| Jarndahl AS | | 2023 |
| Jarne AS | | 2022 |
| Jarnholt Invest AS | | 2023 |
| Jaro Eiendom Invest AS | Real estate | 2007 |
| Jaro Eiendomsutvikling AS | Real estate | 2013 |
| Jaro Invest AS | Real estate | 2021 |
| Jaro Prosjekt AS | Real estate | 2007 |
| Jarosen Holding AS | | 2024 |
| Jarry Holding AS | | 2019 |
| Jarslett Invest AS | Real estate | 2007 |
| Jartind Holding AS | Financial services | 2005 |
| Jarvang AS | | 2021 |
| Jas Beauty AS | Other services | 2020 |
| Jas Kapital AS | Professional & scientific | 2022 |
| Jas Venture AS | Wholesale & retail | 2022 |
| Jaske Pluss AS | Construction | 2019 |
| Jasmin AS | Hospitality | 2022 |
| Jaspeke AS | Professional & scientific | 2020 |
| Jassal Eiendom AS | Real estate | 2003 |
| Jassi Sushi AS | Hospitality | 2022 |
| Jasta AS | | 2026 |
| Jatek AS | Professional & scientific | 1996 |
| Jatek Bygg AS | Professional & scientific | 2024 |
| Jatlijak AS | Real estate | 2018 |
| Jatta AS | Wholesale & retail | 2021 |
| Jattajatta Eiendom AS | Real estate | 2025 |
| Java AS | | 2021 |
| Java Espressobar & Kaffeforretning AS | Hospitality | 2004 |
| Javabin Økonomi AS | Administrative & support | 2007 |
| Javad El Bakali AS | Arts & recreation | 2026 |
| Javatec AS | Information & communication | 1997 |
| Javel AS | | 2022 |
| Javelin (Norway) Investments Ltd Nuf | Professional & scientific | 2018 |
| Javelin Advokatfirma AS | Professional & scientific | 2016 |
| Javelin Corporate Services AS | Professional & scientific | 2016 |
| Javelin Finance (Norway) Ltd Nuf | Professional & scientific | 2013 |
| Javi-Group AS | Information & communication | 2024 |
| Javico AS | Transport & logistics | 2026 |
| Javid Invest AS | | 2026 |
| Javier Talens Holding AS | | 2020 |
| Javik AS | Health & social care | 2024 |
| Javino AS | Professional & scientific | 2009 |
| Javita AS | Real estate | 2012 |
| Javita Eiendom AS | Real estate | 2025 |
| Javo Varmeservice AS | Construction | 2018 |
| Jaw AS | | 2022 |
| Jawa Holding AS | | 2025 |
| Jawad Butikkdrift AS | Wholesale & retail | 2024 |
| Jawe Ans | Professional & scientific | 2009 |
| Jaweb.Dev Da | Information & communication | 2024 |
| Jawel Da | Information & communication | 2025 |
| Jawendel Invest AS | | 2021 |
| Jawendel Sea Products AS | | 2004 |
| Jawiha AS | Professional & scientific | 2007 |
| Jawiz AS | Information & communication | 2026 |
| Jaws AS | | 2024 |
| Jax Offshore AS | | 2011 |
| Jaxus AS | Wholesale & retail | 2014 |
| Jay Asset Management AS | Professional & scientific | 2021 |
| Jay Capital AS | Professional & scientific | 2021 |
| Jay Invest AS | Health & social care | 2016 |
| Jay O Invest AS | Other services | 2016 |
| Jayas AS | Professional & scientific | 2023 |
| Jayfive Invest AS | | 2025 |
| Jaylink Consulting AS | Professional & scientific | 2021 |
| Jays Holding AS | | 2022 |
| Jaz Patralex AS | | 2024 |
| Jaza Capital AS | | 2026 |
| Jazid Collective AS | Information & communication | 2001 |
| Jazz AS | Arts & recreation | 2019 |
| Jazz Invest AS | Real estate | 2014 |
| Jazzlab Holding AS | Information & communication | 2020 |
| Jazzlab Tech AS | Information & communication | 2021 |
| Jazzland AS | Arts & recreation | 2001 |
| JB Aure Holding AS | | 2021 |
| JB Coaching AS | Education | 2026 |
| JB Maling AS | Construction | 2021 |
| JB Mur&Bygg AS | Construction | 2020 |
| JB Nordby Invest AS | Real estate | 2015 |
| JB Snekkerservice AS | Construction | 2022 |
| JB SPV AS | | 2020 |
| JB Ventures AS | Financial services | 2017 |
| Jb-H Invest AS | | 2020 |
| Jb.Eiendom AS | Real estate | 2007 |
| Jba Holding AS | Financial services | 2016 |
| Jbakery AS | Manufacturing | 2024 |
| JBB Holding AS | | 2023 |
| Jbb-Invest AS | Real estate | 2011 |
| JBF Bank Og Forsikring Holding AS | Financial services | 2025 |
| JBF Forsikring AS | Financial services | 1895 |
| JBF Sparebank AS | Financial services | 2000 |
| JBG 13 AS | Real estate | 2015 |
| JBG 14B Holding AS | Real estate | 2022 |
| JBG Regnskap AS | Professional & scientific | 2024 |
| Jbhm AS | Professional & scientific | 2015 |
| Jbi AS | Wholesale & retail | 2023 |
| Jbit AS | Information & communication | 2015 |
| JBK AS | | 2018 |
| JBK Holdco AS | | 2026 |
| JBK Motor Invest AS | Financial services | 2005 |