| Fm-Eiendom AS | Real estate | 2011 |
| Fo-Tec AS | Manufacturing | 2016 |
| Foh Holding AS | | 2024 |
| Foliereklame Skien AS | Professional & scientific | 2022 |
| Follow AS | Hospitality | 2019 |
| Follow Merci AS | Hospitality | 2025 |
| For Future Invest AS | Real estate | 2003 |
| For Nature AS | Information & communication | 2019 |
| Forces AS | Construction | 2019 |
| Forestal Bygg AS | Construction | 2012 |
| Forland Eiendom AS | Wholesale & retail | 2007 |
| Forland Utvikling AS | Manufacturing | 2007 |
| Formue Invest AS | Real estate | 2006 |
| Fortuna Park AS | | 2018 |
| Fortunakvartalet AS | Real estate | 2005 |
| Fossum Sol 1 AS | Energy | 2023 |
| Fossumgata 8 Holding AS | | 2025 |
| Fotograf Renate Madsen AS | Professional & scientific | 2023 |
| Foxcastle AS | Real estate | 2017 |
| FPF Skien AS | Arts & recreation | 2026 |
| FR. Stangsgt. 2 AS | Professional & scientific | 2013 |
| Frank Jenssen Korrosjonsteknikk AS | Manufacturing | 1990 |
| Frederiko Holding AS | | 2024 |
| Frederiko Invest AS | | 2024 |
| Fredlaus Holding AS | | 2023 |
| Frednes Invest AS | Manufacturing | 2005 |
| Fredrik Nordraaks AS | Financial services | 2005 |
| Fredøy AS | Construction | 2018 |
| Fredøy Gruppen AS | Professional & scientific | 2024 |
| Freshno Holding AS | Real estate | 2016 |
| Fridbe Holding AS | | 2020 |
| Frier Havn AS | Real estate | 1989 |
| Frier VVS AS | Construction | 2021 |
| Friherre AS | Construction | 2012 |
| Frii AS | Wholesale & retail | 2017 |
| Friisma AS | Financial services | 2015 |
| Fris Holding AS | Real estate | 2011 |
| Frisk Sandefjord AS | Health & social care | 2016 |
| Fristad Forvaltning AS | | 2023 |
| Frisør Berge AS | Other services | 2001 |
| Frisør Larsen AS | Other services | 2000 |
| Frisørene På Lie AS | Other services | 2013 |
| Frium & Scheie AS | Real estate | 2013 |
| Frium & Scheie Drift AS | Real estate | 2018 |
| Frium Holding AS | Manufacturing | 2005 |
| Frode Bjønnes Transport AS | Transport & logistics | 2019 |
| Frodes Montasje & Vedlikehold AS | Construction | 2012 |
| Frogner AS | Wholesale & retail | 2000 |
| Frogner Hovedgård AS | Real estate | 2021 |
| Frognerhagen AS | | 2025 |
| Fryda AS | Manufacturing | 2022 |
| Frydenberg Holding AS | Real estate | 2015 |
| Frydentopp AS | Real estate | 1998 |
| Frøya Bil AS | Wholesale & retail | 2026 |
| Frøya Bygg&Eiendom AS | Construction | 2024 |
| Frøya Life AS | | 2019 |
| Frøya Naturprodukter AS | Wholesale & retail | 2001 |
| FTB Invest AS | Financial services | 2015 |
| Furuheim Bygg Og Eiendom AS | Real estate | 2009 |
| Furuseth Gård Skien AS | Real estate | 2007 |
| Future Field Energy AS | Professional & scientific | 2022 |
| Futurevac AS | Professional & scientific | 2018 |
| Fyr Forvaltning AS | Administrative & support | 2025 |
| Fyrtårnet AS | Professional & scientific | 2025 |
| Færaas Elektro AS | Construction | 2024 |
| Færevik Eckholdt AS | Professional & scientific | 2026 |
| Første Gir Da | Professional & scientific | 2023 |
| G & C Eiendom AS | Real estate | 2010 |
| G Coward Grubbe Terasse AS | Real estate | 1974 |
| G Kristiansen Eiendom AS | Real estate | 2020 |
| G Kristiansen Holding AS | Manufacturing | 2020 |
| G-Takst AS | Professional & scientific | 2013 |
| G. Coward AS | Wholesale & retail | 1980 |
| G. J. H. Å. Investment AS | | 2014 |
| G.A Eiendom AS | Real estate | 2020 |
| G/F Holding AS | | 2025 |
| Ga Consulting AS | Professional & scientific | 2013 |
| Gaaren Service AS | Wholesale & retail | 2011 |
| Gablers Undertøysalong AS | Wholesale & retail | 2020 |
| Galleri Aas AS | Administrative & support | 1988 |
| Galleri Valen Kragerø AS | Wholesale & retail | 2024 |
| Gamle Skien AS | Hospitality | 2019 |
| Gamle Union Brug Antikk AS | Wholesale & retail | 2011 |
| Gap Eiendom AS | Real estate | 2021 |
| Gap Invest AS | Financial services | 2011 |
| Garage 15 AS | Wholesale & retail | 2011 |
| Garantert Renhold AS | Administrative & support | 2023 |
| Gartner'N AS | Administrative & support | 2017 |
| Garvik Holding AS | Wholesale & retail | 2014 |
| Garvoll Holding AS | Professional & scientific | 2021 |
| Gas AS | | 2022 |
| Gba Prosjekt- Og Anleggsledelse AS | Professional & scientific | 2025 |
| Geir Gundersen Transport AS | Transport & logistics | 2012 |
| Geiteryggen Cafe AS | Hospitality | 1993 |
| Geitryggen Hangar 5 Da | Transport & logistics | 2022 |
| Gemellus Holding AS | | 2026 |
| Gentlemen's Corner AS | Other services | 2024 |
| Geo Trade AS | Professional & scientific | 2015 |
| Geotek AS | Professional & scientific | 1977 |
| Getrichordietryin AS | Professional & scientific | 2025 |