| Joyner Electric INC | Danielle Renee Meyers | — | (805) 440 3274 | Electricians | Forestville · Sonoma County | — | — |
| Jp Mechanical HVAC | John David Pleune | — | (707) 978 8176 | HVAC | Santa Rosa · Sonoma County | — | — |
| Jpl Builders INC | Jean-paul Omar Levesque | sales@jplbuilders.com | (707) 974 1029 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Jpl Custom Builders INC DBA Shelter Construction | James Paul Leuschner | — | (415) 225 9877 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Jpr Landscapes LLC | Tapia Jose Rodriguez | — | (707) 241 5615 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Jr's Concrete | Jr's Concrete | — | (707) 433 7439 | Other | Healdsburg · Sonoma County | — | — |
| Jrcal Construction INC | Jose Antonio Moreno Rivadeneyra | — | (707) 978 6244 | Other | Santa Rosa · Sonoma County | — | — |
| Js Fire Protection | Js Fire Protection | — | (707) 291 8316 | Other | Petaluma · Sonoma County | — | — |
| Js Flooring | Js Flooring | — | (707) 758 1903 | Other | Rohnert Park · Sonoma County | — | — |
| Js Landscape INC | Jose Luis Silva Garcia | jslandscapeconstructionllc@gmail.com | (707) 207 1717 | Windows, patio, painters | Cloverdale · Sonoma County | — | — |
| Jsb Electric | Justin Scott Beth | — | (707) 483 2604 | Electricians | Windsor · Sonoma County | — | — |
| Juan Contreras Landscaping | Juan Contreras Landscaping | — | (707) 799 9113 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Juan Painting & Design | Juan Painting & Design | — | (707) 209 4652 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Juan Velasco Perez | Juan Velasco Perez | — | (707) 364 6241 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| Juan's Landscape | Juan's Landscape | juanslandscape@hotmail.com | (707) 935 3559 | Windows, patio, painters | El Verano · Sonoma County | — | — |
| Juan's Trade Build And Repair | Juan's Trade Build And Repair | — | (707) 583 4915 | GC, remodel, ADU | Forestville · Sonoma County | — | — |
| Juanito Fence And Gates Company | Garcia Munoz Juan | — | (951) 218 7095 | Other | Cloverdale · Sonoma County | — | — |
| Jubilee Building Company LLC | Andrew Nickolas Bosch | shauna@jubileebuilding.com | (707) 477 3588 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Jules Volper | Jules Volper | — | (707) 321 3066 | Other | Cloverdale · Sonoma County | — | — |
| Junnior's Construction | Osmar Vinicio Vera Lopez | osmarv1997@yahoo.com | (707) 364 9429 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Justin Brandon Paul Goebel | Justin Brandon Paul Goebel | — | (707) 393 9696 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Justin Hunter | Justin Hunter | — | (707) 541 0700 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Justin Koenig | Justin Koenig | — | (707) 888 9617 | Other | Cotati · Sonoma County | — | — |
| Justin Lewis | Justin Lewis | justin@justinlewis.com | (707) 974 1290 | HVAC | Sebastopol · Sonoma County | — | — |
| Justin Samples Concrete Pumping | Justin James Samples | — | (707) 889 1983 | Other | Santa Rosa · Sonoma County | — | — |
| Justin Sheehan | Justin Sheehan | — | (707) 774 2482 | Electricians | Camp Meeker · Sonoma County | — | — |
| Justo G De La O DBA De La O Construction | Justo Gomez De La O | — | (707) 292 6317 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| Juve Landscape Management | Juve Landscape Management | — | (707) 849 4461 | Windows, patio, painters | Windsor · Sonoma County | — | — |
| Jv Drywall | Jv Drywall | impallari@gmail.com | (707) 933 7368 | Other | Santa Rosa · Sonoma County | — | — |
| Jv Plumbing & Backflow | Jv Plumbing & Backflow | — | (707) 799 2692 | Other | Windsor · Sonoma County | — | — |
| Jw Construction | William Jacob White | — | (707) 331 0185 | GC, remodel, ADU | Sonoma · Sonoma County | — | — |
| Jw Construction LLC | Ronald Blaine Johnson | — | (707) 318 6422 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| K & E Construction | Kurt Eric Eichstaedt | — | (707) 591 3391 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| K & L Construction Company INC | Alec Craig Lok | — | (707) 795 7924 | GC, remodel, ADU | Penngrove · Sonoma County | — | — |
| K & M Renovations INC | Constance Alexis Kullberg | — | (415) 810 1210 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| K & P Kelly INC | Patrick Kenneth Kelly | — | (707) 579 4104 | Other | Windsor · Sonoma County | — | — |
| K 2 Flooring | K 2 Flooring | — | (707) 623 4131 | Other | Healdsburg · Sonoma County | — | — |
| K A Bine Construction INC | Kirk Alan Bine | — | (707) 974 8640 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| K B I Painting INC | James Damian Koreen | — | (707) 795 4955 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| K D S Construction Co | Kevin Donovan Smith | — | (707) 758 4796 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |