| L M Premium Custom Painting | L M Premium Custom Painting | — | (760) 880 0955 | Windows, patio, painters | Indio · Riverside County | — | — |
| L N A Shutters INC | Alicia Lizardi | — | (951) 742 7864 | Other | Riverside · Riverside County | — | — |
| L N P Electrical Service | Lyle Nafarette Parayno | — | (951) 768 4048 | Electricians | Corona · Riverside County | — | — |
| L O Lynch Quality Wells & Pumps INC | Kenneth Scott Swarthout | — | (951) 654 7724 | Other | San Jacinto · Riverside County | — | — |
| L P Home Maintenance & Remodeling | Mohsen Jasem | — | (951) 290 3121 | Electricians | Winchester · Riverside County | — | — |
| L P Kirby Excavation INC | Robert Dale Kirby | — | (909) 469 2200 | Other | Riverside · Riverside County | — | — |
| L S G Construction Co | Louis Sanford Gariffo | — | (951) 973 1077 | GC, remodel, ADU | Sun City · Riverside County | — | — |
| L&d Concrete Prep | Laddie Lloyd Waller | — | (760) 583 7969 | Other | Temecula · Riverside County | — | — |
| L&s Grading & Paving | Miguel Angel Lopez-Aguilar | — | (951) 456 9179 | Other | Jurupa Valley · Riverside County | — | — |
| L&s National Services INC DBA Five Star Painting | Conrad Eldon Kolba | — | (951) 878 0980 | Windows, patio, painters | Murrieta · Riverside County | — | — |
| La Casa Bella Design INC | Richard Allen Inglis | — | (951) 675 0911 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| La Colmena Construction | Parra Edwing | — | (760) 333 6690 | GC, remodel, ADU | Indio · Riverside County | — | — |
| La Cresta Holdings INC | Steven Lane Fulgham | — | (951) 837 1209 | Other roofers | Murrieta · Riverside County | — | — |
| La Demo INC | German Aguirre | — | (951) 800 3366 | Other | Riverside · Riverside County | — | — |
| La Force Enterprises | John Martin La Force | — | (866) 945 7594 | GC, remodel, ADU | Norco · Riverside County | — | — |
| La Habra Welding INC | Stephen Alan Smith | — | (562) 923 2229 | Other | Corona · Riverside County | — | — |
| La Hacienda Nursery & Landscape INC | James Scott Harrison | — | (760) 342 3427 | Windows, patio, painters | Indio · Riverside County | — | — |
| La Marble & Tile INC | Salvador Obdulio Ajtun Champet | — | (323) 514 6154 | Other | Lake Elsinore · Riverside County | — | — |
| La One Corp | Ditter Uziel Esturban Mendez | — | (424) 409 7499 | Electricians | Riverside · Riverside County | — | — |
| La Paz Landscape Development INC | Jimenez Agustin | — | (760) 327 3357 | Windows, patio, painters | Cathedral City · Riverside County | — | — |
| La Pool & Spa | Anselmo Luis Aguilar Murillo | — | (909) 519 5371 | Pool | Perris · Riverside County | — | — |
| La Quinta | La Quinta | — | (714) 422 4608 | GC, remodel, ADU | Perris · Riverside County | — | — |
| La Quinta Air Conditioning & Heating INC | Steven Anthony Garcia | — | (760) 275 9081 | HVAC | La Quinta · Riverside County | — | — |
| La Quinta Cove Plumbing INC | Arambula Martin | — | (760) 777 9916 | Other | La Quinta · Riverside County | — | — |
| La Quinta Plumbing Solutions INC | Carlos Alberto Jaime | — | (760) 409 2549 | Other | La Quinta · Riverside County | — | — |
| La Roca | Antonio Aldaba Garcia | — | (951) 965 1195 | Other | Hemet · Riverside County | — | — |
| La Roca Construction INC | Bryan Merida | larocaconstruction777@gmail.com | (951) 662 6459 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| La Sierra HVAC Solutions | La Sierra HVAC Solutions | — | (951) 476-1408 | HVAC | Riverside · Riverside County | — | — |
| La Steel Services INC | Manuel Jonathan Cerda | — | (951) 393 2013 | Other | Corona · Riverside County | — | — |
| La Vid Air Balancing Services | Alejandro Saucedo Flores | — | (760) 771 7900 | Other | Bermuda Dunes · Riverside County | — | — |
| Labeld Ink Incorporated | Jonathan Andrew Caban | — | (951) 941 0536 | Other | Moreno Valley · Riverside County | — | — |
| Lackey Grading INC | Lisa Ann Dufresne | — | (951) 587 6000 | Other | Temecula · Riverside County | — | — |
| Lacy Engineering | Lacy Engineering | — | (949) 371 3500 | Other | Rancho Mirage · Riverside County | — | — |
| Lad's Eye Development & Construction Company | Eduardo Lazcano Roldan | — | (714) 493 7807 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Laguna Coast Painting | Laguna Coast Painting | — | (949) 370 1324 | Windows, patio, painters | Riverside · Riverside County | — | — |
| Laguna Falls Custom Pools And Spas INC | John Steven Ruiz | — | (760) 347 8977 | Pool | Indio · Riverside County | — | — |
| Lagunas Electric LLC | Vazquez Jorge Lagunas | junior@lagunaselectric.com | (714) 852 9969 | Electricians | Lake Elsinore · Riverside County | — | — |
| Lake Air INC | David Mark Adams | sales@lakeair.com | (760) 320 2727 | HVAC | Palm Springs · Riverside County | — | — |
| Lake Elsinore Stone INC | Victor Manuel Jaimes Gordiano | — | (951) 226 4130 | Other | Lake Elsinore · Riverside County | — | — |
| Lake Enterprises | John Michael Paulus | — | (951) 591 3323 | GC, remodel, ADU | Lake Elsinore · Riverside County | — | — |