| Benjamin Franklin Plumbing | Stanley Lewis Kincannon | — | (707) 263 1020 | GC, remodel, ADU | Lakeport · Lake County | — | — |
| Bernard Krahne | Bernard Krahne | — | (707) 231 7686 | Other | Clearlake Oaks · Lake County | — | — |
| Bierly Construction | Thomas Patrick Bierly | — | (925) 207 8351 | GC, remodel, ADU | Kelseyville · Lake County | — | — |
| Big And Little Construction | Larry David Ii Atkins | — | (707) 533 9960 | GC, remodel, ADU | Lower Lake · Lake County | — | — |
| Big Valley Builders | Big Valley Builders | — | (707) 245 6864 | GC, remodel, ADU | Lakeport · Lake County | — | — |
| Big Valley Electric And Service Company | Jeffery Allen Holdener | — | (707) 349 2086 | Electricians | Kelseyville · Lake County | — | — |
| Billy Peacock | Billy Peacock | — | (707) 349 0194 | Windows, patio, painters | Kelseyville · Lake County | — | — |
| Blair Drywall & Painting | Blair Drywall & Painting | — | (707) 263 4404 | Windows, patio, painters | Lakeport · Lake County | — | — |
| Blake's Backhoe Service | Blake Adelbert Fifield | — | (707) 738 2892 | Other | Lakeport · Lake County | — | — |
| Bob Sabatino Construction | Robert Joseph Sabatino | — | (707) 355 0145 | GC, remodel, ADU | Middletown · Lake County | — | — |
| Bobby G's Electric | Lew Robert Giere | — | (707) 245 2737 | Electricians | Lakeport · Lake County | — | — |
| Boggs Lane Woodworks | Boggs Lane Woodworks | boggslane@att.net | (707) 263 1262 | GC, remodel, ADU | Kelseyville · Lake County | — | — |
| Bowlin Construction INC | Charles Michael Bowlin | — | (707) 279 4028 | GC, remodel, ADU | Kelseyville · Lake County | — | — |
| Bravos Construction | George Dean Iii Bravos | — | (925) 212 5288 | GC, remodel, ADU | Clearlake · Lake County | — | — |
| Brian Pr Davis DBA Northern Industrial Construction | Brian Patrick Rile Davis | — | (619) 729 3915 | Other | Kelseyville · Lake County | — | — |
| Bridges Construction | Douglas Keith Bridges | — | (707) 263 4000 | GC, remodel, ADU | Kelseyville · Lake County | — | — |
| Brodnansky Construction | Darin Guy Brodnansky | — | (707) 263 4409 | GC, remodel, ADU | Lakeport · Lake County | — | — |
| Brooks Pest Control | Brooks Pest Control | — | (833) 369-1242 | Pest, tile roofs | Escondido · Lake County | — | — |
| Bruce E St Cyr Gen Eng Contractor | Bruce Eugene St Cyr | — | (707) 489 1439 | Other | Lower Lake · Lake County | — | — |
| Bzzn Landscaping | Bzzn Landscaping | — | (707) 738 9248 | Windows, patio, painters | Hidden Valley Lake · Lake County | — | — |
| C C S Crabtree Communication Solutions | Scott Nathan Crabtree | — | (707) 972 8000 | Other | Kelseyville · Lake County | — | — |
| C K Excavating And Demolition | C K Excavating And Demolition | — | (707) 291 5665 | Other | Middletown · Lake County | — | — |
| C N R Construction | Chad Nelson Richardson | — | (805) 336 2700 | GC, remodel, ADU | Upper Lake · Lake County | — | — |
| C&g Yard And Tree LLC DBA C&g Tree Pros | Joshua David Gray | — | (707) 295 9321 | Tree | Clearlake · Lake County | — | — |
| C&s Civil LLC | Travis Allen Coleman | — | (707) 489 9599 | Other | Lakeport · Lake County | — | — |
| Cal Core INC | James Charles Iii Darcy | — | (650) 201 0573 | Other | Kelseyville · Lake County | — | — |
| Cal Tech Pump Well & Compressor INC | Scott Matthew Brown | — | (707) 987 4488 | Other | Middletown · Lake County | — | — |
| Cal-west Painting And Finishing | Cal-west Painting And Finishing | — | (707) 364 9612 | Windows, patio, painters | Kelseyville · Lake County | — | — |
| Cali Realty & Development | Cali Realty & Development | — | (805) 775 6020 | Electricians | Clearlake · Lake County | — | — |
| Caliber Carpets And Flooring | Caliber Carpets And Flooring | — | (707) 481 2277 | Other | Lakeport · Lake County | — | — |
| Cani Contracting | John Frederick Jr Grothe | — | (707) 367 4855 | GC, remodel, ADU | Lakeport · Lake County | — | — |
| Cani Painting | Cani Painting | — | (707) 367 6188 | Windows, patio, painters | Lakeport · Lake County | — | — |
| Carpenter's Standard Construction INC | Lars On-Alexander Tisell | — | (707) 533 9543 | GC, remodel, ADU | Lakeport · Lake County | — | — |
| Carreker Plumbing | Carreker Plumbing | — | (707) 355 0044 | Other | Middletown · Lake County | — | — |
| Carter Construction | Thomas Lee Carter | — | (707) 272 3804 | GC, remodel, ADU | Upper Lake · Lake County | — | — |
| Case Excavating INC | Brian Wayne Case | caseexcavating@yahoo.com | (707) 994 6815 | Other | Clearlake · Lake County | — | — |
| Cb Plumbing | Cb Plumbing | — | (707) 350 5179 | Other | Kelseyville · Lake County | — | — |
| Charles Barron | Charles Barron | — | (707) 815 7537 | GC, remodel, ADU | Middletown · Lake County | — | — |
| Chatham Plumbing LLC | Dominic Kenneth Chatham | chathamplumbing@gmail.com | (702) 810 4332 | Other | Middletown · Lake County | — | — |
| Chavez Plumbing | Chavez Plumbing | — | (415) 859 6042 | GC, remodel, ADU | Clearlake · Lake County | — | — |