| Figas Construction | Robert Leslie Figas | amkryukov@gmail.com | (707) 442 2620 | Other | Eureka · Humboldt County | — | — |
| Fine Line Construction | David Michael Enos | — | (707) 498 3438 | GC, remodel, ADU | Mc Kinleyville · Humboldt County | — | — |
| Fine Lines General Contracting LLC | Reed Matthew Parsons | — | (707) 273 1209 | GC, remodel, ADU | Bayside · Humboldt County | — | — |
| Fisch Drilling And Pump INC | Christina Ann Fisch | — | (707) 768 9800 | Other | Hydesville · Humboldt County | — | — |
| Fish And Chips Construction | Timothy Paul Johnston | — | (707) 740 5097 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Fitze Quality Construction | Dennis Paul Fitze | — | (707) 498 0086 | GC, remodel, ADU | Hydesville · Humboldt County | — | — |
| Flickinger Enterprises | Jon Taylor Flickinger | — | (707) 407 7845 | GC, remodel, ADU | Cutten · Humboldt County | — | — |
| Focused Design Build | Focused Design Build | — | (707) 502 9360 | GC, remodel, ADU | Mc Kinleyville · Humboldt County | — | — |
| Foi | Robert Charles Mc Beth | — | (707) 822 8800 | HVAC | Arcata · Humboldt County | — | — |
| Foley Electrical | Jeramee Cain Foley | — | (707) 601 2180 | Electricians | Kneeland · Humboldt County | — | — |
| Footprint Construction | Katrina Janeil Schneider | — | (707) 832 9602 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Forbes Cabinets INC | Dyllan Russell Forbes | — | (707) 445 1329 | Other | Eureka · Humboldt County | — | — |
| Foremans Painting | Foremans Painting | — | (707) 601 2005 | Windows, patio, painters | Mc Kinleyville · Humboldt County | — | — |
| Forest Builder 707 | Forest Builder 707 | — | (707) 601 8161 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Forsat Systems | Forsat Systems | — | (707) 768 2149 | Other | Hydesville · Humboldt County | — | — |
| Fortuna Glass INC | Teresa Lynn Lewis | — | (707) 496 0000 | Windows, patio, painters | Fortuna · Humboldt County | — | — |
| Fortuna Plumbing | Fortuna Plumbing | — | (707) 834 0315 | Other | Fortuna · Humboldt County | — | — |
| Foster Striping | Foster Striping | — | (707) 845 9786 | Other | Eureka · Humboldt County | — | — |
| Foundation First Consulting LLC | Abram Ian Fockaert | info@foundation-first-consulting.com | (707) 845 1985 | Electricians | Fortuna · Humboldt County | — | — |
| Frank A Lake | Frank A Lake | — | (707) 601 1961 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Frank Janowski Builders | Frank Janowski Builders | — | (707) 442 4163 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Frank S Zabel Trucking Company INC | Franklin Stanley Zabel | — | (707) 443 4277 | Other | Eureka · Humboldt County | — | — |
| Freestyle Construction | Garyn Anthony Broussard | builder@freestyleconstruction.com | (707) 223 2109 | GC, remodel, ADU | Rio Dell · Humboldt County | — | — |
| Friesen Homes | Nevin Jacob Friesen | — | (707) 725 1999 | GC, remodel, ADU | Fortuna · Humboldt County | — | — |
| Full Circle Garden Solutions | Full Circle Garden Solutions | fullcirclefarmandfood@gmail.com | (530) 557 7683 | Windows, patio, painters | Mc Kinleyville · Humboldt County | — | — |
| G & G Properties Corporation | Dave Benedict Geare | info@ggproperties.com | (707) 382 5704 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| G L Netherby | G L Netherby | — | (707) 498 5997 | Other | Myers Flat · Humboldt County | — | — |
| G M Pavlich Construction INC | Gerald Maurice Pavlich | — | (707) 499 0167 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| G P Omholt Construction | Gregory Paul Omholt | — | (707) 834 2842 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| G R Sundberg INC | Sonja Ann Sundberg | — | (707) 825 6565 | Other | Arcata · Humboldt County | — | — |
| G R Wilcox Enterprises INC | Ray Dean Wilcox | — | (707) 986 7486 | Other | Whitethorn · Humboldt County | — | — |
| G W Construction | Warren Gurden Staley | — | (707) 498 4175 | GC, remodel, ADU | Mc Kinleyville · Humboldt County | — | — |
| G W Petersen Plumbing | G W Petersen Plumbing | — | (707) 834 2208 | Other | Ferndale · Humboldt County | — | — |
| Gabco Pnw INC | Skyler Dane Ober | — | (707) 834 1372 | Other roofers | Fortuna · Humboldt County | — | — |
| Gabriel Lampro's Archangel Builders | Gabriel Lampro's Archangel Builders | — | (707) 825 7663 | GC, remodel, ADU | Bayside · Humboldt County | — | — |
| Garfield Electric | Christopher Lee Garfield | — | (707) 768 1996 | Electricians | Carlotta · Humboldt County | — | — |
| Garrett Langdon Construction | Garrett Wayne Langdon | — | (707) 672 5551 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Gary D Davis INC | Gary Dean Davis | — | (707) 840 0507 | Other | Mc Kinleyville · Humboldt County | — | — |
| Gary D Forbes DBA G D F Builders | G D F Builders | — | (707) 499 9409 | GC, remodel, ADU | Eureka · Humboldt County | — | — |
| Gary Delorme Construction | Gary Joseph Delorme | — | (707) 683 6004 | GC, remodel, ADU | Garberville · Humboldt County | — | — |