| Bucksworth Construction Services | Colin Patrick Voss | — | (949) 981 5116 | GC, remodel, ADU | Aliso Viejo · Orange County | — | — |
| Bud Remodeling | Bud Remodeling | — | (949) 372 8138 | GC, remodel, ADU | Lake Forest · Orange County | — | — |
| Budget Blinds Of Mission Viejo | Andrew William Ewing | — | (949) 212 9105 | Other | Ladera Ranch · Orange County | — | — |
| Budget Pools | Budget Pools | — | (949) 929 1083 | Pool | Mission Viejo · Orange County | — | — |
| Budget Windows | Budget Windows | — | (949) 284-7227 | Windows, patio, painters | Irvine · Orange County | — | — |
| Budget Windows & Doors LLC | Julio Cesar Radilla Salazar | — | (951) 501 5432 | GC, remodel, ADU | Laguna Beach · Orange County | — | — |
| Buena Vida Asset Management | Buena Vida Asset Management | — | (949) 922 1669 | GC, remodel, ADU | Newport Beach · Orange County | — | — |
| Buena Vista Landscaping | Everardo Carrillo | — | (714) 545 3287 | Windows, patio, painters | Santa Ana · Orange County | — | — |
| Buena Vista Services | Porras Manuel | — | (949) 899 0324 | Other | Anaheim · Orange County | — | — |
| Bueno Group INC | Roland Otto Quintero | — | (562) 569 2191 | Other roofers | La Habra · Orange County | — | — |
| Buffalo Construction | Francisco Javier Alvarez | — | (714) 956 8371 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| Buffalo Tj Construction INC | Songwon Ju | — | (714) 732 2133 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| Buford Construction | Andrew Jenkins Iii Buford | — | (714) 721 1556 | GC, remodel, ADU | Orange · Orange County | — | — |
| Bui Hai | Bui Hai | — | (915) 274 8760 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Build A House LLC | Denny Le | — | (714) 936 3811 | GC, remodel, ADU | Fountain Valley · Orange County | — | — |
| Build By Design Construction | Jose Antonio Uribe Munoz | — | (949) 433 7282 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| Build Homes Construction | Brittain Ray Frye | — | (949) 355 2444 | GC, remodel, ADU | Newport Beach · Orange County | — | — |
| Build Master Construction | Dang Lance | — | (626) 554 6606 | Electricians | Anaheim · Orange County | — | — |
| Build Max Construction INC | Alex Qc Thinh | — | (949) 302 2216 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| Buildcraft Construction Services | Ryan Scott Hunt | quotes@buildcraftconstruction.com | (714) 869 8232 | GC, remodel, ADU | Fullerton · Orange County | — | — |
| Buildcrest Construction Corp | Ahmad Jawid Ataee | — | (714) 757 8371 | Other | Irvine · Orange County | — | — |
| Builder 1 Construction INC | Yazdani Mohammad | — | (949) 605 9418 | GC, remodel, ADU | Mission Viejo · Orange County | — | — |
| Builder One Construction | Minapour Ali | — | (310) 488 1755 | GC, remodel, ADU | Laguna Niguel · Orange County | — | — |
| Builder's Choice Painting Services | Shirlene Cathlene Parshall | — | (949) 289 1278 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| Buildernic Corporation | Luigi Louis Dilernia | — | (949) 848 0009 | GC, remodel, ADU | Lake Forest · Orange County | — | — |
| Builders Alliance LLC | Tod Sterling Matthews | — | (702) 468 7634 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Builders Carpet And Drapery INC | Ashley Josh | — | (714) 778 2600 | Other | Placentia · Orange County | — | — |
| Builders Construction Company | Paul Hoon Cho | — | (714) 336 6556 | GC, remodel, ADU | Brea · Orange County | — | — |
| Builders Scaffolding INC | Luis Demetrio Reynoso Cervantes | — | (949) 439 4611 | Other | Anaheim · Orange County | — | — |
| Builderwell | Camilla Tafreshian | admin@builderwell.com | (949) 232 0555 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Building Air Systems | Richard Joseph Jr Bates | richard@buildingairsystems.com | (714) 745 8636 | HVAC | Anaheim · Orange County | — | — |
| Building Aire INC | Osbelia Maria Miles | info@buildingaire.com | (714) 794 9815 | HVAC | Huntington Beach · Orange County | — | — |
| Building And Construction Contractors | Rory Joseph Burchatz | — | (605) 389 3311 | GC, remodel, ADU | Westminster · Orange County | — | — |
| Building Automation Service Co | Maghbouleh Babak | — | (714) 838 4465 | Other | Santa Ana · Orange County | — | — |
| Building Automation Systems Incorporated | David Andrew Sims | — | (714) 240 0359 | HVAC | Costa Mesa · Orange County | — | — |
| Building Consensus | Bill John Rigdon | — | (323) 965 7448 | GC, remodel, ADU | Irvine · Orange County | — | — |
| Building Construction Services | Philip James Bauchiero | interested@domainmarket.com | (626) 975 4560 | GC, remodel, ADU | Orange · Orange County | — | — |
| Building Construction Specialties INC | Gary Deane Brattain | — | (714) 257 7911 | GC, remodel, ADU | Brea · Orange County | — | — |
| Building Dreams | Building Dreams | — | (310) 901 2111 | GC, remodel, ADU | Buena Park · Orange County | — | — |
| Building Enhancement Network INC | Jessica Moonhee Suh | — | (949) 206 0099 | GC, remodel, ADU | Laguna Hills · Orange County | — | — |