| Ariston Heating And Cooling INC | Alexander Menelaos Gailas | — | (925) 421 0888 | HVAC | Pacheco · Contra Costa County | — | — |
| Ark Lock & Key | Ark Lock & Key | — | (925) 776 5397 | Other | Antioch · Contra Costa County | — | — |
| Arla Builders INC | Alex Rafael Leal Arce | — | (510) 804 4093 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Arlie Walker & Sons Painting INC | Kevin Ray Walker | — | (925) 754 8887 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| Arlink Construction INC | Arnelio Sunga Anicete | — | (415) 806 4173 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Arlo Elite Enterprises INC | Ricardo Rodriguez Armenta | — | (925) 505 1418 | Electricians | Brentwood · Contra Costa County | — | — |
| Armandillo Craft Building INC | Garibay Armando Hernandez | — | (925) 446 1219 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Armando Plastering | Armando Plastering | — | (510) 669 9290 | Other | San Pablo · Contra Costa County | — | — |
| Armando Sanchez Construction | Armando De Jesus Sanchez | — | (510) 368 2273 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Armas General Contractor | Armas Torres Eliu | — | (415) 870 0214 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Armendariz Wiring And Communications | Armendariz Wiring And Communications | — | (925) 803 9240 | Other | San Ramon · Contra Costa County | — | — |
| Armenta Landscape Co | Armenta Samuel | — | (925) 481 0609 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| Armor Construction Services INC | Ryan William Leahy | — | (724) 882 4936 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Arms Construction INC | Arezoo Sorkhabi | armsconstructionltd2017@gmail.com | (925) 389 6581 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Arnold Pool/spa Service Repair | Martin Garcia Manalang | — | (925) 825 2575 | Pool | Concord · Contra Costa County | — | — |
| Aron Ambrus Construction | Aron Sandor Ambrus | — | (925) 628 7621 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Aronson Construction | Erik Richard Aronson | — | (925) 337 3110 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Arp Intl INC | Eliyahu Elgrably | — | (510) 375 9383 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Arreola Landscaping & Pool Design | Arreola Landscaping & Pool Design | — | (925) 325 4682 | Windows, patio, painters | Lafayette · Contra Costa County | — | — |
| Arriaga Masonry INC | Francisco Javier Arriaga | — | (510) 978 5998 | Other | Richmond · Contra Costa County | — | — |
| Arriaga Stone Masonry | Arriaga Stone Masonry | — | (510) 932 9629 | Other | Richmond · Contra Costa County | — | — |
| Arrow Finish Carpentry | Aaron Edward Ferguson | aaroncarpentry86@gmail.com | (925) 339 1929 | Other | Antioch · Contra Costa County | — | — |
| Arrow Tile And Stone INC | Arturo Ernesto Rodriguez Hurtado | — | (650) 430 9034 | Other | Antioch · Contra Costa County | — | — |
| Arrowhead Contracting Company | Alfred Kah Chun Lee | — | (925) 989 1453 | Other | Concord · Contra Costa County | — | — |
| Artasola INC | Frank Martin Squaglia | — | (510) 215 8700 | GC, remodel, ADU | El Cerrito · Contra Costa County | — | — |
| Artaville Construction INC | Seyed Akbar Mirjaberi | — | (408) 422 0025 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Artaydi Building | Artemio Guadalupe Ibarra Ledesma | — | (510) 660 8211 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Artbuild Contractor INC | Ricardo Trejo | — | (925) 665 9778 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Artemis Building Co | Lopez Ricardo | info@artemisbuildgroup.com | (925) 765 7049 | Other roofers | Walnut Creek · Contra Costa County | — | — |
| Artes Vivas Landscaping | Artes Vivas Landscaping | — | (925) 497 3627 | Windows, patio, painters | Antioch · Contra Costa County | — | — |
| Artesano Tile | Artesano Tile | — | (628) 236 7604 | Other | San Pablo · Contra Costa County | — | — |
| Artful Tree And Garden | Artful Tree And Garden | — | (510) 495 9713 | Windows, patio, painters | Kensington · Contra Costa County | — | — |
| Arthur Honegger | Arthur Honegger | — | (925) 200 0978 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Arthur L Anderson | Arthur L Anderson | — | (925) 997 2599 | GC, remodel, ADU | Alamo · Contra Costa County | — | — |
| Artisan Home Builders | James Drysdale Granlund | jim@artisanhomebuilders.com | (925) 247 0128 | GC, remodel, ADU | Pacheco · Contra Costa County | — | — |
| Artisan Home Systems | Artisan Home Systems | — | (925) 338 1548 | Other | San Ramon · Contra Costa County | — | — |
| Artistic Landscape | Kristin Michele Gallego | bill.artisticlandscape@gmail.com | (925) 436 0928 | Windows, patio, painters | Knightsen · Contra Costa County | — | — |
| Artistic Metal Works | Artistic Metal Works | — | (510) 439 7720 | Other | San Pablo · Contra Costa County | — | — |
| Arts Painting Solutions | Arts Painting Solutions | — | (925) 516 9607 | Windows, patio, painters | Brentwood · Contra Costa County | — | — |
| Arturos Concrete | Arturos Concrete | — | (925) 759 1540 | Other | Bay Point · Contra Costa County | — | — |