| Langdon Installations | Langdon Installations | — | (707) 477 5216 | Other | Petaluma · Sonoma County | — | — |
| Lange & Company Builders INC | Jacob Michael Lange | — | (707) 849 0856 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Lanning Steel Design | Lanning Steel Design | — | (707) 310 1820 | Other | Sonoma · Sonoma County | — | — |
| Lanway Construction Company INC | Danny John Langer | — | (707) 538 3055 | Other | Santa Rosa · Sonoma County | — | — |
| Lara's Drywall INC | Juan Manuel Flores Lara | — | (415) 786 8248 | Other | Santa Rosa · Sonoma County | — | — |
| Larbre Well Drilling And Pumps INC | Ross Brian Dencklau | — | (707) 996 1819 | Other | Sonoma · Sonoma County | — | — |
| Lario's Tree Service | Larios Vargas Leobardo | — | (707) 815 3583 | Tree | El Verano · Sonoma County | — | — |
| Larrabure Construction And Design | Ryan Baker Larrabure | — | (707) 241 7488 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Larry Allen Hetherington | Larry Allen Hetherington | — | (925) 521 4777 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Larry Dellard Wallcovering & Painting | Larry Dellard Wallcovering & Painting | — | (707) 494 1776 | Windows, patio, painters | Sebastopol · Sonoma County | — | — |
| Larry Drew Backhoe Service | Larry Wallace Drew | — | (707) 753 0843 | Other | Penngrove · Sonoma County | — | — |
| Larry Horne Builder | Larry Horne Builder | larry@larryhornebuilder.com | (707) 484 3988 | GC, remodel, ADU | Duncans Mills · Sonoma County | — | — |
| Larry Lancina - General Contractor | Larry Lancina - General Contractor | — | (707) 318 6620 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Larry M Ono | Larry M Ono | — | (707) 953 5022 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Larry Poirier Jr | Larry Poirier Jr | — | (707) 481 1999 | Other | Santa Rosa · Sonoma County | — | — |
| Larsen Energy Systems INC | Casey Russell Larsen | — | (707) 486 3757 | HVAC | Santa Rosa · Sonoma County | — | — |
| Las Fuentes Construction | Herly Clisman De Leon Mazariegos | — | (415) 846 6723 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lasco Electric Incorporated | Alice Lisa Allen | — | (707) 542 6231 | Electricians | Santa Rosa · Sonoma County | — | — |
| Laskey Electric | Mark Paul Laskey | contact@sansoxygen.com | (707) 239 2722 | Electricians | Cloverdale · Sonoma County | — | — |
| Lasley Mechanical LLC | Spencer Hale Lasley | — | (707) 953 3695 | HVAC | Penngrove · Sonoma County | — | — |
| Lasting Impressions In Concrete | Brian Matthew Ciocci | — | (707) 763 5359 | Other | Petaluma · Sonoma County | — | — |
| Latitude Construction | Steve Paul Caratti | — | (707) 887 7080 | GC, remodel, ADU | Forestville · Sonoma County | — | — |
| Laura D Mason | Laura D Mason | — | (707) 829 9292 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Lavish & Son's Painting INC | Luis Alfonso Villagomez Camacho | — | (707) 703 6722 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Lawrence Fraser Construction | Lawrence James Fraser | — | (415) 308 0294 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Layman Drywall | Layman Drywall | — | (707) 544 9221 | Other | Santa Rosa · Sonoma County | — | — |
| Lazaro Flooring | Lazaro Flooring | — | (707) 494 1140 | Other | Rohnert Park · Sonoma County | — | — |
| Lazco Construction | Christian Hale Lasley | — | (415) 816 2000 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| Lcr | Luke Alfred Larson | — | (415) 596 6853 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Lda Painting | Lda Painting | — | (707) 280 7303 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Le Brett Construction | Michael Joseph Le Brett | — | (707) 433 3522 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Le Duc & Dexter INC | Ralph Arthur Dexter | — | (707) 575 1500 | HVAC | Santa Rosa · Sonoma County | — | — |
| Leading Edge Painting | Leading Edge Painting | — | (707) 540 3738 | Windows, patio, painters | Cloverdale · Sonoma County | — | — |
| Lebrun Excavation And Concrete | Lebrun Excavation And Concrete | — | (707) 481 1415 | Other | Santa Rosa · Sonoma County | — | — |
| Ledesma Heating & Air | Ledesma Heating & Air | — | (707) 799 5891 | HVAC | Petaluma · Sonoma County | — | — |
| Ledesma Tile & Stone | Ledesma Tile & Stone | — | (707) 975 8201 | Other | Santa Rosa · Sonoma County | — | — |
| Ledson Construction | Steven Noble Ledson | — | (707) 537 3810 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Ledson Development LLC | Michele Lynn Ledson | — | (707) 537 3810 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Lee Kunken | Lee Kunken | — | (707) 664 8080 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Lee Moen Construction | Lee Michael Moen | — | (707) 318 5591 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |