| Lee Olaeta Plumbing | Lee Olaeta Plumbing | — | (707) 762 0105 | Other | Petaluma · Sonoma County | — | — |
| Lee Tavis Construction | Lee Michael Tavis | — | (707) 318 8874 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Lee's Painting Company | Lee Duc Nguyen | — | (707) 479 9553 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Leete Generators | Carole Anne Bliese | — | (707) 545 0484 | Electricians | Santa Rosa · Sonoma County | — | — |
| Leff Design Build | David Johnathan Leff | info@leffdesignbuild.com | (707) 823 4899 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Left Coast Painting & Drywall | Left Coast Painting & Drywall | contact@leftcoastpaint.com | (707) 478 9150 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Legacy Heating & Air | Legacy Heating & Air | — | (415) 847 6373 | HVAC | Rohnert Park · Sonoma County | — | — |
| Legacy Roofing By Ken Garman | Kenneth Allan Garman | — | (707) 566 8305 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Legacy Tree Service LLC | Elmer Fernandez | — | (707) 239 2612 | Tree | Santa Rosa · Sonoma County | — | — |
| Legend Tile And Stone | Fred George Flynn | — | (707) 955 7005 | Other | Forestville · Sonoma County | — | — |
| Leland E Parks | Leland E Parks | — | (707) 540 4299 | Electricians | Santa Rosa · Sonoma County | — | — |
| Leland Plumbing Heating & Air Cond | Jeffrey Michael Leland | — | (707) 838 9600 | HVAC | Windsor · Sonoma County | — | — |
| Lemur Tree Aid LLC | Genoc Franco | — | (707) 888 1429 | Tree | Sebastopol · Sonoma County | — | — |
| Lennon Heating & Air Conditioning INC | Ronald Joseph Lennon | — | (707) 935 3625 | HVAC | Sonoma · Sonoma County | — | — |
| Lenny Construction | James Patrick Lenny | — | (707) 237 1816 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Lenny Depucci Painting | Lenny Depucci Painting | — | (415) 806 1296 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Leo's Construction And Painting | Leonardo Martinez Macedonio | — | (707) 280 8629 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Leo's Roofing INC DBA Leo's Gutters | Leopoldo Avalos | — | (707) 527 1289 | Other roofers | Santa Rosa · Sonoma County | — | — |
| Leon Painting | Leon Painting | info@leonpainting.com | (707) 623 8509 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Leon Quality Construction | Selvin Osvaldo Leon Morales | — | (707) 486 8439 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Leonardo's Casework & Design INC | William Frank Leonardo | — | (707) 525 1233 | Other | Santa Rosa · Sonoma County | — | — |
| Leoni's Quality Painting INC | Anthony Leighton Ramsey Leoni | — | (707) 393 7602 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Les Petersen Drilling & Pump INC | Linda Lee Pool | — | (707) 545 0246 | Other | Santa Rosa · Sonoma County | — | — |
| Lesieur INC | Christopher Frederick| Le Sieur Chris Frederick Le Sieur | — | (415) 892 1802 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Lesik Construction | Michael Roy Lesik | — | (707) 799 0255 | GC, remodel, ADU | Occidental · Sonoma County | — | — |
| Lets Build | Lets Build | — | (707) 703 2134 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Level House Construction INC | Jose Santos Pina Rivera | — | (707) 718 5317 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Levi Gurule | Levi Gurule | — | (707) 478 6205 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Levis Concrete Construction INC | Magana Jesus Diaz | — | (707) 694 9364 | Other | Santa Rosa · Sonoma County | — | — |
| Lewis Mechanical Services INC | Gregory William Lewis | — | (707) 544 1277 | HVAC | Santa Rosa · Sonoma County | — | — |
| Leyby Aroldo Diaz Calderon | Leyby Aroldo Diaz Calderon | — | (415) 299 0433 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Lhs Construction LLC | Lance Scott Schmidt | — | (415) 312 5012 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Liam Stewart Painting | Liam Stewart Painting | — | (415) 933 1111 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Liarakos Construction | Nathan C Liarakos | — | (707) 484 8971 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Liberty Contractors INC | Renee Brinkley Capriola | — | (415) 725 3061 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Liberty Plumbing | Liberty Plumbing | — | (707) 537 1400 | Other | Santa Rosa · Sonoma County | — | — |
| Licea's Stucco | Licea's Stucco | — | (707) 591 5624 | Other | Santa Rosa · Sonoma County | — | — |
| Lily Huang General Contractor | Lily Huang General Contractor | — | (415) 308 0882 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Lima Electric | John Couto Lima | — | (707) 393 1497 | Electricians | Rohnert Park · Sonoma County | — | — |
| Lind Marine Incorporated | Aaron Jude Lind | — | (707) 762 7251 | Other | Petaluma · Sonoma County | — | — |