| Alex Apodaca Plumbing | Alex Apodaca Plumbing | — | (805) 704 2577 | Other | Morro Bay · San Luis Obispo County | — | — |
| Alex Brown Mc Lachlan | Alex Brown Mc Lachlan | — | (805) 748 7314 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| Alexander Glotov's Construction | Glotov Alexander | — | (323) 447 2191 | GC, remodel, ADU | Nipomo · San Luis Obispo County | — | — |
| Alexanders Construction & Cabinetry | Timothy Lon Alexander | — | (805) 461 3457 | GC, remodel, ADU | Atascadero · San Luis Obispo County | — | — |
| Alfirevic Construction Architectural Accents | Mark Richard Alfirevic | — | (805) 235 5023 | GC, remodel, ADU | Los Osos · San Luis Obispo County | — | — |
| Alfred Dahl General Contractor INC | Alfred Christian Dahl | — | (805) 478 8008 | GC, remodel, ADU | Nipomo · San Luis Obispo County | — | — |
| Alfredo's Landscape | Alfredo's Landscape | — | (805) 459 1222 | Windows, patio, painters | Atascadero · San Luis Obispo County | — | — |
| All Around Painting | All Around Painting | — | (805) 280 3689 | Windows, patio, painters | Nipomo · San Luis Obispo County | — | — |
| All In One Construction | Dustin Matthew Evans | — | (805) 550 9848 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| All Private Utility Locating INC | Charles Anthony Elisarraras | info@allprivateutilitylocating.com | (805) 610 4043 | Other | Atascadero · San Luis Obispo County | — | — |
| All Seasons Gardening And Landscaping | Wolting Erik | — | (805) 544 5296 | Windows, patio, painters | San Luis Obispo · San Luis Obispo County | — | — |
| All Source Engineering INC | Brandon Cal Owens | — | (805) 249 8543 | GC, remodel, ADU | Nipomo · San Luis Obispo County | — | — |
| All Star Electric Company | Eric Matthew Holzman | — | (805) 772 5747 | Electricians | Morro Bay · San Luis Obispo County | — | — |
| All Star Painting | All Star Painting | — | (805) 440 6736 | Windows, patio, painters | Pismo Beach · San Luis Obispo County | — | — |
| All Star Plumbing | All Star Plumbing | — | (805) 500 3624 | Other | Paso Robles · San Luis Obispo County | — | — |
| All Star Tile | All Star Tile | — | (805) 801 4377 | GC, remodel, ADU | Los Osos · San Luis Obispo County | — | — |
| All Systems Heating And Air INC | Gregory Dean Cockerill | — | (805) 703 3464 | HVAC | Templeton · San Luis Obispo County | — | — |
| All Tech | All Tech | — | (805) 423 7140 | Other | Paso Robles · San Luis Obispo County | — | — |
| All Things Mechanical INC | Scott Richard Tirre | — | (805) 441 1752 | HVAC | Nipomo · San Luis Obispo County | — | — |
| All Under One Roof | All Under One Roof | — | (805) 215-3272 | Other roofers | San Luis Obispo · San Luis Obispo County | — | — |
| All Wall Systems INC | Luis Saul Baro | — | (805) 431 3364 | GC, remodel, ADU | Paso Robles · San Luis Obispo County | — | — |
| All Ways Energy INC | Jan Michael Ratzlaff | — | (805) 310 6155 | Electricians | Santa Margarita · San Luis Obispo County | — | — |
| Allen L Thompson | Allen L Thompson | — | (661) 398 7222 | GC, remodel, ADU | Grover Beach · San Luis Obispo County | — | — |
| Allen's Woodworking | Allen's Woodworking | allenwoodworking2006@gmail.com | (805) 434 1522 | Other | Paso Robles · San Luis Obispo County | — | — |
| Alliance Septic | Brian Matthew Padgett | — | (805) 221 5493 | Other | Paso Robles · San Luis Obispo County | — | — |
| Alltech Services INC | Josh Foster Backlin | info@alltechservices.com | (805) 239 0300 | HVAC | Atascadero · San Luis Obispo County | — | — |
| Alpha And The Omega Plumbing | Alpha And The Omega Plumbing | — | (805) 458 9688 | Other | Nipomo · San Luis Obispo County | — | — |
| Alpha Electrical Service | Kevin Dean Piper | — | (805) 595 2720 | Electricians | Atascadero · San Luis Obispo County | — | — |
| Alpha Fire Unlimited | Diana Carol Rheinisch | — | (805) 541 2324 | Electricians | San Luis Obispo · San Luis Obispo County | — | — |
| Alpha Painting And General Contractors | Jason Coleman Brock | — | (805) 296 2738 | GC, remodel, ADU | Templeton · San Luis Obispo County | — | — |
| Alpha Tile Co | Juan Manuel Jr Aldas Galindo | — | (805) 748 4889 | Other | Los Osos · San Luis Obispo County | — | — |
| Alpine Construction & Remodel | Nick Franklin Shanks | — | (805) 748 4467 | GC, remodel, ADU | Arroyo Grande · San Luis Obispo County | — | — |
| Alpine Refrigeration Heating & Cooling | Kenneth Allen Kirkpatrick | — | (805) 934 1578 | HVAC | Nipomo · San Luis Obispo County | — | — |
| Altamirano Concrete | Altamirano Concrete | — | (805) 550 3309 | Other | Paso Robles · San Luis Obispo County | — | — |
| Alvarado Electric | Alvarado Romero Francisco | — | (805) 975 4579 | Electricians | Paso Robles · San Luis Obispo County | — | — |
| Alvarado's Total Landscape INC | Jacobo Alberto Alvarado | — | (805) 406 3534 | Windows, patio, painters | Grover Beach · San Luis Obispo County | — | — |
| Alvarados Landscaping | Alvarados Landscaping | joseleal5260@gmail.com | (805) 930 5404 | Windows, patio, painters | Grover Beach · San Luis Obispo County | — | — |
| Amaya Building Company | Amaya Erick | — | (805) 704 0819 | GC, remodel, ADU | San Luis Obispo · San Luis Obispo County | — | — |
| America West Expert Witness INC | Daniel Jack Knight | contact@americawestexpertwitnessinc.com | (805) 235 8775 | Electricians | Atascadero · San Luis Obispo County | — | — |
| American Cornerstone Engineering Group INC | Todd Allen Robinson | — | (805) 440 3348 | Other | San Luis Obispo · San Luis Obispo County | — | — |