| Red & Gold Construction | Ruben Giovanni Hernandez | — | (510) 358 0363 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Red Boot Construction | Richard Douglas James | info@redbootconstruction.com | (510) 534 3616 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Red Door Restoration INC | Safdari Zhobin | reddoorrestoration@yahoo.com | (510) 582 9000 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Red Fox Heating & Cooling | Red Fox Heating & Cooling | — | (510) 926 9479 | HVAC | Oakland · Alameda County | — | — |
| Red Light Fire Alarms INC | Marlon Brandon Vasquez | — | (510) 305 1743 | Electricians | Hayward · Alameda County | — | — |
| Red Plum Studio LLC | Daniel Sebastian Richheimer | daniel@redplumstudio.com | (510) 295 8991 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Red Point Builders | Red Point Builders | — | (415) 497 3311 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Red Star Landscaping | Red Star Landscaping | — | (925) 525 3858 | Windows, patio, painters | Livermore · Alameda County | — | — |
| Red Top Electric Co Emeryville INC | Michael George Curran | — | (925) 667 2900 | Electricians | Livermore · Alameda County | — | — |
| Red Tulip Plumbing | Red Tulip Plumbing | redtulipplumbing@gmail.com | (510) 730 4957 | Other | Fremont · Alameda County | — | — |
| Reddstar Electric Systems Incorporated | Davendran Ananda Reddy | — | (510) 303 9293 | Electricians | Hayward · Alameda County | — | — |
| Redgwick Construction Co | Babak | — | (510) 792 1727 | Other | Oakland · Alameda County | — | — |
| Redline Pavement Solutions INC | Richard Charron Simpson | — | (510) 358 3995 | Other | Fremont · Alameda County | — | — |
| Redo Spaces Construction | Bason Amir | — | (415) 651 0205 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Redux C + D INC | Tyson Richard Schroeder | — | (510) 206 0567 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Redwood Floors | Redwood Floors | — | (415) 661 9315 | Other | Union City · Alameda County | — | — |
| Redwood Grove Build INC | Jack Loring | — | (510) 561 8276 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Redwood Plumbing & Water Heaters | Jesse Allen Torres | — | (925) 895 0446 | Other | Dublin · Alameda County | — | — |
| Reed Brothers Security | Ronald Rajah Reed | — | (510) 505-8025 | Alarm and generators | San Leandro · Alameda County | — | — |
| Reed Plumbing INC | David Arthur Reed | — | (925) 371 5671 | Other | Livermore · Alameda County | — | — |
| Reed's Craftmanship | Reed's Craftmanship | — | (510) 303 6382 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Reel Audio Video INC | Oscar Alberto Ortega | info@reelaudiovideo.com | (510) 677 8330 | Other | San Lorenzo · Alameda County | — | — |
| Reese Construction | Rodney Steven Reese | — | (510) 390 3000 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Regal Remodeling | Regal Remodeling | — | (510) 501 0110 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Regency General Contractors INC | Kwang Hyung Lee | — | (408) 946 7100 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Regevig Roofing | Hugo Cesar Barrios Lopez | sarecorp@regevig4roofs.com | (510) 782 8181 | Other roofers | Hayward · Alameda County | — | — |
| Rei Build Up Construction Corp | Ali Afrasiabi | — | (415) 637 2460 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Reikan | Justin Andrew Delsignore | — | (413) 329 5677 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Reis Construction Company LLC | Richard James Reis | — | (510) 432 9207 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Reiz Builder And Constuction INC | Xiaoxi Zhang | — | (408) 667 5248 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Relentless Electric | Nicholas Everett Martin | — | (925) 577 5628 | Electricians | Livermore · Alameda County | — | — |
| Reliable Concrete | Reliable Concrete | — | (510) 303 3156 | Other | Fremont · Alameda County | — | — |
| Reliable Fire Services LLC | Zubair Ahmed | — | (341) 758 1619 | Other | Fremont · Alameda County | — | — |
| Reliable Raingutter Systems | Reliable Raingutter Systems | — | (925) 828 6117 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| Reliable Stone And Tile Fabricator | Reliable Stone And Tile Fabricator | — | (510) 299 7305 | Other | Hayward · Alameda County | — | — |
| Reliable Tree Experts INC | Brian Wayne Fenske | — | (510) 558 2234 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| Reliance Home Builders | Jack Tapeng Chen | — | (669) 252 4562 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Remedy Building Services LLC | Ryan Matthew Dias | — | (510) 593 5755 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Remodeling | Mohammad Ali Mojaddedi | — | (510) 386 3478 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Remy Powala Construction Corp | Remigiusz Powala | — | (510) 368 2432 | GC, remodel, ADU | San Leandro · Alameda County | — | — |