| Aoe INC | Francisco Alaman- Chavez | — | (510) 282 9734 | Electricians | Oakland · Alameda County | — | — |
| Ap Plastering INC | Gabriela Yanira Pina | — | (510) 798 1727 | Other | San Lorenzo · Alameda County | — | — |
| Apaz Construction INC | Almas Kenges | — | (925) 290 5661 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Apeiron Electric INC | Jared Enrique Heredia | — | (510) 274 1585 | Electricians | San Lorenzo · Alameda County | — | — |
| Apena Engineering INC | Alejandro Pena | info@apenaengineering.com | (510) 575 2547 | Other | San Leandro · Alameda County | — | — |
| Apex Builders Construction INC | Tran David | — | (510) 999 5979 | Electricians | Union City · Alameda County | — | — |
| Apex Construction General Contractors & Associates Incorporated | William Gil Suoja | — | (510) 317 1484 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Apex General Construction | Trieu Huu Le | — | (510) 882 1941 | GC, remodel, ADU | Piedmont · Alameda County | — | — |
| Apex Interlocking Pavers | Apex Interlocking Pavers | — | (510) 915 2046 | Other | Oakland · Alameda County | — | — |
| Apex Pools | Apex Pools | — | (925) 640 2991 | Pool | Pleasanton · Alameda County | — | — |
| Apex Roofers | Apex Roofers | — | (341) 223-3648 | Other roofers | Alameda · Alameda County | — | — |
| Apex Shield Roofing | Apex Shield Roofing | — | (510) 800-7011 | Other roofers | Alameda · Alameda County | — | — |
| Apple Elevator Company | Lester Joel Appel | — | (510) 839 3147 | Other | Oakland · Alameda County | — | — |
| Apple Heating & Air INC | Benson L Wong | — | (510) 459 8868 | HVAC | San Leandro · Alameda County | — | — |
| Appleberry's Plumbing | Appleberry's Plumbing | — | (415) 738 9944 | Other | Emeryville · Alameda County | — | — |
| Appleby Cleaning & Restoration INC | Joseph Alan Appleby | — | (510) 351 5230 | Restoration | San Leandro · Alameda County | — | — |
| Applied Water Electrical | Nadya Daniela Sanchez | — | (510) 542 0409 | Electricians | Oakland · Alameda County | — | — |
| Applied Waterproofing Systems | Applied Waterproofing Systems | — | (510) 887 8894 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Apricus Construction INC | Eiichi Clifford Hayashi | — | (408) 516 1000 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| Apt Maintenance INC | Keith Russell Berry | — | (510) 747 9713 | GC, remodel, ADU | Emeryville · Alameda County | — | — |
| Aptus Construction | Fernandez Ferrero Eduardo | — | (408) 931 4762 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Aqua Duct Plumbing Contractors | Catherine Ivales Stamatakis | — | (510) 537 4044 | Other | Hayward · Alameda County | — | — |
| Aqua Gunite INC | Jose Gonzalez Aguayo | info@aquagunite.com | (925) 960 9075 | Pool | Livermore · Alameda County | — | — |
| Aqua Sense Fire Protection | Aqua Sense Fire Protection | — | (510) 914 2512 | Other | Alameda · Alameda County | — | — |
| Aqua Stat Plumbing INC | Oscar Sanchez | — | (510) 755 7437 | Other | Hayward · Alameda County | — | — |
| Aquatec Pools | Aquatec Pools | — | (510) 612 1875 | Pool | Fremont · Alameda County | — | — |
| Aquatech Consultancy INC | Reif Hagen Mc Elroy | — | (415) 884 2121 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Ar Innovation Painting | Ar Innovation Painting | arinnovationpainting@gmail.com | (510) 813 7964 | Windows, patio, painters | Oakland · Alameda County | — | — |
| Ar Mcdonald Builders INC | Adrian Roy Mcdonald | — | (510) 860 3810 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Aragon Commercial Landscaping INC | Scott Reid Tabler | — | (408) 998 0600 | Windows, patio, painters | Livermore · Alameda County | — | — |
| Aram Electric INC | Arturo Guillen Ramirez | — | (510) 357 2726 | Electricians | San Leandro · Alameda County | — | — |
| Arana Craftsman Painter | Arana Craftsman Painter | — | (510) 567 9559 | Windows, patio, painters | Oakland · Alameda County | — | — |
| Arandy Painting | Arandy Painting | — | (510) 723 4931 | Windows, patio, painters | Union City · Alameda County | — | — |
| Araujo's Roofing Co | Javier Castaneda Araujo | — | (510) 783 9200 | Other roofers | Hayward · Alameda County | — | — |
| Arbor Md Tree Care INC | Matthew Jeremiah Dickinson | — | (412) 250 2012 | Windows, patio, painters | Pleasanton · Alameda County | — | — |
| Arbor Vision INC | Michael James Waller | — | (925) 409 2979 | Tree | Livermore · Alameda County | — | — |
| Arbor-tech Tree Care INC | Ronald Eugene Carden | — | (510) 881 8733 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Arboricultural Specialties INC DBA The Professional Tree Care Co | Brian Wayne Fenske | — | (888) 335 8733 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| Arborpro Tree Service | Arborpro Tree Service | arborprotreeservicetx@gmail.com | — | Tree | Alameda · Alameda County | — | — |
| Arc Electric | Arce Horacio | — | (510) 967 4493 | Electricians | Oakland · Alameda County | — | — |