| Rooter - Tec Plumbing | Rooter - Tec Plumbing | — | (510) 258 3146 | Other | Hayward · Alameda County | — | — |
| Rooter Solutions Of California INC | Mauricio De Jesus| Rodriguez Mauricio Rodriguez | — | (510) 473 5353 | Other | Oakland · Alameda County | — | — |
| Roque Construction | Hugo Ignacio Sr Roque | — | (415) 350 5914 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Roque Drywall LLC | Martin Jesus Roque | — | (510) 813 4162 | Other | Oakland · Alameda County | — | — |
| Rosa Construction INC | Joseph Dean Reil | — | (510) 583 9900 | GC, remodel, ADU | Dublin · Alameda County | — | — |
| Rosales Landscaping Services INC | Rosales Gerardo Montiel | — | (510) 228 8845 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Rosas Brothers Construction | Victor Manuel Rosas | — | (510) 534 1077 | Other | Oakland · Alameda County | — | — |
| Rosas Construction | Victor Manuel Rosas | — | (510) 534 1077 | Other | Oakland · Alameda County | — | — |
| Rosas Construction Company | Rosas Gilberto | — | (510) 318 1372 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Rosas Flooring Co | Francisco Javier Rosas | — | (510) 342 4261 | Other | Oakland · Alameda County | — | — |
| Rosas Remodeling | Rosas Remodeling | — | (510) 610 5228 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Rosenthal Electric | Joshua Dylan Rosenthal | micah@micahrich.com | (510) 712 9298 | Electricians | Berkeley · Alameda County | — | — |
| Roshca Electric Corp | Rodney Shawn Cain | info@roshcaelectric.com | (510) 924 5106 | Electricians | San Leandro · Alameda County | — | — |
| Ross Knazs | Ross Knazs | — | (925) 519 4785 | Windows, patio, painters | Livermore · Alameda County | — | — |
| Ross Mc Donald Company INC | Robert Anthony Schmidt | — | (925) 455 1635 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Rossco Electric | Shawn Curtis Williams | info@indiantypefoundry.com | (510) 332 2335 | Electricians | San Leandro · Alameda County | — | — |
| Route 37 Constructors | Engineering Contractors INC California | — | (925) 461 1500 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Rowe Design Build INC | Eli Jamone Rowe | — | (510) 846 1281 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Roxy Glass INC | Mohammad-Ali Faritous | — | (510) 400 7788 | Windows, patio, painters | Newark · Alameda County | — | — |
| Roy Thomas Construction | Albert Roy Jr Thomas | — | (510) 409 7474 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Roy Trillia | Roy Trillia | — | (510) 524 1352 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Roya Constructora INC | Ramirez Rodolfo Mendoza | — | (510) 809 7880 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Royal Acres Landscaping Corp | Escobedo Juan Hernandez | royalacreslandscaping@gmail.com | (510) 377 6042 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Royal Painting And Decoration | Marcos Antonio Hernandez | — | (510) 540 6578 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| Royal Welding Services INC | Jesus Pedro Barreras Valle | royalweldingservices@yahoo.com | (510) 610 5394 | Other | Oakland · Alameda County | — | — |
| Rp Construction | Retesh Kumar Pal | — | (510) 493 1924 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Rp Sanitation Systems | Pena Ismael Ramos | — | (510) 372 4460 | Other | Oakland · Alameda County | — | — |
| Rq Fencing INC | Raul Jr Quezada | — | (510) 760 1908 | Other | Fremont · Alameda County | — | — |
| Rs Roofing | Kenneth Bradley Holmgren | — | (510) 266 7171 | Other roofers | Fremont · Alameda County | — | — |
| Rsq Construction Services INC | Robert Steve Queirolo | — | (925) 683 1724 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Rts | Ronald Leslie Terpstra | — | (925) 417 8710 | Electricians | Pleasanton · Alameda County | — | — |
| Ruben & Ramon | Ruben Guardado | — | (510) 501 4819 | Other | Newark · Alameda County | — | — |
| Ruby Land Construction | Tun Tun Lin | — | (510) 299 0362 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Rudolph Commercial Interiors INC | Steven Scott Rudolph | — | (510) 601 9191 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Ruffus Robbins & Sons | Ruffus Robbins & Sons | — | (510) 395 0359 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Ruilom Flooring INC | Ruiz Lomeli Silvestre | — | (510) 449 9223 | Other | Fremont · Alameda County | — | — |
| Ruiz Construction | Ruiz Sergio | ruiz@ruiz-construction.com | (510) 684 7074 | GC, remodel, ADU | San Lorenzo · Alameda County | — | — |
| Ruiz Gardening Corp | Gonzalez Adolfo Ruiz | — | (510) 230 7309 | Windows, patio, painters | Oakland · Alameda County | — | — |
| Rumrill Construction | Timothy Lee Rumrill | — | (510) 612 0681 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Rural Pig Management INC | Richard Keith Seever | — | (925) 667 7587 | Other | Castro Valley · Alameda County | — | — |