| Addison - Miller INC | Cara Maria Di Masi | — | (310) 663 1683 | GC, remodel, ADU | Orange · Orange County | — | — |
| Addvance Electric | Stefan Isfan Socaci | — | (657) 825 2600 | Electricians | Anaheim · Orange County | — | — |
| Adee Construction | Chen Chun Yen | — | (626) 384 8881 | GC, remodel, ADU | Los Alamitos · Orange County | — | — |
| Adele Construction INC | Frattone Paul | — | (714) 821 0091 | Other roofers | Rancho Santa Margarita · Orange County | — | — |
| Adimpact Corporate Signage | Tang Thomas | — | (714) 247 0011 | Electricians | Tustin · Orange County | — | — |
| Adl Flooring | Alexis Daniel Lazaro Marcelo | — | (714) 837 1694 | Other | Orange · Orange County | — | — |
| Adlr Earthwork And Paving | Adlr Earthwork And Paving | — | (619) 799 6063 | Other | Laguna Hills · Orange County | — | — |
| Admirable Works | Admirable Works | — | (714) 658 4769 | Windows, patio, painters | Garden Grove · Orange County | — | — |
| Admiral Garage Door Service | Robert James Williamson | — | (949) 525 2993 | Other | Laguna Niguel · Orange County | — | — |
| Ado Construction INC | Sun Cha Lee | — | (714) 319 8485 | GC, remodel, ADU | Cypress · Orange County | — | — |
| Adopt A Highway Maintenance Corporation | Peter Brendan Morin | — | (800) 200 0003 | Windows, patio, painters | Costa Mesa · Orange County | — | — |
| Adp Finish Woodwork INC | Diego Ivan Plata Colin | — | (949) 400 1847 | Other | Garden Grove · Orange County | — | — |
| Adrian Colin Miranda | Adrian Colin Miranda | — | (949) 613 1602 | GC, remodel, ADU | Orange · Orange County | — | — |
| Adrian L Martinez | Adrian L Martinez | — | (949) 306 3245 | Electricians | Lake Forest · Orange County | — | — |
| Adrian Mckeever | Adrian Mckeever | — | (949) 812 2232 | Other | Corona Del Mar · Orange County | — | — |
| Adrian Paun Electric | Paun Adrian | — | (949) 903 9287 | Electricians | Corona Del Mar · Orange County | — | — |
| Adrian Plumbing INC | Samarripa Adrian Paredes | — | (714) 884 6322 | Other | Tustin · Orange County | — | — |
| Adrian's Garden Service | Adrian G Garcia | — | (949) 492 0546 | Windows, patio, painters | San Clemente · Orange County | — | — |
| Adriana Orozco | Adriana Orozco | — | (714) 683 6992 | Other | Anaheim Hills · Orange County | — | — |
| Adu Designers & Builders | Basil Fawaz Ammari | — | (949) 279 7410 | GC, remodel, ADU | Brea · Orange County | — | — |
| Adu Factory INC | Nami Marandi | — | (949) 929 1839 | GC, remodel, ADU | Newport Beach · Orange County | — | — |
| Adu Installer | Adu Installer | — | (949) 342 4482 | GC, remodel, ADU | Rancho Santa Margarita · Orange County | — | — |
| Adu-builds LLC | Tiffany Ann Bulowski | — | (949) 241 9044 | GC, remodel, ADU | Tustin · Orange County | — | — |
| Adu-container Construction Company | Dragan Boroja | — | (949) 302 6866 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Adu365 | Gene Randall Hacker | — | (714) 888 2816 | GC, remodel, ADU | Santa Ana · Orange County | — | — |
| Advalue Construction INC | Zhilong Zhou | — | (949) 899 7888 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Advance Fire Protection Co INC | Sergio Orozco | — | (562) 691 0918 | Other | La Habra · Orange County | — | — |
| Advance General Construction INC | Peichin Lee | — | (626) 354 8843 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Advanced Aquatic Technology INC | David Edward Morris | — | (714) 279 8940 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Advanced Builders | Advanced Builders | interested@domainmarket.com | (714) 543 6900 | GC, remodel, ADU | Laguna Niguel · Orange County | — | — |
| Advanced Builders INC | James Frank Schiermeyer | interested@domainmarket.com | (949) 868 1158 | GC, remodel, ADU | Dana Point · Orange County | — | — |
| Advanced Cable & Communications INC | Stephen Hull Corcoran | — | (714) 435 1806 | Other | Huntington Beach · Orange County | — | — |
| Advanced Cleanroom Microclean Corporation | Janet Renee Ford | — | (714) 751 1152 | Other | Santa Ana · Orange County | — | — |
| Advanced Climate Technologies | Johnathan Eugene Payne | — | (714) 738 0180 | HVAC | Fullerton · Orange County | — | — |
| Advanced Construction & Restoration INC | Petru Gaboras | contact@advancedconstructionrestoration.com | (714) 936 3379 | GC, remodel, ADU | Fullerton · Orange County | — | — |
| Advanced Construction Management Group LLC | Arman Vakili | — | (949) 306 2002 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| Advanced Construction Tech LLC | Glenn David Tofani | — | (949) 502 5353 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Advanced Construction Technologies LLC | Dwyer Scott Cole | — | (949) 502 5355 | Electricians | Irvine · Orange County | — | — |
| Advanced Constructors Corp | Randal Herbert Brown | rbsr@advancedconstructors.com | (714) 892 7100 | GC, remodel, ADU | Huntington Beach · Orange County | — | — |
| Advanced Electrical & Lighting INC | Hugo Rodriguez | — | (714) 285 1700 | Electricians | Santa Ana · Orange County | — | — |