| Atlas Windows And Doors | Atlas Windows And Doors | — | (949) 891 1350 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Atm Renovations | Atm Renovations | — | (714) 222 4129 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Atom Company | Michael James Beynon | — | (949) 492 7937 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| Atomic Property Services INC | Thomas Arthur Metcalf | — | (949) 289 4394 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Atp Builders INC | Richard David Diaz | — | (949) 863 9099 | GC, remodel, ADU | Newport Beach · Orange County | — | — |
| Atran Electrical Technology | Tran Andrew | — | (714) 610 8124 | Electricians | Placentia · Orange County | — | — |
| Atterholt Construction And Interiors INC | Joseph William Atterholt | — | (714) 996 3200 | GC, remodel, ADU | Placentia · Orange County | — | — |
| Attic Construction Oc | Yahav Caine | — | (714) 888 8838 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Audio Concepts | Justin Michael Worley | info@audio-concepts.com | (480) 907 7095 | Electricians | Anaheim · Orange County | — | — |
| Audio Images | Mark Aaron Ontiveros | — | (714) 258 7238 | Other | Irvine · Orange County | — | — |
| Audio Video Design INC | Ty Edward Meyer | — | (949) 716 1099 | Other | Mission Viejo · Orange County | — | — |
| Audio Video Projects INC | Ivan Ocampo | — | (949) 566 5633 | Other | San Juan Capistrano · Orange County | — | — |
| Audio Video Security Solutions | Anthony Darnell Hicks | — | (800) 299 5964 | Alarm and generators | Anaheim · Orange County | — | — |
| Audio Video Technologies INC | Tuan Minh Nguyen | — | (714) 676 5723 | Other | Yorba Linda · Orange County | — | — |
| Audio Video Today INC | Nathan Joseph Earl | — | (949) 535 0555 | Other | Laguna Hills · Orange County | — | — |
| Audio Visual Innovations | Audio Visual Innovations | — | (562) 458 9012 | Other | Anaheim · Orange County | — | — |
| Audio Visual Now LLC | Kevin Owen Mahkorn | — | (949) 306 4162 | Other | Laguna Hills · Orange County | — | — |
| Audiovisions INC | Theodore A Taylor | — | (949) 206 0606 | Other | Irvine · Orange County | — | — |
| Ault's Pool Service | Richard William Ault | — | (714) 404 7718 | Pool | Huntington Beach · Orange County | — | — |
| Aurelio Meza | Aurelio Meza | — | (323) 376 4776 | GC, remodel, ADU | Orange · Orange County | — | — |
| Aus Build INC | Dean Leslie Daniels | — | (714) 676 7320 | GC, remodel, ADU | Orange · Orange County | — | — |
| Aussie Carpets | Aussie Carpets | — | (949) 887 6166 | Other | Laguna Hills · Orange County | — | — |
| Aussieblue Roofing INC | Mark Stephen Dickson | — | (800) 369 6310 | Other roofers | Orange · Orange County | — | — |
| Austek Construction Services INC | Jaimie Marie Sullivan | — | (808) 464 2348 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| Austin Construction INC | Janet Loraine Austin | — | (714) 543 0238 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Austin Manuel Coelho | Austin Manuel Coelho | — | (714) 310 2577 | Other roofers | Cypress · Orange County | — | — |
| Austin's Building Company | Austin Robert Prian | — | (949) 842 2001 | GC, remodel, ADU | Lake Forest · Orange County | — | — |
| Austin/jones Corp | Enrique Soto Catalan | — | (714) 236 1735 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Authority Plumbing And Rooter INC | Francisco Javier Rojo | — | (714) 319 2375 | Other | Costa Mesa · Orange County | — | — |
| Autobahn Construction INC | John William Korb | — | (714) 769 7025 | Other | Santa Ana · Orange County | — | — |
| Autolift Services INC | Chris Cary Woodson | — | (714) 816 9890 | Other | Los Alamitos · Orange County | — | — |
| Automated Access | Automated Access | — | (714) 263 6400 | Other | Orange · Orange County | — | — |
| Automated Enterprise INC | Jeffrey Richard Elsenpeter | — | (714) 315 3032 | Other | Fullerton · Orange County | — | — |
| Automated General Contracting INC | Douglas John Wischmeyer | — | (714) 797 2810 | Electricians | Huntington Beach · Orange County | — | — |
| Automated Parking Technologies INC | Manuel Antonio Rosas | — | (714) 865 0146 | Other | Anaheim Hills · Orange County | — | — |
| Automatic Openings INC | Mario Martinez | — | (714) 258 7100 | Other | Placentia · Orange County | — | — |
| Automation And Electrical Services INC | Liviu Valentin Popa | — | (714) 856 4447 | Electricians | Fullerton · Orange County | — | — |
| Automation Control Store LLC | Darrel Eugene Hauk | — | (949) 939 0463 | Other | Dana Point · Orange County | — | — |
| Automation Installation Mechanical Electrical INC | Michael Herbert Bartels | — | (909) 234 4447 | Electricians | Huntington Beach · Orange County | — | — |
| Automation Pride | Matthew William Melton | — | (714) 632 8882 | Electricians | Anaheim · Orange County | — | — |