Andrew Walker Iii | — | (707) 365 7241 | Other | Napa · Napa County | — | — |
| Joseph Drosihn Construction | Joseph Frank Iii Drosihn | — | (415) 717 3761 | GC, remodel, ADU | Calistoga · Napa County | — | — |
| Joseph Wiley Electric | Joseph Anthony Wiley | — | (707) 321 3715 | Electricians | Napa · Napa County | — | — |
| Josh Metoxen Electric | Joshua James Metoxen | — | (707) 225 4646 | Electricians | Napa · Napa County | — | — |
| Joshua Parke | Joshua Parke | — | (206) 218 5615 | GC, remodel, ADU | St Helena · Napa County | — | — |
| Joshua Yeager Painting | Joshua Yeager Painting | — | (707) 254 7656 | Windows, patio, painters | Napa · Napa County | — | — |
| Jr&g Construction LLC | Joseph Andrew Rosselli | — | (707) 225 7583 | GC, remodel, ADU | Napa · Napa County | — | — |