| Astute Construction INC | Thomas Scott Carr | — | (951) 818 4213 | GC, remodel, ADU | Mira Loma · Riverside County | — | — |
| Asuncion's Custom Stone & Tile | Asuncion's Custom Stone & Tile | — | (562) 253 3020 | Other | Lake Elsinore · Riverside County | — | — |
| Aszendo Concrete | Aszendo Concrete | — | (909) 485 2415 | Other | Jurupa Valley · Riverside County | — | — |
| At Your Command | At Your Command | anapbm@gmail.com | (760) 250 7081 | Windows, patio, painters | Indio · Riverside County | — | — |
| At Your Home Professional Appliance Installations | Tricia Waynette Mora | — | (760) 861 1782 | Other | Indio · Riverside County | — | — |
| Ata Construction Services | Carla Lee Thomas | — | (951) 850 0118 | HVAC | Riverside · Riverside County | — | — |
| Atap Iron Works INC | Ramiro Israel Larios Hernandez | — | (951) 427 6348 | Other | Corona · Riverside County | — | — |
| Aten Construction INC | Adalberto Antonio Saldana | — | (951) 522 0864 | GC, remodel, ADU | Jurupa Valley · Riverside County | — | — |
| Atko Hardwood Floors | Atko Hardwood Floors | — | (310) 962 5721 | Other | Menifee · Riverside County | — | — |
| Atlantic Electric Co | David John Whitman | — | (714) 835 1365 | Electricians | Sun City · Riverside County | — | — |
| Atlantis Pools And Outdoors INC | Jesus Torres | — | (760) 870 8468 | Pool | Bermuda Dunes · Riverside County | — | — |
| Atlantis Stone Care | Efrain Meraz | — | (949) 545 3278 | Other | Corona · Riverside County | — | — |
| Atlas Construction And Remodeling | Alexander Kayden Bowers | — | (951) 348 0341 | GC, remodel, ADU | Murrieta · Riverside County | — | — |
| Atlas Construction Group Services Corp | Louis Jacob Dombrowski | — | (760) 898 0478 | GC, remodel, ADU | Bermuda Dunes · Riverside County | — | — |
| Atom Engineering Construction INC | Tanner R Boyer | — | (951) 766 2806 | GC, remodel, ADU | Hemet · Riverside County | — | — |
| Atomic Ventures | Jose Francisco Arreola | — | (661) 565 3785 | Other | Perris · Riverside County | — | — |
| Atsi | Jay Michael Johnson | — | (760) 738 6804 | Other | Temecula · Riverside County | — | — |
| Attention To Detail Construction LLC | Parra Gabriel Casillas | — | (951) 536 4473 | Other | Winchester · Riverside County | — | — |
| Attention To Detail Painting | Attention To Detail Painting | — | (951) 922 9400 | Windows, patio, painters | Banning · Riverside County | — | — |
| Au Services INC | Armando Urzua | — | (626) 536 8597 | Other | Jurupa Valley · Riverside County | — | — |
| Audio Video Concepts LLC | Gonzalez Emanuel | — | (760) 733 3490 | Other | Palm Desert · Riverside County | — | — |
| Augie Construction And HVAC | Silva Agustin | — | (951) 202 9512 | HVAC | Perris · Riverside County | — | — |
| Augo Site Services | Kathleen Curry Brickley | — | (909) 367 0454 | GC, remodel, ADU | Cherry Valley · Riverside County | — | — |
| August Oak Woodworks INC | Nathan William Rench | — | (951) 375 9274 | Other | Temecula · Riverside County | — | — |
| Aurel Demian Plumbing | Aurel Demian Plumbing | — | (714) 815 2933 | Other | Corona · Riverside County | — | — |
| Ausmus INC | Shawn August Ausmus | firstname@ausmus.com | (909) 649 2065 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Austin & Associates General Contractors | Thomas Philip Austin | — | (951) 371 6705 | GC, remodel, ADU | Norco · Riverside County | — | — |
| Austin's Electrical | Austin Nolan Romero | hello@rfuenzalida.com | (951) 295 9457 | Electricians | Riverside · Riverside County | — | — |
| Austin's HVAC | Austin's HVAC | — | (951) 609 6428 | HVAC | Wildomar · Riverside County | — | — |
| Authentic Landcare | Authentic Landcare | — | (714) 331 0955 | Windows, patio, painters | Corona · Riverside County | — | — |
| Authority Plumbing Heating And Air | Christopher Carter Griffin | — | (714) 485 6031 | HVAC | Corona · Riverside County | — | — |
| Automate Electric INC | Juan Carlos Duenas | — | (323) 947 1099 | Electricians | Norco · Riverside County | — | — |
| Automated Gate Services INC | Steve Montero | — | (208) 344 8379 | Other | Corona · Riverside County | — | — |
| Automatic Electronic Gates | Automatic Electronic Gates | — | (951) 679 4808 | Electricians | Sun City · Riverside County | — | — |
| Automatic Rooter INC | Junior Taeu Chang | — | (951) 305 1467 | Other | San Jacinto · Riverside County | — | — |
| Automation Pride | Kenneth Charles Pride | — | (760) 423 6567 | Other | Palm Desert · Riverside County | — | — |
| Automation Solutions INC | Venegas Sergio | — | (626) 812 4488 | Electricians | Norco · Riverside County | — | — |
| Av Framing INC | Jesus Alberto Valenzuela | — | (714) 805 1188 | Other | San Jacinto · Riverside County | — | — |
| Av Remodeling | Joshua Junior Lopez | — | (951) 575 5201 | GC, remodel, ADU | Hemet · Riverside County | — | — |
| Avaland Contractors | Andres Gonzales Sanchez | — | (714) 865 0824 | GC, remodel, ADU | Riverside · Riverside County | — | — |