| Gasscare AS | Professional & scientific | 2015 |
| Gat-Ship AS | Information & communication | 2005 |
| Gautefalltomter AS | Real estate | 2011 |
| Gbbl Prosjekt AS | Real estate | 2005 |
| Gbinvest AS | | 2024 |
| GBS Holding AS | | 2008 |
| Geberit Service AS | Wholesale & retail | 2005 |
| Geh Drift AS | Construction | 2006 |
| Geh Eiendom AS | Real estate | 2006 |
| Gestione AS | | 2000 |
| Get Work AS | Education | 2024 |
| GG Eiendom 1 AS | Real estate | 2025 |
| GG Golf AS | Administrative & support | 2025 |
| Ghazot Holding AS | | 2025 |
| GHS Fysioterapi AS | Health & social care | 2012 |
| Gisholt Kjøtt & Vilt AS | Wholesale & retail | 2025 |
| Git Nuf | Wholesale & retail | 2010 |
| Gjenskinn Gravminne AS | Professional & scientific | 2016 |
| Gjerpensgate 15 Boligutvikling AS | Real estate | 2018 |
| Gjerpensgate 15 Skien AS | Real estate | 2017 |
| Gjev Invest AS | Real estate | 2012 |
| Gjuvåa Kraftverk AS | Energy | 2019 |
| Gk-Holdco AS | | 2026 |
| GKV23 AS | Real estate | 2020 |
| Gle Invest AS | Wholesale & retail | 2014 |
| Glenn Hellstrand AS | Wholesale & retail | 2016 |
| Glitre Mule AS | | 2021 |
| GM Minilager AS | Real estate | 2011 |
| Godstransport AS | Transport & logistics | 1980 |
| Godstransport Eiendom AS | Real estate | 2022 |
| Good Trade AS | Wholesale & retail | 2010 |
| Gorm AS | Real estate | 2008 |
| Gormebolet AS | Real estate | 2008 |
| Graneng Eiendom AS | Real estate | 2007 |
| Granraude Holding AS | Professional & scientific | 2023 |
| Grava Eiendom AS | Real estate | 2007 |
| Greenstone Solutions Ans | Wholesale & retail | 2013 |
| Gren Holding AS | | 2023 |
| Gren Home AS | Wholesale & retail | 2018 |
| Grenland Asiamat AS | Wholesale & retail | 2015 |
| Grenland Autotech AS | Other services | 2012 |
| Grenland Betong Og Armering Ans | Construction | 1994 |
| Grenland Bilberging AS | Transport & logistics | 2016 |
| Grenland Billakkering AS | Other services | 2019 |
| Grenland Billakkering Eiendom AS | Real estate | 2007 |
| Grenland Blikkenslagerverksted AS | Construction | 2005 |
| Grenland Development AS | Real estate | 2016 |
| Grenland Elektro AS | Construction | 1988 |
| Grenland Energispar AS | Construction | 2022 |
| Grenland Energy Holding AS | Financial services | 2013 |
| Grenland Friteater AS | Arts & recreation | 2000 |
| Grenland Helsepark AS | Real estate | 2021 |
| Grenland Helsesenter AS | Real estate | 2015 |
| Grenland HMS AS | Professional & scientific | 2007 |
| Grenland Holding AS | Construction | 2005 |
| Grenland Industrimuring Eiendom AS | Hospitality | 1992 |
| Grenland Kontoreiendom AS | Real estate | 2021 |
| Grenland Lagerutleie AS | Real estate | 2025 |
| Grenland Leilighetshotell AS | Real estate | 2012 |
| Grenland Lett Og Mett AS | Hospitality | 2018 |
| Grenland Logistikkpark AS | Real estate | 2003 |
| Grenland Maling & Interiør AS | Wholesale & retail | 1997 |
| Grenland Maritime AS | Professional & scientific | 2012 |
| Grenland Multifix Ans | Construction | 2006 |
| Grenland Multiservice AS | Administrative & support | 2019 |
| Grenland Naprapati Porsgrunn AS | Health & social care | 2016 |
| Grenland Omsorg AS | Health & social care | 2023 |
| Grenland Pokerrun AS | Administrative & support | 2025 |
| Grenland Power Hub Ans | Professional & scientific | 2025 |
| Grenland Shipping Agency AS | Transport & logistics | 2010 |
| Grenland Sjakksenter AS | Education | 2018 |
| Grenland Stein & Sølv AS | Wholesale & retail | 1990 |
| Grenland Stillasutleie AS | Administrative & support | 2013 |
| Grenland Taksering AS | Professional & scientific | 2010 |
| Grenland Takservice AS | Construction | 2017 |
| Grenland Taxi AS | Transport & logistics | 1997 |
| Grenland Thaimassasje AS | Other services | 2016 |
| Grenland Trafikkskole AS | Education | 2020 |
| Grenland Truckservice AS | Administrative & support | 2025 |
| Grep Arbeid AS | Health & social care | 2021 |
| Grep Grenland AS | Health & social care | 2006 |
| Grindheim AS | Information & communication | 2018 |
| Grinilia Eiendom AS | Real estate | 1986 |
| Grit Consult AS | Professional & scientific | 2022 |
| Gro's Frisør AS | Other services | 2014 |
| Grubbe Takst Og Bygg AS | Real estate | 2024 |
| Grunnåi Kraftverk AS | Energy | 1996 |
| Grønt Bygg AS | Construction | 2019 |
| GS Stålbygg AS | Construction | 2022 |
| GS Varde Eiendom AS | Construction | 2017 |
| GST Eiendom AS | Real estate | 2026 |
| GST Tannlege AS | Health & social care | 2026 |
| Guldbrand Eiendom AS | Real estate | 2005 |
| Guldbrand Holding AS | Real estate | 2005 |
| Gullsmed Neerbye AS | Wholesale & retail | 2000 |
| Gullsmed Pettersen & Snoek AS | Wholesale & retail | 2004 |
| Gulløy AS | | 2025 |
| Gulv & Malerkompaniet AS | Construction | 2002 |
| Gumpens Auto Grenland AS | Other services | 1965 |
| Gunder Solvesen Eiendom AS | Real estate | 2023 |