| I B Y Construction INC | Juan Jose Ponce | — | (951) 634 9080 | GC, remodel, ADU | Desert Hot Springs · Riverside County | — | — |
| I C A Construction | Jose Isidoro Camacho Alegria | — | (951) 443 6866 | GC, remodel, ADU | Wildomar · Riverside County | — | — |
| I E Demolition | I E Demolition | — | (213) 408 2985 | Other | Jurupa Valley · Riverside County | — | — |
| I E Plumbing Services INC | Julio Cesar Arias | — | (951) 375 9599 | Other | Sun City · Riverside County | — | — |
| I E Restoration INC | Daniel Lacatus | — | (951) 588 6737 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| I Electric | Zachary J.o. Gilbert | — | (808) 960 4376 | Electricians | Menifee · Riverside County | — | — |
| I G Landscaping | I G Landscaping | — | (951) 352 4238 | Windows, patio, painters | Riverside · Riverside County | — | — |
| I H Landscaping Maintenance INC | Aguilar Ismael Hernandez | — | (760) 835 1870 | Windows, patio, painters | Cathedral City · Riverside County | — | — |
| I J N Construction INC | Alejandrina Elizabeth Vides | — | (323) 558 3236 | GC, remodel, ADU | Jurupa Valley · Riverside County | — | — |
| I P Painting | Steve Michael Quezada | — | (951) 637 4807 | Windows, patio, painters | Lake Elsinore · Riverside County | — | — |
| I Rooter Plumbing | I Rooter Plumbing | — | (760) 902 2281 | Other | Cathedral City · Riverside County | — | — |
| I T R Construction | Manh Duc Mai | — | (714) 724 4052 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| I V Construction | Ivan Alejandro Valle Diaz | — | (626) 240 3635 | GC, remodel, ADU | Moreno Valley · Riverside County | — | — |
| I Villegas INC DBA Innovative Concrete And Design | Isai Villegas | — | (760) 704 3841 | Other | Hemet · Riverside County | — | — |
| I W I Contracting | David Brian Queyrel | — | (888) 494 4283 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| I W S C INC DBA Indian Wells Stamp Crete | Pedro Venegas | — | (760) 567 6370 | GC, remodel, ADU | Beaumont · Riverside County | — | — |
| I Wire Electric | Todd Michael Hector | — | (714) 616 1351 | Electricians | Corona · Riverside County | — | — |
| I&g Screens INC DBA As Doors Gates And Activating Devices | Gabriel Ismael Garcia | — | (951) 836 4158 | Other | Riverside · Riverside County | — | — |
| I-sol Electrical Services | Eusebio Torres | — | (866) 980 9195 | Electricians | Moreno Valley · Riverside County | — | — |
| Ia Team INC DBA Integrity Air Heating And Cooling Specialist | Christopher Clayton Johnson | — | (951) 306 9061 | HVAC | Murrieta · Riverside County | — | — |
| Iacono Development INC | August Anthony Iacono | — | (951) 634 6381 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| Ial Construction INC | Daniel Anthony Ortega | — | (951) 662 6723 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Ian Kiernicki | Ian Kiernicki | — | (760) 774 9015 | Windows, patio, painters | Cathedral City · Riverside County | — | — |
| Ian Patrick Daley | Ian Patrick Daley | — | (951) 691 0525 | Other | Murrieta · Riverside County | — | — |
| Ianniciello Construction Co | Jeffrey Michael Ianniciello | — | (909) 855 6989 | GC, remodel, ADU | Norco · Riverside County | — | — |
| Iaq Security Tech INC | Fermin Daniel Rivera | — | (213) 984 6062 | HVAC | Perris · Riverside County | — | — |
| Iaw Construction INC | Lourdes Wicklow | iwicklow@iawconstruction.com | (951) 681 6900 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Ib Plumbing LLC | Jonathan Guadalupe Avila Briseno | — | (714) 833 6823 | Other | Jurupa Valley · Riverside County | — | — |
| Ibarra's Air Conditioning And Heating | Ibarra's Air Conditioning And Heating | — | (760) 880 7083 | HVAC | Indio · Riverside County | — | — |
| Ibarra's General Engineering | Arturo Lopez Ibarra | — | (909) 342 8447 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Ibarra's Pools INC | Liliana Escudero | — | (909) 643 9347 | Pool | San Jacinto · Riverside County | — | — |
| Ibex Building & Development INC | Raul Vela Cabrera | — | (909) 910 2199 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Ibk Construction INC | Miguel Angel Ramirez Chavarria | — | (951) 315 9064 | GC, remodel, ADU | Moreno Valley · Riverside County | — | — |
| Ibrahem Alkhatatbeh | Ibrahem Alkhatatbeh | — | (714) 220 7067 | HVAC | Riverside · Riverside County | — | — |
| Ibrahim Mahmic | Ibrahim Mahmic | — | (760) 831 8831 | GC, remodel, ADU | Thousand Palms · Riverside County | — | — |
| Ic Air Conditioning | Ic Air Conditioning | — | (951) 840 0111 | HVAC | Riverside · Riverside County | — | — |
| Ic Mobile Home Services | Isaac Cruz | — | (951) 575 5244 | Other | Perris · Riverside County | — | — |
| Ic&d Corp | Jesse Lee Crocker | — | (760) 524 2616 | Other | Wildomar · Riverside County | — | — |
| Icebox HVAC Solutions | Spenser Bennie Gomez | — | (951) 403 7462 | HVAC | Riverside · Riverside County | — | — |
| Icee Hot Air Conditioning & Heating | Bernie Preston Del Rojo | — | (951) 427 9117 | HVAC | Corona · Riverside County | — | — |