| J M E Construction Services INC | Michael Hamacher | — | (415) 722 8060 | GC, remodel, ADU | Indian Wells · Riverside County | — | — |
| J M Interiors | J M Interiors | — | (951) 217 8016 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| J M J Construction | Jordan Christopher Moisa | — | (562) 318 4733 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| J M K Electric | Joshua Michael Kalepp | — | (760) 218 1172 | Electricians | Bermuda Dunes · Riverside County | — | — |
| J M Landscape Design | J M Landscape Design | — | (760) 601 0590 | Windows, patio, painters | Thermal · Riverside County | — | — |
| J M Plastering INC | Jonas Juan Mena Marron | — | (951) 250 4842 | Other | Riverside · Riverside County | — | — |
| J M R Electric Co | Jose Manuel Ramirez | — | (760) 698 9367 | Electricians | Indio · Riverside County | — | — |
| J M Stitt Construction INC | Julia Teofilija Stitt | — | (951) 271 3440 | GC, remodel, ADU | Corona · Riverside County | — | — |
| J Mark Enterprises INC | John Mark Plocher | — | (951) 977 9660 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| J Mechling Construction | John Bryan Mechling | j.mechling.construction@gmail.com | (714) 453 7491 | GC, remodel, ADU | Corona · Riverside County | — | — |
| J Meda Pumping | J Meda Pumping | — | (562) 217 9232 | Other | Canyon Lake · Riverside County | — | — |
| J N B Interiors INC | Joseph Nathaniel Bender | — | (909) 261 9295 | GC, remodel, ADU | Corona · Riverside County | — | — |
| J N C Electrical Contractor | Jesus Lopez | — | (562) 833 0549 | Electricians | Corona · Riverside County | — | — |
| J N K Painting | Chi Won Kim | — | (714) 719 7857 | Windows, patio, painters | Corona · Riverside County | — | — |
| J O B Electric | Jevon Oaks Browning | — | (951) 492 8798 | Electricians | Idyllwild · Riverside County | — | — |
| J One Plumbing Service Corp | Juan Jose Hernandez Barrera | — | (714) 519 9248 | Other | Beaumont · Riverside County | — | — |
| J P Construction | Ponce Jaime | — | (626) 494 1732 | GC, remodel, ADU | Beaumont · Riverside County | — | — |
| J P Contracting | John Paul Ivicevic | — | (951) 677 7363 | Electricians | Murrieta · Riverside County | — | — |
| J P Custom Contractors INC | Jara Eduardo | office@jpcustomcontractors.com | (760) 673 6843 | GC, remodel, ADU | Cathedral City · Riverside County | — | — |
| J P Custom Pools | J P Custom Pools | — | (626) 991 3823 | Pool | Eastvale · Riverside County | — | — |
| J P I Development Group INC | Bradley Scott Janikowski | — | (951) 973 7680 | GC, remodel, ADU | Murrieta · Riverside County | — | — |
| J P L Landscape Contractor | J P L Landscape Contractor | — | (951) 452 7385 | Windows, patio, painters | Riverside · Riverside County | — | — |
| J P Nelson & Sons Construction INC | Jon Paul Nelson | — | (951) 836 0633 | GC, remodel, ADU | Banning · Riverside County | — | — |
| J P Plumbing Systems INC | Richard Jason Pittman | — | (951) 789 5579 | Other | Riverside · Riverside County | — | — |
| J P R Construction | Juan Pasos Rubio | — | (760) 835 7916 | GC, remodel, ADU | Indio · Riverside County | — | — |
| J Performance Construction | Cristian Jovani Contreras | — | (909) 241 7196 | GC, remodel, ADU | Jurupa Valley · Riverside County | — | — |
| J R A Painting INC | Helmut Wolfgang M Stein | — | (951) 751-4651 | Windows, patio, painters | Riverside · Riverside County | — | — |
| J R Brannen Painting | J R Brannen Painting | john@jrbrannenpainting.com | (951) 966 6628 | Windows, patio, painters | Menifee · Riverside County | — | — |
| J R Electric Co | Jesus Severo Rodriguez Briseno | — | (951) 956 8057 | Electricians | Perris · Riverside County | — | — |
| J R Flooring Concepts INC | Tony Richard Faisal | — | (714) 278 0617 | Other | Corona · Riverside County | — | — |
| J R General Construction Company | Juan Antonio Reyes | — | (626) 905 4195 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| J R H Consulting And Design | Kenneth Allan Hicks | — | (951) 746 6559 | Electricians | Nuevo · Riverside County | — | — |
| J R P Concrete Contractor | J R P Concrete Contractor | — | (909) 653 7207 | Other | Moreno Valley · Riverside County | — | — |
| J R Pipeline Co INC | Juan Pablo Renteria | — | (951) 940 5090 | Other | Perris · Riverside County | — | — |
| J R Plumbing | J R Plumbing | — | (714) 818 7468 | GC, remodel, ADU | Norco · Riverside County | — | — |
| J R Roofing INC | Juan Ramon Rodriguez | — | (951) 256 6716 | Other roofers | Norco · Riverside County | — | — |
| J R S Plumbing Co | James Richard Scicli | — | (760) 343 1861 | Other | Thousand Palms · Riverside County | — | — |
| J R's Parking Improvement | J R's Parking Improvement | — | (909) 240 4126 | Other | Perris · Riverside County | — | — |
| J Randolph DBA J&j Contracting | Joshua Randolph Enriquez | — | (310) 357 5545 | GC, remodel, ADU | Mountain Center · Riverside County | — | — |
| J Reglazing | Esteban Juan Diego Pablo | — | (951) 207 8926 | Other | Moreno Valley · Riverside County | — | — |