| Alpha Alarm & Audio INC | Loren Asher Dougherty | info@alphaaa.com | (707) 452 8334 | Electricians | Dixon · Solano County | — | — |
| Alpha Bear Home Improvements | Alpha Bear Home Improvements | — | (850) 964 5114 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Alpha Electric | Einstein Alcantara Sambajon | — | (707) 410 4133 | Electricians | Fairfield · Solano County | — | — |
| Alpha Gc Construction INC | Ramiro Cervantes Orozco | — | (707) 720 9556 | GC, remodel, ADU | Vallejo · Solano County | — | — |
| Alpha Paving Construction | Joseph Thomas Jr Lucas | — | (707) 514 5690 | Other | Vacaville · Solano County | — | — |
| Alvar Bay Construction | Alvar Homero Pacheco | — | (415) 845 8323 | GC, remodel, ADU | Suisun City · Solano County | — | — |
| Alvarado Construction | Alvarado Richard | — | (415) 640 6030 | GC, remodel, ADU | Vallejo · Solano County | — | — |
| Alvarez Roofing INC | Alvarez Roofing INC | — | (760) 580-2853 | Other roofers | Escondido · Solano County | — | — |
| Ama Tree | Ama Tree | — | (510) 660 7110 | Other | Vallejo · Solano County | — | — |
| Amador Concrete Solutions | Amador Concrete Solutions | jose@amadorconcretesolutions.com | (707) 720 8842 | Other | Suisun City · Solano County | — | — |
| Ambuild LLC | Saeed Mojarad | — | (916) 769 3265 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| America's Hardwood Floor Corp | Ricardo Javier Appelgren | — | (510) 734 2844 | Other | Fairfield · Solano County | — | — |
| American Air Systems INC | Dana Lynn Rush | — | (650) 339 9354 | HVAC | Vacaville · Solano County | — | — |
| American Asphalt | American Asphalt | — | (530) 665 9222 | Other | Vacaville · Solano County | — | — |
| American Builders Company INC | Alexis Edward Chavez | — | (415) 827 1489 | Electricians | Benicia · Solano County | — | — |
| American Civil Constructors West Coast LLC | Jeffrey Charles Foerste | — | (707) 746 8028 | Other | Benicia · Solano County | — | — |
| American Electrical Contracting | Mark Charles Shontz | — | (707) 301 6597 | Electricians | Vacaville · Solano County | — | — |
| American Plumbing And Trenchless LLC | Joseph John Garin | — | (707) 639 7405 | Other | Vallejo · Solano County | — | — |
| American Window Cover Installations | Jack Fenton Vernasco | — | (707) 434 9700 | Other | Fairfield · Solano County | — | — |
| Americas Roofing | Ortiz Fausto Santos | — | (707) 862 1404 | Other roofers | Vacaville · Solano County | — | — |
| Amg Welding | Jose Miguel Maravilla | — | (707) 592 3108 | Other | Vacaville · Solano County | — | — |
| Amigo Landscape | Amigo Landscape | — | (707) 427 3357 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Amigos Heating And Air | Amigos Heating And Air | — | (707) 427 2785 | HVAC | Fairfield · Solano County | — | — |
| Amos & Sons INC DBA Aaron Plumbing | Robert Alan Amos | — | (707) 678 3333 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Amw Builders INC | Alexander Marc Withers | — | (707) 685 4590 | GC, remodel, ADU | Fairfield · Solano County | — | — |
| Anariba Construction Co | Victor Manuel Anariba | — | (650) 759 4209 | GC, remodel, ADU | Vallejo · Solano County | — | — |
| Anderson Construction | Jeffrey Hawkins Anderson | — | (559) 572 8943 | GC, remodel, ADU | Vacaville · Solano County | — | — |
| Anderson Electric | William Ross Anderson | — | (707) 334 3211 | Electricians | Vallejo · Solano County | — | — |
| Anderson Roofing | Phillip Dean Anderson | — | (707) 321 2625 | Other roofers | Benicia · Solano County | — | — |
| Andre's Air | Andre's Air | — | (707) 386 2313 | HVAC | Vacaville · Solano County | — | — |
| Angel Bros Tree Care | Jesus Antonio Herrera | info@angelbrostreecare.com | (707) 731-7521 | Other | Vallejo · Solano County | — | — |
| Angels Tree Care Corp | Rodolfo Duran Ii De Rosas | — | (707) 344 5597 | Tree | Vallejo · Solano County | — | — |
| Anguiano Electric | Jaime Andres Anguiano | — | (510) 965 8121 | Electricians | Vallejo · Solano County | — | — |
| Angulo Electric | Jose Antonio Angulo | — | (707) 344 6758 | Electricians | Vallejo · Solano County | — | — |
| Anselmo Brothers General Engineering INC | Justin Bernard Anselmo | — | (707) 580 5042 | Other | Dixon · Solano County | — | — |
| Anselmo Distributing | Jody Anne Shamieh-Anselmo | — | (707) 580 5972 | Other | Fairfield · Solano County | — | — |
| Anthony Oreja DBA Suburban Builders | Anthony Oreja DBA Suburban Builders | — | (707) 207 1094 | GC, remodel, ADU | Benicia · Solano County | — | — |
| Anthony Silva Painting | Anthony Silva Painting | — | (707) 592 4202 | Windows, patio, painters | Rio Vista · Solano County | — | — |
| Anthony's Painting | Anthony's Painting | anthony@anthonyspainting.com | (510) 410 8465 | Windows, patio, painters | Fairfield · Solano County | — | — |
| Anton Trenchless System INC | Jose Ascencion Rodriguez | — | (707) 716 6136 | Other | Vacaville · Solano County | — | — |