| Apex Electrical LLC | Salvador Jr Alcaraz | — | (707) 332 3832 | Electricians | Napa · Napa County | — | — |
| Aqueduct Plumbing | Aqueduct Plumbing | — | (707) 299 9220 | GC, remodel, ADU | St Helena · Napa County | — | — |
| Areas Painting | Areas Painting | — | (707) 225 1444 | Windows, patio, painters | Napa · Napa County | — | — |
| Associated Building Repair & Maintenance | Associated Building Repair & Maintenance | — | (707) 495 4011 | GC, remodel, ADU | Napa · Napa County | — | — |
| Atlas Peak Construction | Daniel Hugh Iii Mc Lean | — | (707) 254 0751 | Other | Napa · Napa County | — | — |
| Audio House Of Napa | Audio House Of Napa | audiohousesales@gmail.com | (707) 252-1141 | Alarm and generators | Napa · Napa County | — | — |
| Autumn Skies Landscapes | Autumn Skies Landscapes | autumnskieslndscps@sbcglobal.net | (707) 328 1673 | Windows, patio, painters | St Helena · Napa County | — | — |
| Av Plumbing | Av Plumbing | — | (707) 758 6390 | Other | Napa · Napa County | — | — |
| Avelar Hardwood Floors | Avelar Hardwood Floors | — | (707) 252 4946 | Other | Napa · Napa County | — | — |
| Axxa Property Management Inc. | Axxa Property Management Inc. | — | (707) 370-4656 | Property managers | Napa · Napa County | — | — |
| B B I Construction | Brandon Buehler Imhoff | bids@bbiconstruction.com | (707) 312 1118 | GC, remodel, ADU | Napa · Napa County | — | — |
| B Q P Construction | Sok Yung | — | (510) 282 9767 | Electricians | American Canyon · Napa County | — | — |
| B-line Tile & Stone | B-line Tile & Stone | — | (707) 312 0690 | GC, remodel, ADU | Napa · Napa County | — | — |
| Bakker Construction | Robert Frank Bakker | info@bakkerconstruction.com | (707) 480 2674 | GC, remodel, ADU | Napa · Napa County | — | — |
| Balance Pool & Spa | Matthew Lindsey Mcwilliams | — | (707) 252 1415 | Pool | Napa · Napa County | — | — |
| Balcal Construction INC | Maximino Garcia Ballines | info@balcalconstruction.com | (707) 226 2690 | GC, remodel, ADU | Napa · Napa County | — | — |
| Banda Iron Works | Banda Iron Works | — | (707) 224 4457 | Other | Napa · Napa County | — | — |
| Bart Drescher DBA Dp Pipe Works Plumbing | Dp Pipe Works Plumbing | — | (707) 815 2974 | Other | Napa · Napa County | — | — |
| Basford's General Engineering | Basford's General Engineering | — | (707) 337 7858 | Other | Napa · Napa County | — | — |
| Basil Construction INC | Jordan Alexander Fischbach | jordan@basilconstruction.com | (707) 815 9385 | GC, remodel, ADU | Napa · Napa County | — | — |
| Bay Star | Bay Star | — | (510) 301 1219 | Windows, patio, painters | American Canyon · Napa County | — | — |
| Bay Village Builders INC | Justin Corbin La Monte | — | (707) 310 2356 | GC, remodel, ADU | Napa · Napa County | — | — |
| Bazan Landscaping | Bazan Landscaping | bazanlandscaping@yahoo.com | (707) 695 4569 | Windows, patio, painters | Napa · Napa County | — | — |
| Beautiful Again Stone & Tile INC | Genaro Castro Bautista | — | (707) 310 7009 | Other | Napa · Napa County | — | — |
| Bell Construction INC | Joshua Maxwell Bell | joshoua@bellconstruction.com | (707) 738 7770 | GC, remodel, ADU | Napa · Napa County | — | — |
| Bell Products INC | Jeffrey Francis Alcayaga | — | (707) 255 1811 | HVAC | Napa · Napa County | — | — |
| Beltrami Construction | Joseph Michael Beltrami | — | (707) 738 4602 | GC, remodel, ADU | Napa · Napa County | — | — |
| Ben Matthews Painting | Ben Matthews Painting | — | (916) 642 3803 | Windows, patio, painters | Napa · Napa County | — | — |
| Benchmark Civil Construction INC | Joel Charles Gentry | joel@benchmarkcivilconstruction.com | (707) 254 8705 | Other | Napa · Napa County | — | — |
| Benchmark Home Elevator INC | Scott Patrick Britton | — | (707) 255 4687 | Other | Napa · Napa County | — | — |
| Benjamin Beltran Construction | Benjamin Elias Beltran | — | (707) 477 8009 | GC, remodel, ADU | Napa · Napa County | — | — |
| Benson Company INC | Daren Russell Benson | — | (707) 486 8605 | Other | Deer Park · Napa County | — | — |
| Bernal Electric INC | Felipe Alejandro Gonzalez Bernal | — | (707) 815 8281 | Electricians | Napa · Napa County | — | — |
| Bernal's Construction | Flores Bernal Ricardo | — | (707) 666 5429 | GC, remodel, ADU | American Canyon · Napa County | — | — |
| Best Choice Painting Improvements | Best Choice Painting Improvements | — | (619) 886 0306 | Windows, patio, painters | American Canyon · Napa County | — | — |
| Bhm Construction LLC | Jeffery David Mazet | — | (707) 643 4580 | GC, remodel, ADU | Napa · Napa County | — | — |
| Bicknell Builders | Bicknell Builders | — | (707) 363 2362 | GC, remodel, ADU | Napa · Napa County | — | — |
| Bill Johnson Plumbing Co | William Joseph Johnson | — | (415) 505 6747 | Other | American Canyon · Napa County | — | — |
| Bill Nance Construction | Charles William Nance | — | (707) 310 0699 | GC, remodel, ADU | Calistoga · Napa County | — | — |
| Bill Rushby | Bill Rushby | — | (707) 386 4057 | Windows, patio, painters | Napa · Napa County | — | — |