| Action Fire Protection | Craig Joseph Durand | — | (714) 260 0101 | Other | Los Alamitos · Orange County | — | — |
| Action Glass | Action Glass | — | (714) 847 1535 | Windows, patio, painters | Huntington Beach · Orange County | — | — |
| Action Home Pros INC | John Richard Jr Wilson | info@actionhomepros.com | (714) 670 0828 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| Action Painting Construction | Wayne Keith Johnston | — | (949) 680 4100 | Windows, patio, painters | Irvine · Orange County | — | — |
| Action Power INC | Danny Everett Carlson | — | (949) 709 8006 | Electricians | Rancho Santa Margarita · Orange County | — | — |
| Action Traffic Safety | Action Traffic Safety | — | (626) 893 0404 | Other | Garden Grove · Orange County | — | — |
| Action Welding Corp | Anthony Emilio Medina | — | (714) 632 8669 | Other | Anaheim · Orange County | — | — |
| Active Air Co | Uriostegui Nicholas | info@active-air.com | (714) 552 0292 | HVAC | Santa Ana · Orange County | — | — |
| Active Contracting INC | Chet Andrew Mazakas | admin@active-contracting.com | (562) 881 6406 | GC, remodel, ADU | Villa Park · Orange County | — | — |
| Active Restoration | Kevin Lee Stout | — | (949) 408 0988 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Active Systems INC | Mark Edward Dagui | — | (949) 240 8255 | Other | Capistrano Beach · Orange County | — | — |
| Acura Custom Shutters INC | William Martin Akers | — | (714) 632 5859 | Other | Anaheim · Orange County | — | — |
| Acute Plumbing | Acute Plumbing | — | (714) 425 1667 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Acute Plumbing Concepts | Acute Plumbing Concepts | — | (949) 922 1627 | Other | Rancho Santa Margarita · Orange County | — | — |
| Ad Contractor | Ad Contractor | — | (714) 342 7791 | GC, remodel, ADU | Placentia · Orange County | — | — |
| Ad Flooring | Alonso Arturo Diaz | — | (714) 486 7220 | Other | Garden Grove · Orange County | — | — |
| Ad Great Construction INC | Donnovin Duy Nguyen | — | (909) 525 5446 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| Ad Manfred | Ad Manfred | — | (617) 201 3362 | GC, remodel, ADU | Laguna Hills · Orange County | — | — |
| Adalberto Chavez Construction Company A Partnership | Ralph David Batsel | — | (714) 260 1813 | GC, remodel, ADU | Fullerton · Orange County | — | — |
| Adam Arellano | Adam Arellano | — | (949) 750 7273 | Windows, patio, painters | Trabuco Canyon · Orange County | — | — |
| Adam Beltran | Adam Beltran | — | (818) 426 7688 | Other | Orange · Orange County | — | — |
| Adam Hunt | Adam Hunt | — | (949) 374 0322 | Other | Laguna Niguel · Orange County | — | — |
| Adam Magie Plumbing | Adam Magie Plumbing | — | (562) 493 2699 | Other | Garden Grove · Orange County | — | — |
| Adam Tancredi | Adam Tancredi | hello@adamtancredi.com | (949) 709 4447 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Adam's Altruistic Flooring | Adam's Altruistic Flooring | — | (949) 444 2432 | Other | San Clemente · Orange County | — | — |
| Adam's Plumbing | Adam's Plumbing | — | (714) 528 0995 | Other | Anaheim · Orange County | — | — |
| Adam's Roofing INC | Adam Carl Thorin | — | (714) 965 0245 | Other roofers | Santa Ana · Orange County | — | — |
| Adame Communications INC | Jesus Murguia Adame | — | (714) 855 8201 | Other | Anaheim · Orange County | — | — |
| Adams & Robinson Enterprises | Duane Wyatt Robinson | — | (714) 596 8642 | HVAC | Huntington Beach · Orange County | — | — |
| Adams Brothers Pool Plastering INC | Kevin Lee Adams | — | (562) 867 7283 | Pool | Garden Grove · Orange County | — | — |
| Adams Construction Services | David Lee Adams | — | (714) 720 3710 | Other | Fountain Valley · Orange County | — | — |
| Adams Demolition INC | Arron Patrick Adams | — | (714) 623 0681 | Other | Seal Beach · Orange County | — | — |
| Adams Gc Construction | Keith Steven Adams | — | (949) 340 4056 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Adams Iron Co INC | Robert John Adams | — | (714) 543 4227 | Other | Santa Ana · Orange County | — | — |
| Adams Pipeline Tapping | Adams Pipeline Tapping | — | (714) 777 1440 | Other | Atwood · Orange County | — | — |
| Adams Remodel | Adams Remodel | — | (714) 281 9007 | GC, remodel, ADU | Orange · Orange County | — | — |
| Adb Construction Group | Alan| Alavizade H Yazd Sayedali Alavi | — | (714) 714 7070 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Adb Electric INC | Armando Daniel Banuelos Soria | — | (714) 310 3717 | Electricians | Orange · Orange County | — | — |
| Adco South Roofing And Waterproofing INC | Andrew Jacob Triphon | — | (714) 543 7663 | Other roofers | Orange · Orange County | — | — |
| Add Ventures | Add Ventures | — | (949) 645 7089 | GC, remodel, ADU | Newport Beach · Orange County | — | — |