| Ivar Endresen Eiendom AS | | 2025 |
| Ivar Næring AS | Water & waste | 1998 |
| Ivaretatt AS | Administrative & support | 2013 |
| Ivarjord AS | | 2024 |
| Ivaro AS | | 2026 |
| Ivas Norge AS | Professional & scientific | 2017 |
| Iversen Holdings AS | | 2020 |
| Iverson Efuels AS | Manufacturing | 2021 |
| Ivi Consulting AS | Professional & scientific | 2016 |
| Ivito Da | Wholesale & retail | 2010 |
| Ivolv AS | Information & communication | 2021 |
| Ivy Ante AS | Professional & scientific | 2019 |
| Izomax AS | Mining & quarrying | 2022 |
| J & J Invest AS | Financial services | 2005 |
| J Johnsen & Sønner AS | Manufacturing | 1987 |
| J Kapital AS | Financial services | 2013 |
| J Tveterås AS | Financial services | 1998 |
| J&E Holding AS | Health & social care | 2021 |
| J&J Aarrestad Holding AS | Financial services | 2005 |
| J. Bjorheim AS | Arts & recreation | 2024 |
| J. Steen Holding AS | | 2021 |
| J.A Auto AS | Other services | 2025 |
| J.R.R Invest AS | | 2023 |
| J.Solgård Holding AS | | 2025 |
| J3EA Holding AS | | 2023 |
| J3EA Ventures AS | | 2022 |
| Ja-Ho AS | Real estate | 2007 |
| Jackson Holding AS | Financial services | 2016 |
| Jackventure AS | | 2024 |
| Jacobsen AS | Professional & scientific | 2023 |
| Jacobsen Rør AS | Construction | 2012 |
| Jadarholm AS | Real estate | 1969 |
| Jadarhus AS | Construction | 1994 |
| Jadarhus Bygg AS | Construction | 2007 |
| Jadarhus Gruppen AS | Construction | 2008 |
| Jadarr AS | | 2024 |
| Jade Investments AS | Financial services | 2015 |
| Jaeger Vision AS | Real estate | 2022 |
| Jafs AS | | 2023 |
| Jagu Invest AS | | 2021 |
| Jai Hind Indisk Restaurant AS | Hospitality | 2014 |
| Jain Invest AS | Financial services | 2007 |
| Jaja Thai Mat AS | Hospitality | 2022 |
| Jakobs Brød AS | Manufacturing | 2014 |
| Jakobsen Administrasjon AS | Real estate | 2012 |
| Jakobsen Consulting Stavanger AS | Professional & scientific | 2015 |
| Jakobsen Regnskap Ars. Da | Professional & scientific | 2015 |
| Jakt, Fiske, Kunst & Kultur AS | Arts & recreation | 2018 |
| Jammerdalen Da | Arts & recreation | 2022 |
| Jan E. Dahle Holding AS | Wholesale & retail | 2005 |
| Jan Egil Nærland AS | Education | 2005 |
| Jan Oftedal Holding AS | Wholesale & retail | 2024 |
| Jan Øyvind Pedersen Dagligvare AS | Wholesale & retail | 2020 |
| Jan-Arne Hagen Veterinærtjeneste AS | Professional & scientific | 2016 |
| JAN9 AS | Financial services | 2014 |
| Janaflaten 24 AS | Manufacturing | 2012 |
| Janas Fiskerøkeri AS | Manufacturing | 2017 |
| Jane Holding AS | | 2025 |
| Janne Holding AS | Financial services | 2010 |
| Jansen Gilje Invest AS | Real estate | 1997 |
| Jansson & Larsen Regnskap AS | Professional & scientific | 1998 |
| Januar Holding AS | Professional & scientific | 2008 |
| Janus AS | Financial services | 2014 |
| Janux Ventures AS | | 2021 |
| Japex Norge AS | Mining & quarrying | 2019 |
| Jardin Foya Blanca SA | Households | 1999 |
| Jarkap AS | | 2025 |
| Jarnor AS | | 2025 |
| Jarvi AS | | 2021 |
| Jasa Medical AS | Professional & scientific | 2014 |
| Jasi AS | Wholesale & retail | 2005 |
| Jatho AS | | 2024 |
| Jatora AS | Professional & scientific | 2017 |
| Jawad Haug Holding AS | Wholesale & retail | 2023 |
| Jaysound Invest Aksjeselskap | Information & communication | 2022 |
| JB Invest AS | Construction | 2006 |
| JBS Inneklima AS | Construction | 2018 |
| JBV Eiendom AS | Real estate | 2025 |
| Jde AS | | 2026 |
| Jeco Invest AS | Financial services | 2011 |
| Jeg Management AS | Real estate | 2014 |
| Jek-Invest AS | | 2006 |
| Jekteberg Nessa Fysio- Og Manuellterapi AS | Health & social care | 2025 |
| Jelsagata 24 AS | Wholesale & retail | 2018 |
| Jemaf AS | Health & social care | 2023 |
| Jenergy AS | Manufacturing | 2018 |
| Jennings Holding AS | | 2025 |
| Jens Zetlitz Gate 47 Bygg AS | Real estate | 2025 |
| Jens Zetlitzgt. 47 AS | | 2025 |
| Jensen Eiendom & Investering AS | Real estate | 2020 |
| Jensen Nordic Holding AS | | 2025 |
| Jentegym Stavanger AS | Arts & recreation | 2026 |
| Jepron AS | Professional & scientific | 2021 |
| Jepson Holding AS | Information & communication | 2015 |
| Jeroboam AS | Financial services | 2018 |
| Jess Holding AS | | 2022 |
| Jetgrunn AS | Real estate | 2012 |
| Jeti AS | | 2025 |
| Jeykey AS | | 2007 |
| JGN Capital AS | | 2026 |