| Kunkle Electric INC | Justin James Kunkle | info@kunkleelectric.com | (707) 975 2363 | Electricians | Santa Rosa · Sonoma County | — | — |
| Kvar Electrical | Jeffrey John Boheim | — | (707) 888 3898 | Electricians | Sebastopol · Sonoma County | — | — |
| Kw Electric LLC | Kurt Mark Woltering | — | (415) 720 0208 | Electricians | Penngrove · Sonoma County | — | — |
| Kyle Woicicki Construction | Kyle Kristopher Woicicki | — | (707) 595 8618 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| L A D Excavation INC | Lucas Arlo Allen-Duenas | — | (707) 888 2556 | Other | Santa Rosa · Sonoma County | — | — |
| L A Diaz Concrete | L A Diaz Concrete | — | (925) 586 0820 | Other | Santa Rosa · Sonoma County | — | — |
| L B Kegler General Contractor | L B Kegler General Contractor | — | (415) 706 9907 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| L B L Construction INC | Baranauskas Linas | — | (707) 292 8854 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| L Briseno Construction | Luis Uriel Briseno Basulto | — | (707) 694 7315 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| L F G | Eugene John Lenzi | — | (707) 529 4991 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| L F Garage Doors | L F Garage Doors | lfranco1225@hotmail.com | (707) 326 2230 | Other | Santa Rosa · Sonoma County | — | — |
| L J Landscape Management & Creation | Jose Guadalupe Jauregui | — | (707) 773 3973 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| L-n-r Security | L-n-r Security | delta1@lnrsecurity.com | (707) 778 3700 | Alarm and generators | Petaluma · Sonoma County | — | — |
| La Costa Landscaping | Jesus Carlos Lopez Cortes | — | (707) 235 5982 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| La Noire & Co Construction | Luis Alberto La Noire | — | (415) 720 5607 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| La Zucena Concrete & Landscaping | La Zucena Concrete & Landscaping | — | (707) 338 2199 | Windows, patio, painters | Penngrove · Sonoma County | — | — |
| Labonte Painting Of Marin/sonoma | Labonte Painting Of Marin/sonoma | — | (707) 591 9121 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Labourdette Construction | Stephen Albert Labourdette | — | (707) 824 0544 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Labrador Electric LLC | Eric Paul Poppe | — | (415) 497 5501 | Electricians | Sebastopol · Sonoma County | — | — |
| Ladder Brothers Construction | Timothy Michael Berman | theladderbrothers@gmail.com | (707) 483 9164 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Lady B Electric INC | Brittan Leigh Scott | ladybelectric@gmail.com | (707) 508 5398 | Electricians | Santa Rosa · Sonoma County | — | — |
| Laguna Landscaping | Brent Charles Reed | — | (707) 527 9277 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Lagunas | Miguel Mendoza Lagunas | — | (707) 596 1466 | Windows, patio, painters | Graton · Sonoma County | — | — |
| Laid Out Tile & Stone | Laid Out Tile & Stone | — | (707) 975 4091 | Other | Santa Rosa · Sonoma County | — | — |
| Lalo's Garage Door's | Lalo's Garage Door's | info@lalosgaragedoors.com | (707) 396 8773 | Other | Santa Rosa · Sonoma County | — | — |
| Lamberson Tile | Lamberson Tile | — | (707) 483 0784 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lambert Construction | Jacob David Lambert | proteam@mopro.com | (707) 535 9385 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lance M Parks Construction | Lance Martin Parks | — | (707) 843 1055 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Lancer Miller | Lancer Miller | — | (707) 888 9456 | Electricians | Cloverdale · Sonoma County | — | — |
| Lancewood Construction | John Jeffrey Gusman | — | (707) 538 3621 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Land Revision | Shane Michael Hudlin | — | (707) 790 5263 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Landco Environments | David Alan Smith | — | (707) 347 5992 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Landers Curry INC | Jon Landers Curry | jon@landerscurry.com | (707) 931 4422 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Landesign Construction And Maintenance INC | John Howard Fitzgerald | — | (707) 578 2657 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Landis Construction | Joshua Michael Landis | — | (707) 815 3406 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Landmark Concrete Construction INC | Adam Robert Landers | — | (707) 836 1212 | Other | Windsor · Sonoma County | — | — |
| Landmark Contracting INC | Seth Raeble Maze | — | (707) 757 5050 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Lands Electric | David Jeremiah Lands | — | (707) 332 2606 | Electricians | Cloverdale · Sonoma County | — | — |
| Landscape Restoration By Dan Pozzi | Landscape Restoration By Dan Pozzi | — | (707) 206 8404 | Windows, patio, painters | Sebastopol · Sonoma County | — | — |
| Lane's Plumbing | Lane's Plumbing | — | (707) 833 2930 | Other | Kenwood · Sonoma County | — | — |