| Linden's Pool Service | Jered Benjamin Linden | — | (707) 217 3533 | Pool | Sonoma · Sonoma County | — | — |
| Lion's & Son Painting INC | Claudio Roberto De Leon Ortiz | — | (415) 583 6881 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Lit Electric LLC | Branden Matthew Ellis | — | (707) 620 4548 | Electricians | Windsor · Sonoma County | — | — |
| Live Better | Philip Burke Lynch | — | (707) 400 7672 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Live Oak Tree Service | Frank Ramon Rihtarshich | — | (707) 364 3097 | Tree | Petaluma · Sonoma County | — | — |
| Lj Landscaping | Lj Landscaping | hello@reallygreatsite.com | (707) 364 6923 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Lm Jones Electric INC | Laura Lolly Marianne Jones | — | (707) 799 6374 | Electricians | Sonoma · Sonoma County | — | — |
| Local Metal Ornamental | Local Metal Ornamental | — | (512) 825 5030 | Other | Cotati · Sonoma County | — | — |
| Locati Plumbing | Locati Plumbing | — | (707) 230 1818 | Other | Sonoma · Sonoma County | — | — |
| Lock And Gate Security | Lock And Gate Security | — | (707) 824 1366 | Alarm and generators | Sebastopol · Sonoma County | — | — |
| Lock Stop And Key | Lock Stop And Key | — | (707) 621 5397 | Other | Santa Rosa · Sonoma County | — | — |
| Lockwood Builders | Lockwood Builders | — | (707) 975 8378 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lodolce Electric LLC | Joseph Kendall Lodolce | office@lodolceelectric.com | (707) 494 1611 | Electricians | Windsor · Sonoma County | — | — |
| Log Prince Construction INC | Salvador G Ochoa | — | (707) 494 3988 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Logan - Enos Construction INC | Eric Logan Enos | — | (707) 230 7042 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Logan Mello Construction Co | Logan Parma Mello | — | (707) 535 9807 | GC, remodel, ADU | Guerneville · Sonoma County | — | — |
| Logsdon Construction | Nathan Zane Logsdon | — | (707) 535 6466 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lomax Termite Control | Lomax Termite Control | — | (707) 996-7732 | Pest, tile roofs | Sonoma · Sonoma County | — | — |
| Lone Pine Electric LLC | James Patrick Soza | — | (707) 213 8550 | Electricians | Sebastopol · Sonoma County | — | — |
| Longevity Construction Company | Michael Kim Long | mike@longevityconstruction.com | (707) 795 8112 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Longhorn Construction | Reyes Kimberly | — | (707) 721 6692 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Longview Tree Care | Cameron Scott Long | — | (707) 483 2208 | Other | Santa Rosa · Sonoma County | — | — |
| Lonnie Hoyt | Lonnie Hoyt | — | (707) 953 7563 | GC, remodel, ADU | Cazadero · Sonoma County | — | — |
| Lopez Unlimited Painting & Staining INC | Rodriguez Ernesto Lopez | — | (707) 889 0905 | Windows, patio, painters | Cloverdale · Sonoma County | — | — |
| Lorenzini Fire Protection | Lorenzini Fire Protection | — | (707) 477 9383 | Other | Sonoma · Sonoma County | — | — |
| Lorenzo Moreno Martinez | Lorenzo Moreno Martinez | — | (707) 596 0710 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Lorenzo Patino Mendez | Lorenzo Patino Mendez | — | (707) 303 6247 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lotus Construction & Design INC DBA Ironvine Construction | Bret Karl Munson | — | (707) 672 5708 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Lotus Construction INC | Steven Edward Sutcliffe | — | (707) 479 5017 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lotus Electric | Cole Seabrook Kapple | — | (707) 235 6583 | Electricians | Santa Rosa · Sonoma County | — | — |
| Loud And Clear INC | Neville Roomy Hormuz | — | (707) 665 5650 | Other | Cotati · Sonoma County | — | — |
| Louis A Vierra | Louis A Vierra | — | (707) 888 6963 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Louis Debret DBA Lpd Construction | Louis Paul Debret | — | (530) 919 2862 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Love - Light Electric | Ryan Reed Densmore | — | (707) 396 4828 | Electricians | Cotati · Sonoma County | — | — |
| Low Voltage Security | Paul Daniel Thompson | info@lowvoltagesecurity.com | (707) 620 0889 | Electricians | Windsor · Sonoma County | — | — |
| Lowell Chaput Metalsmith | Lowell Chaput Metalsmith | — | (707) 586 1324 | Other | Rohnert Park · Sonoma County | — | — |
| Lr Bros Painting INC | Lizardo Rodriguez | lizardospainting85@gmail.com | (707) 529 7436 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Lr Concrete Construction | Luis Daniel Rueda | — | (510) 921 0498 | Other | Windsor · Sonoma County | — | — |
| Lrm Concrete Co | Leonardo Mitchell Ramirez Mata | office@lrm-concrete.com | (707) 495 4329 | Other | Santa Rosa · Sonoma County | — | — |
| Ls Paving | Ls Paving | — | (707) 338 5044 | Other | Rohnert Park · Sonoma County | — | — |