| Ocote Landscaping | Ocote Landscaping | ocotelandscaping20@gmail.com | (669) 200 8710 | Windows, patio, painters | Sunnyvale · Santa Clara County | — | — |
| Octavio Farias Flooring | Octavio Farias Flooring | — | (408) 658 5103 | Other | Gilroy · Santa Clara County | — | — |
| Octo Painting INC | Rivera-garduno Manuel | — | (408) 849 8206 | GC, remodel, ADU | San Martin · Santa Clara County | — | — |
| Odie Landscaping INC | Jose Antonio Estrada Deciga | info@odielandscaping.com | (408) 891 4739 | Windows, patio, painters | Gilroy · Santa Clara County | — | — |
| Odl Construction INC | Joseph Ralph Rodriguez | — | (408) 676-5447 | GC, remodel, ADU | Sunnyvale · Santa Clara County | — | — |
| Odl Painting | Odl Painting | — | (669) 313 0365 | Windows, patio, painters | San Jose · Santa Clara County | — | — |
| Odom Electric INC | Robinson Lee Odom | — | (650) 576 9566 | Electricians | San Jose · Santa Clara County | — | — |
| Odyssey Gc LLC | Ulysses Edgar Renteria | — | (408) 892 2142 | GC, remodel, ADU | San Jose · Santa Clara County | — | — |
| Off Hours Construction INC | Steven Matthew Delgros | micah@micahrich.com | (669) 253 9906 | GC, remodel, ADU | Campbell · Santa Clara County | — | — |
| Off The Wall Painting | Off The Wall Painting | — | (408) 309 2089 | Windows, patio, painters | Morgan Hill · Santa Clara County | — | — |
| Office Automation Group | Michael William Dyer | — | (408) 554 6244 | Other | San Jose · Santa Clara County | — | — |
| Oil Rock LLC | Nicholas George Panos | — | (408) 220 3233 | Other | Morgan Hill · Santa Clara County | — | — |
| Oku Construction | Garett Mitsuo Oku | — | (650) 279 3225 | GC, remodel, ADU | Mountain View · Santa Clara County | — | — |
| Old Bay Landscaping INC | Guzman Perez Andres | — | (408) 849 8713 | Windows, patio, painters | Gilroy · Santa Clara County | — | — |
| Old Bridge Heating And Cooling | Old Bridge Heating And Cooling | — | (408) 259 2585 | HVAC | San Jose · Santa Clara County | — | — |
| Old Oak Electric INC | Galvan Jonathan | jonathan@oldoakelectric.com | (408) 892 6538 | Electricians | San Jose · Santa Clara County | — | — |
| Olguin's Landscaping And Tree Services | Olguin Fernanda | — | (408) 687 1276 | Windows, patio, painters | Morgan Hill · Santa Clara County | — | — |
| Olivares Home Improvement | Olivares Home Improvement | — | (408) 728 0281 | GC, remodel, ADU | San Martin · Santa Clara County | — | — |
| Olive Garage Doors | Olive Garage Doors | info@olivegaragedoors.com | (888) 403 6161 | Other | Milpitas · Santa Clara County | — | — |
| Oliveira Fence INC | Lisuarte Brasil Avila | — | (408) 727 2617 | Other | Santa Clara · Santa Clara County | — | — |
| Olivera Pool Services | Angel Uzziel Olivera Cortes | — | (408) 761 5781 | Pool | San Jose · Santa Clara County | — | — |
| Ollo Design & Build INC | Eunkee Min | — | (650) 374 7522 | GC, remodel, ADU | Palo Alto · Santa Clara County | — | — |
| Olson Marble & Stone Care INC | Scott Duane Thomas | — | (408) 813 3888 | Other | San Jose · Santa Clara County | — | — |
| Olympic Painting | Olympic Painting | — | (408) 590 6478 | Windows, patio, painters | San Jose · Santa Clara County | — | — |
| Olympic Pool Service | Malcolm Andrew Black | — | (408) 234 1739 | Pool | San Jose · Santa Clara County | — | — |
| Omar Garcia | Omar Garcia | — | (408) 466 4541 | Other | San Jose · Santa Clara County | — | — |
| Omega Power Group INC | Betossib Ron | — | (408) 569 9035 | Electricians | San Jose · Santa Clara County | — | — |
| Omega2 Builders INC | Daniel Soloman N Shong | — | (510) 493 0555 | GC, remodel, ADU | Los Altos · Santa Clara County | — | — |
| Omerovic Cabinet Shop | Omerovic Cabinet Shop | — | (408) 355 3217 | Other | San Jose · Santa Clara County | — | — |
| Omni Sheet Metal INC | Darren Scott Longworth | — | (408) 435 5020 | GC, remodel, ADU | San Jose · Santa Clara County | — | — |
| Omr Commercial Seating & Hospitality INC | Arizmendi Filiberto Vera | — | (408) 977 1615 | Other | San Jose · Santa Clara County | — | — |
| On - Site Construction INC | Jason Richard Cathy | — | (408) 866 8014 | GC, remodel, ADU | San Jose · Santa Clara County | — | — |
| On - Site Electric | Cisic Muhamed | — | (408) 482 5276 | Electricians | San Jose · Santa Clara County | — | — |
| On Design & Remodeling INC | Paul David Estevez | — | (800) 446 8848 | GC, remodel, ADU | San Jose · Santa Clara County | — | — |
| On N Off Electric INC | Hee Yong Jeong | — | (408) 888 9141 | HVAC | Sunnyvale · Santa Clara County | — | — |
| On The Line Painting | On The Line Painting | — | (818) 284 3208 | Windows, patio, painters | San Jose · Santa Clara County | — | — |
| On Time Commercial Doorways INC | Oswaldo Cervantes | — | (510) 931 0506 | Other | San Jose · Santa Clara County | — | — |
| On Time Construction | Robert Scott Handlon | — | (408) 947 8949 | GC, remodel, ADU | San Jose · Santa Clara County | — | — |
| On Time Plumbing | On Time Plumbing | — | (650) 793 0084 | Other | Mountain View · Santa Clara County | — | — |
| Oncall Rooter INC | Orozco Jose Diaz | — | (408) 702 8818 | Other | Sunnyvale · Santa Clara County | — | — |