| A Frame Building Group INC | Kyle Austin Withnell | info@aframebuildinggroup.com | (949) 503 1802 | GC, remodel, ADU | San Juan Capistrano · Orange County | — | — |
| A G Construction | Gociu Alexandru | — | (310) 200 0408 | GC, remodel, ADU | Fullerton · Orange County | — | — |
| A G Electric | Guadarrama Abel | — | (714) 805 1163 | Electricians | Santa Ana · Orange County | — | — |
| A G Plumbing & Building Contractors INC | Garcia Alejandro | — | (714) 936 0561 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| A G Ramirez Painting | Bustos Agustin Ramirez | — | (951) 544 7563 | Windows, patio, painters | Mission Viejo · Orange County | — | — |
| A G Vinyl Fencing INC | Kristina Harutyunyan | — | (714) 340 0007 | Windows, patio, painters | Anaheim · Orange County | — | — |
| A Glass Company | Gregory Scott Blizzard | — | (714) 345 5458 | Windows, patio, painters | Westminster · Orange County | — | — |
| A Good Sign & Graphics Co | Babak Richard Abedi | — | (714) 444 4466 | Other | Santa Ana · Orange County | — | — |
| A Growing Concern Landscapes INC | Douglas Norman Neal | — | (714) 843 5137 | Windows, patio, painters | Huntington Beach · Orange County | — | — |
| A H Tile Experts INC | Chavez Arturo Hernandez | — | (714) 705 5274 | Other | Orange · Orange County | — | — |
| A Hodgson Construction | Andrew James Hodgson | — | (714) 574 6570 | GC, remodel, ADU | Huntington Beach · Orange County | — | — |
| A Homes LLC | Jose Angel Jr Suarez | — | (323) 678 1684 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| A I A Construction INC | Carl Gregory Halverstadt | — | (949) 903 2170 | GC, remodel, ADU | San Juan Capistrano · Orange County | — | — |
| A I M Electric | Ghazaei Mohammad | — | (310) 294 9100 | Electricians | Orange · Orange County | — | — |
| A I M Fire And Safety | John Jerome Dompke | — | (800) 295 4705 | Electricians | Huntington Beach · Orange County | — | — |
| A I W Engineering | Eduardo Arturo Avalos | — | (888) 341 5714 | Other | Buena Park · Orange County | — | — |
| A J Construction | Jeihani Ali | — | (650) 520 9030 | GC, remodel, ADU | Mission Viejo · Orange County | — | — |
| A J Construction Specialties INC | Michael Salvatore Ajello | ajspecial@sbcglobal.net | (714) 241 9101 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| A J Custom Remodeler | A J Custom Remodeler | ajcustomremodeler@gmail.com | (714) 931 2263 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| A J Electric | Nazar Mohamad Al-jamie | — | (714) 390 1477 | Electricians | Tustin · Orange County | — | — |
| A J Holiday Construction INC | Adam Joshua Holiday | — | (949) 630 8991 | GC, remodel, ADU | Newport Beach · Orange County | — | — |
| A J Kirkwood & Associates INC | Leah Jean Zappia | — | (714) 505 1977 | Electricians | Fullerton · Orange County | — | — |
| A J M Engineering | A J M Engineering | — | (626) 926 0995 | Other | Brea · Orange County | — | — |
| A J Tile And Stone Works | Jaime Angel | — | (714) 615 8487 | Other | Orange · Orange County | — | — |
| A K Best Construction INC | Peter Ki Nam | — | (213) 332 3346 | Electricians | Buena Park · Orange County | — | — |
| A K Electric | Kvesic Ante | — | (714) 726 5819 | Electricians | Fountain Valley · Orange County | — | — |
| A K Electric | Boldizsar Akos | — | (714) 420 5227 | Electricians | Portola Hills · Orange County | — | — |
| A K Garage Door Doctor INC | Alexander Noboru Kawano | — | (310) 904 9425 | Other | Buena Park · Orange County | — | — |
| A L C O M M | Aldo Alfredo Sebastian Ceballos | — | (714) 262 9550 | Other | Placentia · Orange County | — | — |
| A L Contractors INC DBA A L Painting And Decorating | John Curtis Leach | — | (310) 536 9744 | GC, remodel, ADU | Huntington Beach · Orange County | — | — |
| A L E Tile | A L E Tile | — | (949) 793 2525 | Other | Orange · Orange County | — | — |
| A L Vineyard Construction INC | Andrew Lee Vineyard | — | (949) 360 1480 | GC, remodel, ADU | Laguna Hills · Orange County | — | — |
| A L X Company INC | Hernandez Alexander | — | (949) 637 5907 | Electricians | Costa Mesa · Orange County | — | — |
| A L Y Construction | Andre Leon Yung | — | (714) 715 6334 | GC, remodel, ADU | Anaheim Hills · Orange County | — | — |
| A M - P M Remodeling | Nagy/nick Yassa | — | (714) 827 0522 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| A M Electrical | Manafi Attaollah | — | (949) 565 6122 | Electricians | Tustin · Orange County | — | — |
| A M Electrical | Metzger Alexander | — | (714) 931 6980 | Electricians | Lake Forest · Orange County | — | — |
| A M G Construction | Alan Martin Greene | — | (949) 307 9098 | GC, remodel, ADU | Lake Forest · Orange County | — | — |
| A M J Roofing | Venegas Alfredo | — | (714) 204 9783 | Other roofers | Anaheim · Orange County | — | — |
| A M M Airconditioning & Heating INC | Armand Minas Malikian | — | (714) 963 6173 | HVAC | Huntington Beach · Orange County | — | — |