| All-pro Construction | Troy Michael Antinucci | — | (951) 830 6036 | GC, remodel, ADU | Calimesa · Riverside County | — | — |
| All-star Post-tension | Clint Carl Sundeen | — | (951) 734 3344 | Other | Corona · Riverside County | — | — |
| Allan Trettin | Allan Trettin | — | (951) 448 7733 | GC, remodel, ADU | Wildomar · Riverside County | — | — |
| Allbaugh Electrical Services | Jay Andrew Allbaugh | — | (951) 678 8955 | Electricians | Wildomar · Riverside County | — | — |
| Allegiance Construction Services Corporation | Dennis Franklin Feidner | — | (951) 953 2884 | GC, remodel, ADU | Canyon Lake · Riverside County | — | — |
| Allegiance Electric INC | Anthony David Centanni | — | (949) 205 0067 | Electricians | Murrieta · Riverside County | — | — |
| Allegiance Sign | Kenneth William Flora | — | (909) 322 5319 | Other | Corona · Riverside County | — | — |
| Allegiant Electrical | Alexander David Marauri | allegiantelectricalsolutions@outlook.com | (562) 631 2188 | Electricians | Menifee · Riverside County | — | — |
| Allen Electric | Trevor Ryan Allen | — | (951) 847 1415 | Electricians | Corona · Riverside County | — | — |
| Allen Elkins | Allen Elkins | — | (760) 275 2948 | GC, remodel, ADU | Indio · Riverside County | — | — |
| Allen Heating & Air | Allen Heating & Air | — | (951) 658 8285 | HVAC | Hemet · Riverside County | — | — |
| Alliance Construction Enterprises INC | Ariadne Guerra | — | (760) 222 8895 | GC, remodel, ADU | Indio · Riverside County | — | — |
| Alliance Construction Services | Vincent Joseph Faggella | — | (714) 790 3100 | Electricians | Corona · Riverside County | — | — |
| Alliance Electric | Garry Tayari Venable | — | (951) 563 6232 | Electricians | Moreno Valley · Riverside County | — | — |
| Alliance Fire Service | Ronnie Eldon Mc Dowell | — | (951) 526 7125 | Electricians | Corona · Riverside County | — | — |
| Alliance Home Construction INC | Jose De Jesus Torres Garcia | — | (951) 259 7959 | GC, remodel, ADU | Perris · Riverside County | — | — |
| Alliance Protection And Alliance Integration | Ray Daphne | — | (760) 342 8406 | Electricians | Indio · Riverside County | — | — |
| Alliance Protection INC | Daphne Ray | office@allianceprotection.com | (760) 342 8406 | Electricians | Palm Desert · Riverside County | — | — |
| Alliant Global Security Guard Services | Alliant Global Security Guard Services | — | (909) 935-2477 | Alarm and generators | Riverside · Riverside County | — | — |
| Allied Construction Services | Dean Elliott Jr Hoffman | — | (951) 531 9277 | Other | Corona · Riverside County | — | — |
| Allied Drywall | Allied Drywall | info@allied-drywall.com | (951) 757 3508 | GC, remodel, ADU | Winchester · Riverside County | — | — |
| Allied Electric | Ronald Jerry Dinicola | — | (760) 716 4467 | Electricians | Anza · Riverside County | — | — |
| Allied Erosion Specialist INC | James Steven Mayes | — | (951) 766 9126 | GC, remodel, ADU | Hemet · Riverside County | — | — |
| Allied Grading And Paving INC | Harry Stephen George | — | (619) 583 4881 | Other | Winchester · Riverside County | — | — |
| Allied Manufactured Home Construction | Padilla Peter | — | (909) 224 7946 | Other | Sun City · Riverside County | — | — |
| Allied Pros Construction INC | Miguel Angel Ortuno | alliedpros951@gmail.com | (951) 545 2153 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Allied Steel Co INC | Perry Kevin Chapman | — | (951) 241 7000 | Other | Riverside · Riverside County | — | — |
| Allied Striping INC | Cesar Alan Vazquez Lopez | — | (909) 322 1881 | Other | Murrieta · Riverside County | — | — |
| Allied Traffic And Equipment Rentals INC | Michael Paul Sjobom | — | (951) 696 6950 | Other | Murrieta · Riverside County | — | — |
| Allison Air Conditioning And Heating INC | Steven Christopher Allison | — | (951) 736 1101 | HVAC | Corona · Riverside County | — | — |
| Allison Construction | Kevin Leroy Allison | — | (951) 204 2269 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Allmax Painting INC | Jose Juan Rubio Tolentino | — | (442) 268 8242 | Windows, patio, painters | Desert Hot Springs · Riverside County | — | — |
| Alloy Inovations LLC | Cantu Michael | — | (951) 609 6156 | Other | Wildomar · Riverside County | — | — |
| Allright Services INC | Carleen Sue Alvarenga | — | (760) 272 7430 | Other | Palm Springs · Riverside County | — | — |
| Allstar Development Group LLC | Joshua Lee Kester | — | (951) 757 3228 | GC, remodel, ADU | Winchester · Riverside County | — | — |
| Allstate Restoration Management INC | Kenneth Moore Mc Farland | — | (951) 545 5335 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Alltech Electric INC | Daniel Paul Shoemaker | — | (951) 682 6464 | Electricians | Riverside · Riverside County | — | — |
| Almighty Comfort | Elder Giovanni Moran Garcia | — | (951) 206 1547 | HVAC | Beaumont · Riverside County | — | — |
| Almil General Contruction INC | Jose Alfredo Benitez Morales | — | (714) 720 7256 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Alms Underground Construction INC | Douglas Robert Alms | — | (760) 324 1911 | Other | Cathedral City · Riverside County | — | — |