| Robert G Love Construction | Robert Gregory Love | — | (530) 320 9213 | GC, remodel, ADU | Susanville · Lassen County | — | — |
| Roseberry Residential Tree Service | Roseberry Craig | — | (530) 816 0450 | Tree | Westwood · Lassen County | — | — |
| Ruben Gerardo Molina | Ruben Gerardo Molina | — | (530) 310 0277 | Windows, patio, painters | Susanville · Lassen County | — | — |
| Russ Smith Plumbing | Russ Smith Plumbing | — | (530) 339 6094 | Other | Standish · Lassen County | — | — |
| Rutily's Woodworks | Rutily's Woodworks | — | (707) 485 2639 | GC, remodel, ADU | Susanville · Lassen County | — | — |
| Ryken Roofing | Michael James Ryken | — | (707) 357 4825 | Other roofers | Bieber · Lassen County | — | — |
| S R Averill Electrical | Scott Richard Averill | — | (530) 251 6564 | Electricians | Susanville · Lassen County | — | — |
| Safeguard Electric | Darian John Weaver | darianweaver@safeguard-electric.com | (530) 251 7050 | Electricians | Susanville · Lassen County | — | — |
| Schortz Enterprise | Schortz Enterprise | — | (530) 310 3130 | GC, remodel, ADU | Janesville · Lassen County | — | — |
| Scott Killgore Flooring | Scott Killgore Flooring | — | (530) 251 7432 | Other | Susanville · Lassen County | — | — |
| Scott's Electric | Aaron Christopher Scott | — | (530) 774 5958 | Electricians | Lake Almanor · Lassen County | — | — |
| Sd's Concrete | Sd's Concrete | — | (530) 526 2879 | Other | Susanville · Lassen County | — | — |
| Seamless Restoration Services | Seamless Restoration Services | — | (408) 394-0043 | Restoration | Vista · Lassen County | — | — |
| Sean Bitle Turf & Irrigation | Sean Bitle Turf & Irrigation | — | (530) 310 0194 | Windows, patio, painters | Standish · Lassen County | — | — |
| Settin' In Tile | Settin' In Tile | — | (530) 251 7899 | Other | Lake Almanor · Lassen County | — | — |
| She Paints | She Paints | — | (707) 771 5566 | Windows, patio, painters | Susanville · Lassen County | — | — |
| Short Stack Masonry | Short Stack Masonry | — | (530) 249 3913 | Other | Susanville · Lassen County | — | — |
| Sierra Oaks | Sierra Oaks | — | (530) 682 5238 | GC, remodel, ADU | Susanville · Lassen County | — | — |
| Silkwood Septic LLC | Dillon Bryce Silkwood | — | (530) 249 1481 | Other | Susanville · Lassen County | — | — |
| Sisemore Construction | Zachary Edmond Sisemore | — | (530) 409 8700 | GC, remodel, ADU | Lake Almanor · Lassen County | — | — |
| Sky High Roofing | Matthew David Tinston | — | (530) 257 9093 | Other roofers | Susanville · Lassen County | — | — |
| Smith Electric | Brian Earl Smith | — | (530) 680 8911 | Electricians | Lake Almanor · Lassen County | — | — |
| Smith's Pumps INC | Brett Mason Smith | smithspumps@hotmail.com | (530) 252 4420 | Other | Susanville · Lassen County | — | — |
| Stanley Electric | Stanley Electric | — | (707) 683-2451 | Electricians | Northridge · Lassen County | — | — |
| Steele Remodeling | Steele Remodeling | — | (530) 816 0851 | GC, remodel, ADU | Susanville · Lassen County | — | — |
| Steve Church Construction | Steve Eugene Church | — | (530) 386 7447 | GC, remodel, ADU | Lake Almanor · Lassen County | — | — |
| Stoneco Construction INC | Larry Lee Standiford | — | (530) 257 4506 | HVAC | Susanville · Lassen County | — | — |
| Stoneco Contracting INC | Larry Lee Standiford | — | (530) 257 4506 | HVAC | Susanville · Lassen County | — | — |
| Stoneside Blinds & Shades Solana Beach | Stoneside Blinds & Shades Solana Beach | — | (619) 935-0905 | Windows, patio, painters | Solana Beach · Lassen County | — | — |
| Sun Shine Construction | Steven Richard Sr Shafe | — | (775) 690 4794 | GC, remodel, ADU | Janesville · Lassen County | — | — |
| Sunlight Home Construction | Sunlight Home Construction | — | (818) 515-7308 | GC, remodel, ADU | Northridge · Lassen County | — | — |
| Susanville Refrigeration | Susanville Refrigeration | — | (530) 257 5257 | HVAC | Susanville · Lassen County | — | — |
| The Wire Wizard | The Wire Wizard | thewirewizardca@gmail.com | (530) 353 7077 | Electricians | Westwood · Lassen County | — | — |
| Thompson Peak Construction | Tucker Dalton Rhyn | — | (530) 249 4909 | GC, remodel, ADU | Janesville · Lassen County | — | — |
| Tim Allen Construction | Timothy Wayne Allen | — | (760) 915 0051 | GC, remodel, ADU | Standish · Lassen County | — | — |
| Timber And Stone Builders | Timber And Stone Builders | — | (530) 250 7240 | GC, remodel, ADU | Susanville · Lassen County | — | — |
| Timbersmith Construction | Dustin Michael Smith | — | (530) 260 0885 | GC, remodel, ADU | Milford · Lassen County | — | — |
| Trails West Garage Doors | Jonathan Earl Schrock | — | (530) 260 8123 | GC, remodel, ADU | Litchfield · Lassen County | — | — |
| Treece Construction LLC | Boyd Scott Treece | — | (530) 310 3290 | Electricians | Lake Almanor · Lassen County | — | — |
| Tri County Pump Co | Lawrence Dexter Cravy | — | (530) 310 0644 | Other | Susanville · Lassen County | — | — |