| J Tinoco Construction | Tinoco Calvillo Juan | — | (707) 480 8095 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| J W Hanson Heating And Air | James William Hanson | — | (707) 538 3329 | Other roofers | Santa Rosa · Sonoma County | — | — |
| J W Keller | J W Keller | — | (707) 494 7242 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| J Warner Enterprises | Jonathan Tyler Warner | — | (707) 206 5578 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| J Wray Construction LLC | Jeremy Michael Wray | info@jwrayconstruction.com | (707) 340 3901 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| J Z Construction | Justin Carl Zentner | — | (707) 695 7277 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| J&a Garage Door Repair INC | Orel Avraham | — | (707) 395 7137 | Other | Rohnert Park · Sonoma County | — | — |
| J&j Electric INC | Hernandez Javier | — | (707) 480 4736 | Electricians | Santa Rosa · Sonoma County | — | — |
| J&j Plask Excavating LLC | Justin Lee Plaskett | — | (707) 479 2642 | Other | Sonoma · Sonoma County | — | — |
| Jac And Brida LLC | Agustin Flores | — | (415) 272 1785 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Jace Wheeler Electrical INC | Jace Robert Wheeler | — | (530) 513 0040 | Electricians | Cloverdale · Sonoma County | — | — |
| Jack Sissel Pump Service LLC | Jack Lee Sissel | — | (707) 823 6535 | Other | Graton · Sonoma County | — | — |
| Jack Smith Glass And Sash INC | Joy Marie Smith | — | (707) 544 0640 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Jackson Ridge Flats INC | Jonathan Orvel Barker | — | (707) 724 1819 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Jackson's Rubber Stone | Jack Eric Wahl | — | (707) 843 7248 | Other | Santa Rosa · Sonoma County | — | — |
| Jacob Lopez Electric | Jacob Luis Lopez | — | (707) 974 3964 | Electricians | Windsor · Sonoma County | — | — |
| Jacobson Fence Company INC | Samual Allen Mason | — | (707) 544 8475 | Other | Santa Rosa · Sonoma County | — | — |
| Jaguar Plumbing | Jaguar Plumbing | — | (707) 477 3610 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Jalos Landscape | Jalos Landscape | — | (707) 849 0819 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| Jam Precision Flooring | Jam Precision Flooring | — | (510) 329 8522 | Other | Graton · Sonoma County | — | — |
| Jam3builders | Tony Lynn Fettkether | jam3builders@gmail.com | (707) 774 2864 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| James A Martin | James A Martin | — | (707) 334 0916 | GC, remodel, ADU | Rohnert Park · Sonoma County | — | — |
| James Dufloth Construction | James Wayne Dufloth | — | (707) 975 4435 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| James Electric | James Carr Johnson | inquiries@jameselectric.ca | (707) 579 4386 | Electricians | Santa Rosa · Sonoma County | — | — |
| James Fisher & Son INC DBA Culligan Water Of Sonoma County | Barratt Harper Fisher | — | (707) 545 1330 | Other | Santa Rosa · Sonoma County | — | — |
| James Furuli Investment Co INC | James Cory Furuli | — | (707) 762 9224 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| James Iodence | James Iodence | — | (707) 321 8770 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| James M Hendrickson | James M Hendrickson | — | (650) 520 0104 | GC, remodel, ADU | Guerneville · Sonoma County | — | — |
| James M Mc Elroy Iii Construction Co | James Madison Iii Mc Elroy | — | (707) 480 2171 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| James Meikle Landscape | James Meikle Landscape | — | (707) 763 1058 | Windows, patio, painters | Petaluma · Sonoma County | — | — |
| James Pennington Builder | James Pennington Builder | — | (707) 696 1129 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| James Reese Construction | James Albert Reese | — | (707) 971 0204 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| James Taylor | James Taylor | help@jamestaylor.com | (707) 326 2030 | Other | Cloverdale · Sonoma County | — | — |
| Jane Castle Concrete Pumping | Jane Ann Castle | — | (707) 528 7867 | Other | Santa Rosa · Sonoma County | — | — |
| Janver Holly | Janver Holly | — | (707) 387 9550 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Jarco Land INC | Garcia Garcia Ricardo | — | (707) 791 7956 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Jared Burroughs | Jared Burroughs | — | (707) 529 1811 | Windows, patio, painters | Windsor · Sonoma County | — | — |
| Jason Goett | Jason Goett | — | (707) 494 6394 | GC, remodel, ADU | Cloverdale · Sonoma County | — | — |
| Jason Hood | Jason Hood | — | (707) 583 5917 | Other | Rohnert Park · Sonoma County | — | — |
| Jason Mcclure Contracting INC | Jason William Mc Clure | — | (707) 978 9221 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |