| Jblom AS | Information & communication | 2005 |
| JBN Holding AS | Professional & scientific | 2004 |
| Jbo Service AS | Wholesale & retail | 2023 |
| JBP Invest AS | Information & communication | 2022 |
| Jbr-Holding AS | Financial services | 2015 |
| JBT Finans AS | Real estate | 2016 |
| JBT Holdingselskap AS | Professional & scientific | 2026 |
| JBW AS | Wholesale & retail | 2016 |
| JBW Invest AS | Real estate | 2009 |
| JC Anlegg AS | Construction | 2022 |
| JC Elektro & Design AS | Construction | 2017 |
| JC Interest AS | Financial services | 2006 |
| JC Kvanvik Holding AS | Real estate | 2007 |
| JC Pedersen AS | Other services | 2024 |
| JC Rosenlund Invest AS | | 2024 |
| JC Tech Invest AS | | 2022 |
| Jca AS | Hospitality | 2020 |
| JCB Group AS | Professional & scientific | 2021 |
| Jcdecaux Norge AS | Professional & scientific | 1996 |
| JCF AS | Professional & scientific | 2007 |
| JCF Investments AS | Real estate | 2025 |
| JCG AS | Financial services | 2005 |
| JCH AS | | 2016 |
| JCL AS | | 2018 |
| Jcloud AS | Information & communication | 2010 |
| JCP Arena AS | Professional & scientific | 2017 |
| JCP Travel AS | Administrative & support | 2012 |
| Jcxp Holding AS | | 2024 |
| JD Future AS | Information & communication | 2025 |
| JD Kosmetisk AS | Health & social care | 2026 |
| JD Kvitvang Holding AS | | 2021 |
| JD Mini Market AS | Wholesale & retail | 2024 |
| JDB Invest AS | | 2024 |
| JDK Holding AS | Real estate | 2018 |
| JDL Holding AS | Professional & scientific | 2015 |
| JDL Invest AS | | 2024 |
| JDM Holdings AS | Information & communication | 2017 |
| Jdo Invest AS | | 2026 |
| Jds-Invest AS | Financial services | 2007 |
| JDS19 AS | Hospitality | 2019 |
| Je Bolig AS | Real estate | 2024 |
| Je Eriksen AS | Financial services | 2017 |
| Je Properties AS | Real estate | 2017 |
| Je Suis Jørgen AS | Information & communication | 2019 |
| Je Svendsen Holding AS | | 2021 |
| Jeab AS | | 2018 |
| Jean Bidco AS | | 2024 |
| Jean Cleanco AS | | 2024 |
| Jean Midco AS | | 2024 |
| Jean-Hansen AS | Financial services | 2011 |
| Jeanette Hauge AS | | 2020 |
| Jeanettes Fristelser AS | Hospitality | 2025 |
| Jeaney AS | Financial services | 2008 |
| Jeb Links AS | Health & social care | 2008 |
| Jeb Prosjekt AS | | 2025 |
| Jeba Eiendom AS | Real estate | 2026 |
| Jebarek AS | Financial services | 2006 |
| Jebek AS | Professional & scientific | 1993 |
| Jebsen Asset Management AS | Financial services | 2005 |
| Jebsen Junior Invest AS | Transport & logistics | 2004 |
| Jebsen Ventures AS | Financial services | 2016 |
| Jec AS | | 2018 |
| Jec Holding AS | | 2016 |
| Jec Invest AS | | 2022 |
| Jecon AS | Professional & scientific | 2014 |
| Jed Agnes AS | | 2023 |
| Jed AS | Financial services | 2013 |
| Jedk AS | Financial services | 2005 |
| Jedson AS | Health & social care | 1965 |
| Jedy Holding AS | | 2021 |
| Jeea Invest AS | | 2022 |
| Jeeves Holding AS | Wholesale & retail | 2020 |
| Jeey AS | | 2023 |
| Jef Heldal Invest AS | | 2020 |
| Jef Invest AS | Real estate | 1996 |
| Jefa AS | Financial services | 1994 |
| Jeffreys AS | Other services | 2026 |
| Jeffreys Tech AS | Wholesale & retail | 1964 |
| Jeg Care AS | Health & social care | 2024 |
| Jeg Fant Jeg Fant Ans | | 1990 |
| Jeg Holding AS | Financial services | 2014 |
| Jeg Invest AS | Real estate | 2020 |
| Jeg Kan Ingenting Om Vin AS | Information & communication | 2025 |
| Jegerberget AS | Financial services | 2015 |
| Jegerhaugen AS | | 2005 |
| Jegerveien 4 AS | Real estate | 2019 |
| Jegerveien Boligutvikling AS | Real estate | 2014 |
| Jegh AS | Financial services | 2005 |
| Jeginor AS | Professional & scientific | 2012 |
| Jegr AS | Financial services | 2008 |
| Jehehe AS | | 2026 |
| Jehs Holding AS | | 2025 |
| Jeisteca AS | Professional & scientific | 2000 |
| Jej Invest AS | Real estate | 2017 |
| Jejo Sport & Capital AS | Real estate | 2005 |
| Jejune Ans | Arts & recreation | 2021 |
| Jek AS | Wholesale & retail | 2006 |
| Jek Oslo Holding AS | Hospitality | 2022 |
| Jek Venture AS | | 2022 |
| Jeka Invest AS | Financial services | 2005 |