| John's Asphalt & Sealcoating INC | John Joseph Georgeovich | — | (626) 665 0101 | Other | Moreno Valley · Riverside County | — | — |
| Johnathan Evans | Johnathan Evans | — | (949) 637 8804 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Johnathan Ryan Bailey | Johnathan Ryan Bailey | — | (951) 206 8193 | Other | Riverside · Riverside County | — | — |
| Johnathan Sotelo | Johnathan Sotelo | — | (909) 660 1494 | GC, remodel, ADU | Beaumont · Riverside County | — | — |
| Johnny Electric | Christopher James Bristow | johnnyelectric@cox.net | (949) 208-0271 | Electricians | Riverside · Riverside County | — | — |
| Johnny Electric INC | John Francis White | johnnyelectric@cox.net | (949) 208-0271 | Electricians | Temecula · Riverside County | — | — |
| Johnny Junior Quiroz | Johnny Junior Quiroz | — | (951) 902 9655 | GC, remodel, ADU | Romoland · Riverside County | — | — |
| Johnny Mean | Johnny Mean | — | (909) 342 8612 | Other | Hemet · Riverside County | — | — |
| Johnny R Geer DBA Alternative Fire Protection | Alternative Fire Protection | — | (951) 906 2190 | Other | Canyon Lake · Riverside County | — | — |
| Johnson Built | Amia Michele Johnson | — | (951) 572 8458 | GC, remodel, ADU | Menifee · Riverside County | — | — |
| Johnson Custom Build INC | Pakie Vincent Jr Plastino | info@johnsoncustombuild.com | (415) 298 2774 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| Johnson Electric | Peter Timothy Johnson | — | (951) 378 7811 | Electricians | Sun City · Riverside County | — | — |
| Johnson Electrical Services | Stephen James Johnson | — | (951) 347 5215 | Electricians | Riverside · Riverside County | — | — |
| Johnson Floor Co | Dominic Roman Johnson | — | (909) 994 4497 | Other | Corona · Riverside County | — | — |
| Johnson Integrity Construction | Keith Thomas Johnson | — | (951) 783 8054 | GC, remodel, ADU | Eastvale · Riverside County | — | — |
| Johnson Mechanical | Brent Mathew Johnson | — | (760) 393 1373 | Other | Palm Desert · Riverside County | — | — |
| Johnson Refrigeration INC | Michael Lee Heflin | johnrefriginc@yahoo.com | (760) 922 5124 | HVAC | Blythe · Riverside County | — | — |
| Johnson's Mechanical | Johnson's Mechanical | — | (951) 470 9700 | HVAC | Norco · Riverside County | — | — |
| Johnstone Construction Co | Jayson James Johnstone | — | (909) 747 7054 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Jokaia Electric | Ortega Jesus | — | (951) 675 2080 | Electricians | Riverside · Riverside County | — | — |
| Jon Davis HVAC | Jon Davis HVAC | service@jondavishvac.com | (951) 764 2257 | HVAC | Temecula · Riverside County | — | — |
| Jon Downs Desert Finish Company | Jonathan Wayne Downs | — | (760) 636 2782 | GC, remodel, ADU | Indio · Riverside County | — | — |
| Jon Martin | Jon Martin | — | (951) 796 9229 | Pool | Hemet · Riverside County | — | — |
| Jon Medina Electric LLC | Jon Mike Medina | — | (951) 801 1933 | Electricians | Riverside · Riverside County | — | — |
| Jon Minney Construction LLC | Jongabriel Minney | — | (951) 370 5366 | GC, remodel, ADU | Lake Elsinore · Riverside County | — | — |
| Jon Reise | Jon Reise | — | (951) 452 0781 | HVAC | Riverside · Riverside County | — | — |
| Jon Slivick Construction | Jonathan Eli Slivick | — | (209) 304 8860 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Jon's Electric | Jonathan Maxwell Azpell | — | (626) 240 9181 | Electricians | Palm Desert · Riverside County | — | — |
| Jonathan Arredondo | Jonathan Arredondo | — | (760) 424 6220 | Electricians | Desert Hot Springs · Riverside County | — | — |
| Jonathan Basiger Construction | Jonathan Frederick Basiger | — | (951) 526 7450 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| Jonathan Dinco Electric | Dinco Jonathan | — | (760) 698 2672 | Electricians | Blythe · Riverside County | — | — |
| Jonathan Duffy DBA Duffy Home Works | Duffy Home Works | — | (951) 795 5692 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Jonathan William Bloom | Jonathan William Bloom | — | (951) 490 7253 | Windows, patio, painters | Wildomar · Riverside County | — | — |
| Jones Bros Construction Company | Michael Clyde Jones | — | (760) 347 2891 | Other | Coachella · Riverside County | — | — |
| Jones Construction | Eric Paul Jones | — | (760) 861 2966 | Other | Coachella · Riverside County | — | — |
| Jones Construction | Bradley Wayne Jones | — | (760) 881 2442 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Jones Construction Services | Dean Raymond Jones | jonesconstructionservices1@gmail.com | (909) 223 2370 | GC, remodel, ADU | Moreno Valley · Riverside County | — | — |
| Jones Heating And Air Conditioning | Jones Heating And Air Conditioning | — | (951) 529 0169 | HVAC | Riverside · Riverside County | — | — |
| Jones Jack Edward | Jones Jack Edward | — | (760) 469 3208 | Other | Rancho Mirage · Riverside County | — | — |
| Jonny Socket Electrical And HVAC | Jonathon Odell Sudduth | — | (909) 721 7467 | HVAC | Desert Center · Riverside County | — | — |