| Industrial And Commercial Electric INC | Gregory John Hannan | — | (707) 837 5591 | Electricians | Santa Rosa · Sonoma County | — | — |
| Infineon Drywall LLC | Felix Antonio Menjivar | infineondrywall@gmail.com | (707) 490 2968 | Other | Santa Rosa · Sonoma County | — | — |
| Infinite Construction & Remodeling | Eliezer Jr Navarro | — | (707) 582 0704 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Infusion INC | June Marie King | — | (707) 996 6999 | Windows, patio, painters | Sonoma · Sonoma County | — | — |
| Ingerson Builders And General Contractor | Ingerson Builders And General Contractor | — | (707) 718 6198 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Inscapes | Alain Michel Joske | gf@inscapes.com | (415) 246 6912 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Inspired Landscapes LLC | Matthew Howland Ripley | interested@domainmarket.com | (707) 395 7474 | Windows, patio, painters | Healdsburg · Sonoma County | — | — |
| Insulation Solutions | Grinberg Gabriel | — | (800) 213 0530 | Other | Santa Rosa · Sonoma County | — | — |
| Integral | James M Keven | — | (707) 328 4431 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Integrated Elements | Integrated Elements | — | (707) 477 8406 | Electricians | Occidental · Sonoma County | — | — |
| Integrated Security Controls INC | John David Pegram | — | (707) 479 9954 | Electricians | Santa Rosa · Sonoma County | — | — |
| Integrated Solutions | Paula Stephanie Ortiz | — | (833) 739 6814 | Other | Petaluma · Sonoma County | — | — |
| Integrity Build Group INC | Timothy James Kelley | info@integritybuildgroup.com | (707) 955 9308 | GC, remodel, ADU | Healdsburg · Sonoma County | — | — |
| Integrity Construction Maintenance INC | Bennett Aurthur White | — | (707) 829 5300 | GC, remodel, ADU | Sebastopol · Sonoma County | — | — |
| Integrity Glass | Integrity Glass | — | (707) 721 2612 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Integrity Paints | Integrity Paints | — | (541) 816 6897 | Windows, patio, painters | Geyserville · Sonoma County | — | — |
| Integrity Plumbing Service & Repair | Sean Micheal Kelley | — | (707) 241 3192 | Other | Windsor · Sonoma County | — | — |
| Intentional Contracting INC | Matthew Scott Davis | — | (707) 838 8904 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Intercontinental Civil Engineering Estimators | Johann Baptist Garovi | — | (415) 577 0205 | Other | Santa Rosa · Sonoma County | — | — |
| Interior Finishing INC | Darryl William Brandstrom | — | (707) 588 8502 | Windows, patio, painters | Rohnert Park · Sonoma County | — | — |
| Interiors Incorporated | Stephen Don Worthen | — | (707) 544 4770 | Other | Santa Rosa · Sonoma County | — | — |
| Interlocking Paver Nation | Renato Martins Do Carmo | — | (510) 612 0776 | Other | Rohnert Park · Sonoma County | — | — |
| International Consulting INC | Eugene Barshtak | — | (818) 402 7951 | Other | Santa Rosa Valley · Sonoma County | — | — |
| International Tile & Stone | International Tile & Stone | — | (707) 623 8394 | Other | Santa Rosa · Sonoma County | — | — |
| Interphases | Jaime Michael Wanderscheid | — | (707) 753 1750 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Intersafe Traffic Services INC | James Eric Gulbransen | — | (866) 258 8841 | Other | Santa Rosa · Sonoma County | — | — |
| Interstate Steel Builders INC | Brian Dennis Compton | — | (707) 755 1880 | GC, remodel, ADU | Windsor · Sonoma County | — | — |
| Interstellar Painting | Interstellar Painting | — | (707) 495 3767 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Intuitive Build And Design | Intuitive Build And Design | — | (707) 228 0501 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Invision Sash & Glass INC | Shelby Walburn Sieg | — | (707) 544 3068 | Windows, patio, painters | Santa Rosa · Sonoma County | — | — |
| Irg Gardener | Irg Gardener | irggardener@hotmail.com | (707) 703 0597 | Windows, patio, painters | Cotati · Sonoma County | — | — |
| Irish Setter | Irish Setter | — | (707) 766 9663 | Other | Petaluma · Sonoma County | — | — |
| Iron Dog Fabrication INC | Duncan Hayden Woods | — | (707) 579 7831 | Other | Santa Rosa · Sonoma County | — | — |
| Iron Oak Construction | Jonas William Bourland | — | (707) 326 1408 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Ironbark Arborists & Forestry | William Bashar Subaie | — | (707) 756 0490 | Tree | Sonoma · Sonoma County | — | — |
| Ironcat INC | Dustin Reagan| Congrove Dusty Congrove | — | (707) 303 0152 | Other | Santa Rosa · Sonoma County | — | — |
| Ironsight Homes Construction Corporation | Ryan Matthew Devencenzi | — | (707) 385 1490 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Ironwood Alliance INC | James Garfield Iii Laier | — | (707) 544 8070 | GC, remodel, ADU | Santa Rosa · Sonoma County | — | — |
| Ironwood Construction INC | Cody Mahan Chisham | — | (707) 338 7731 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |
| Irving Diaz Construction | Irving Diaz Calderon | — | (415) 233 1896 | GC, remodel, ADU | Petaluma · Sonoma County | — | — |