| JGN Holding AS | | 2020 |
| JH Vestre Invest AS | | 2023 |
| Jhfinvest AS | Financial services | 2018 |
| JHP Bygg AS | Construction | 2016 |
| JHS AS | | 2021 |
| Jiao Xie Senter for Kinesisk Kultur Og Språk AS | Education | 2012 |
| Jibcam Ans | Administrative & support | 2007 |
| Jihu Invest AS | | 2026 |
| Jinor AS | Financial services | 2014 |
| Jippi Group AS | | 2026 |
| Jippi Univers AS | Education | 2026 |
| Jivamukti Yoga AS | Education | 2019 |
| Jivanmukta AS | Real estate | 2005 |
| JJ Consulting AS | Professional & scientific | 2025 |
| JJ Eiendom AS | Real estate | 1980 |
| JJ Finans AS | | 2023 |
| JJ Gruppen AS | Real estate | 2016 |
| JJ Kapital AS | Real estate | 1980 |
| Jjvr AS | Professional & scientific | 2026 |
| Jke Design Forus AS | Wholesale & retail | 2017 |
| JKM Holding AS | Real estate | 2005 |
| JKM Invest AS | | 2021 |
| JKV AS | Financial services | 2013 |
| JLB Tech AS | | 2026 |
| JM Consult AS | Real estate | 1989 |
| JMK Unlimited AS | Professional & scientific | 2024 |
| JMP Media AS | Information & communication | 2018 |
| Jnhj AS | | 2022 |
| Jo Consult AS | Professional & scientific | 2025 |
| Joan a Castro AS | Wholesale & retail | 2000 |
| Joanno AS | | 2023 |
| Joars AS | Wholesale & retail | 2002 |
| Joars Butikkdrift AS | Wholesale & retail | 2019 |
| Joavegen 40 AS | Real estate | 2012 |
| Job Arkitekter AS | Professional & scientific | 1992 |
| Job Holding AS | Real estate | 2015 |
| Jobba Jobba Jobba 2023 AS | | 2023 |
| Jobba Jobba Jobba AS | | 2022 |
| Jobe Da | Wholesale & retail | 1999 |
| Jobe Invest AS | | 2024 |
| Jochma Invest AS | Education | 2021 |
| Joda Horizon AS | Real estate | 2026 |
| Jofib AS | Financial services | 2017 |
| Jofo AS | Real estate | 2001 |
| Jogga Invest AS | Financial services | 2012 |
| Joh Mæhle & Co Holding AS | | 2014 |
| Joh Rasmussen & Racine AS | Real estate | 1871 |
| Joha AS | | 2020 |
| Joha Norge Nuf | Wholesale & retail | 2000 |
| Johan Gismarvik Maskin AS | Construction | 2020 |
| Johan Holding AS | Administrative & support | 2005 |
| Johan P Johnsen AS | Wholesale & retail | 1961 |
| Johan Stangeland Eiendom AS | Real estate | 1999 |
| Johan Sverdrup Eiendom Da | Real estate | 2017 |
| Johan Tveit AS | Real estate | 1946 |
| Johan Vu Holding AS | | 2024 |
| Johannes Helgø AS | Financial services | 2005 |
| Johansen Pianoteknikk AS | Other services | 2020 |
| Johleo AS | Professional & scientific | 2016 |
| John Arild Haugsgjerd Invest AS | Financial services | 2005 |
| John Haugvaldstad AS | Construction | 1988 |
| John Svela Holding AS | Real estate | 2005 |
| Johnsen Investering AS | | 2021 |
| Joi Eiendom AS | Real estate | 2005 |
| Joinas AS | Administrative & support | 2021 |
| Joinswell AS | Information & communication | 2022 |
| Joka AS | Real estate | 1998 |
| Joka Investering AS | Professional & scientific | 2006 |
| Jokerhus Bygg AS | Construction | 1995 |
| Joko Holding AS | | 2020 |
| Jolang AS | Real estate | 1978 |
| Jollychimp AS | Arts & recreation | 2024 |
| Jolt Holding AS | Real estate | 2011 |
| Joltama AS | Real estate | 2002 |
| Jomabi AS | Real estate | 2007 |
| Jomeli AS | Real estate | 2013 |
| Jomeli Invest AS | | 2024 |
| Jomon AS | Information & communication | 2014 |
| Jon Geir Tengesdal AS | | 2019 |
| Jon Harstad AS | | 2024 |
| Jon Torbergsonsvei 8 AS | Real estate | 2015 |
| Jonas Forsman B | Health & social care | 2009 |
| Jonas H Meling AS | Wholesale & retail | 1980 |
| Jonas Halsne Holding AS | | 2025 |
| Jonas Hansen Haugsvær AS | Professional & scientific | 2024 |
| Jonas Thor AS | Professional & scientific | 2022 |
| Jone Heggheim Holding AS | | 2024 |
| Jonibo Invest AS | | 2026 |
| Jonnymackaronny AS | Professional & scientific | 2024 |
| Jonnypop Arkitektur AS | Professional & scientific | 2026 |
| Joon Records Norway AS | Information & communication | 2025 |
| Jordskjelv AS | Information & communication | 2018 |
| Jorna AS | | 2023 |
| Jornokse Holding AS | Health & social care | 2024 |
| Jornokse Manuellterapi AS | Health & social care | 2024 |
| Jorvik Capital AS | Real estate | 2016 |
| Joso Holding AS | | 2024 |
| Joss Production Services Ltd | Professional & scientific | 2019 |
| Jostein Hauge AS | Professional & scientific | 2018 |
| Jostein Holgersen AS | | 2025 |