| Integrity Contractor Group | Jessie James Canchola | — | (805) 656 2214 | GC, remodel, ADU | Santa Paula · Ventura County | — | — |
| Integrity Design Builders INC | Francisco Joseph Hernandez | — | (805) 402 3452 | GC, remodel, ADU | Oxnard · Ventura County | — | — |
| Integrity H V A C Co | Rafael Viera Dumas | — | (818) 900 3390 | HVAC | Simi Valley · Ventura County | — | — |
| Integrity Heating And Air INC | Luis Alfonso Oceguera | — | (805) 273 1973 | HVAC | Camarillo · Ventura County | — | — |
| Integrity Painting | Integrity Painting | — | (805) 746 8569 | Windows, patio, painters | Ojai · Ventura County | — | — |
| Integrity Plumbing Inspection | Integrity Plumbing Inspection | — | (805) 603 6303 | Other | Camarillo · Ventura County | — | — |
| Integrity Tree Brush And Hauling | Integrity Tree Brush And Hauling | — | (805) 501 2413 | Tree | Simi Valley · Ventura County | — | — |
| Integrity Workplan INC DBA Boaz Construction | Carla Vanessa Jones | — | (310) 493 1625 | GC, remodel, ADU | Newbury Park · Ventura County | — | — |
| Interlocking Paving Systems INC | Per Orla Christiansen | — | (805) 652 0300 | GC, remodel, ADU | Ventura · Ventura County | — | — |
| International Terrazzo | Ever Daniel Linares | internationalterrazzo@gmail.com | (619) 804 7344 | Other | Moorpark · Ventura County | — | — |
| Interstate Rebar INC | Ronald Willis Moore | — | (805) 643 6892 | Other | Oak View · Ventura County | — | — |
| Interstate Striping & Signs INC | Derik Allen Boelman | — | (805) 208 5925 | Other | Ventura · Ventura County | — | — |
| Inverter Technology INC | James D Stevens | accounting@invertertechnology.com | (805) 477 0612 | Electricians | Ventura · Ventura County | — | — |
| Ira Cornell Electric INC | Ira Matthew Cornell | — | (805) 797 0788 | Electricians | Ventura · Ventura County | — | — |
| Ireland's Pool Service INC | Steven Ray Ireland | christina@irelandspoolservice.com | (818) 635 4843 | Pool | Newbury Park · Ventura County | — | — |
| Ironmark Earthworks INC | Christopher Patrick Wolf | — | (805) 233 2470 | Other | Moorpark · Ventura County | — | — |
| Ironworks By Tony Castro | Marco Antonio Castro | contact@ironworksbytonycastro.com | (805) 248 5477 | Other | Santa Paula · Ventura County | — | — |
| Island Home Inspections | Island Home Inspections | — | (805) 390-8718 | Inspectors | Ventura · Ventura County | — | — |
| Island Tile Cleaning | Island Tile Cleaning | — | (805) 451 6394 | Other | Ventura · Ventura County | — | — |
| Ismael Castorena | Ismael Castorena | — | (818) 516 5715 | Other | Fillmore · Ventura County | — | — |
| Israel J Bronstein | Israel J Bronstein | — | (805) 525 0027 | Other | Thousand Oaks · Ventura County | — | — |
| Israel Parker | Israel Parker | — | (513) 633 8783 | Electricians | Ojai · Ventura County | — | — |
| Itech Smart Home INC | Thomas Chad Robinson | — | (805) 673 8414 | Other | Ventura · Ventura County | — | — |
| Iv's Electric | Ivan Amaury Ii Velez | — | (805) 217 9096 | Electricians | Ventura · Ventura County | — | — |
| Ivan Lauritzen | Ivan Lauritzen | — | (818) 419 2100 | GC, remodel, ADU | Simi Valley · Ventura County | — | — |
| Ivers Construction | Donald Elliot Ivers | jeff@iversconstruction.com | (805) 680 1067 | GC, remodel, ADU | Ojai · Ventura County | — | — |
| Iverson Construction INC | Brian David Iverson | youtoubefix@gmail.com | (805) 377 8402 | GC, remodel, ADU | Simi Valley · Ventura County | — | — |
| Ivory Coast Landscape Co | Montes Alejandro | — | (805) 494 4959 | Windows, patio, painters | Thousand Oaks · Ventura County | — | — |
| J & F Builders INC | Jose Estrada Ramirez | — | (805) 526 3684 | GC, remodel, ADU | Simi Valley · Ventura County | — | — |
| J & H Engineering General Contractors INC | Sandra Sue Janotta | — | (805) 987 8414 | GC, remodel, ADU | Camarillo · Ventura County | — | — |
| J & K Mott Construction INC | John Neville Mott | — | (805) 404 5455 | GC, remodel, ADU | Simi Valley · Ventura County | — | — |
| J & R Electric | Jerry Lee Humphries | — | (805) 217 5567 | Electricians | Simi Valley · Ventura County | — | — |
| J & R Trucking INC | Rock Warren Jr Ake | — | (805) 529 7437 | Other | Moorpark · Ventura County | — | — |
| J & S Plumbing Pros INC | Sean Robert Edwardsen | — | (818) 585 4099 | Other | Simi Valley · Ventura County | — | — |
| J - Mack Plumbing INC | Aguilera Javier | — | (805) 777 9252 | GC, remodel, ADU | Thousand Oaks · Ventura County | — | — |
| J - Tech Construction | Julio Adrian Ramos | — | (805) 509 8297 | Electricians | Oxnard · Ventura County | — | — |
| J A Flooring | J A Flooring | — | (805) 443 0798 | Other | Oxnard · Ventura County | — | — |
| J A L Construction | Moshe Mark Levi | — | (818) 482 0599 | Electricians | Thousand Oaks · Ventura County | — | — |
| J Acosta Framing And Construction | Acosta Jaime | — | (805) 607 2912 | GC, remodel, ADU | Santa Paula · Ventura County | — | — |
| J And A Welding Services INC | Ashley Garcia | — | (805) 874 1180 | Other | Oxnard · Ventura County | — | — |