| Johs. Rasmussen Transport AS | Transport & logistics | 2011 |
| Jol Invest AS | Financial services | 2005 |
| Jon Christensen AS | Real estate | 1991 |
| Jon Smørs Vei 7 AS | Real estate | 2016 |
| Jonassen & Co AS | Wholesale & retail | 1978 |
| Jonny Korsnes Holding AS | | 2024 |
| Jordan Invest AS | | 2007 |
| Jordbærpikene Gulskogen AS | Hospitality | 2011 |
| Joreko AS | Administrative & support | 1993 |
| Jose Eiendom AS | Real estate | 1994 |
| Josebo Invest AS | Financial services | 2005 |
| Josefine Da | Wholesale & retail | 1989 |
| Josefsson Holding AS | | 2001 |
| Jostein Folkedal Holding AS | | 2020 |
| Jovialen Drammen AS | Hospitality | 2021 |
| JPJ Bygg AS | Construction | 2010 |
| JPJ Eiendom AS | Real estate | 2014 |
| JPR Vektsystemer AS | Wholesale & retail | 2016 |
| JR Nysæther Invest AS | | 2023 |
| JRS Partners AS | | 2025 |
| JS & SP Rådgivning AS | Financial services | 2020 |
| JSN United AS | Professional & scientific | 2020 |
| JSS Invest AS | Wholesale & retail | 2021 |
| Jube AS | Real estate | 2005 |
| Julian Paris AS | Professional & scientific | 2014 |
| Junite Events AS | | 2022 |
| Jutekompaniet Ans | Wholesale & retail | 2008 |
| Jutulen Invest AS | Wholesale & retail | 2012 |
| Jym AS | Wholesale & retail | 2013 |
| Jyslabra AS | Information & communication | 2013 |
| Jørgen Aasheim Holding AS | | 2021 |
| Jørgen Ellingsen Holding AS | | 2020 |
| Jørgen Moes Gate 4 AS | Real estate | 2018 |
| Jørn Og Rune Automasjon AS | Professional & scientific | 1997 |
| Jørn Og Rune Gruppen AS | Construction | 2005 |
| Jørn Reiersen Holding AS | Wholesale & retail | 2021 |
| Jørnsen Tak AS | Construction | 1994 |
| Jørund Martinsen AS | Wholesale & retail | 1986 |
| K H Engineering AS | Professional & scientific | 2007 |
| K Investering AS | Professional & scientific | 2012 |
| K Og H Holding AS | | 2023 |
| K-Revisor AS | | 2022 |
| K-Sans AS | Administrative & support | 2018 |
| K-Sans Investments AS | Real estate | 2020 |
| K. Christensen AS | Real estate | 2020 |
| K. Green Invest AS | Financial services | 2016 |
| K. Larsen Invest AS | | 2017 |
| K2M Holding AS | | 2026 |
| Ka Møller AS | | 2026 |
| Ka-H Holding AS | | 2025 |
| Kaalsaas Holding AS | | 2021 |
| Kaarstein AS | Health & social care | 2007 |
| Kabelresirk AS | Wholesale & retail | 2021 |
| Kabu Holding AS | | 2018 |
| Kac AS | Health & social care | 2023 |
| Kad Holding AS | Construction | 2015 |
| Kaerly AS | Wholesale & retail | 2021 |
| Kafe` CC Terrassen AS | Hospitality | 2003 |
| Kaffego AS | Manufacturing | 2025 |
| Kaffepunkt AS | Wholesale & retail | 2011 |
| Kafi Eiendom AS | Real estate | 2021 |
| Kagean Holding AS | | 2025 |
| Kairos AS | Administrative & support | 1999 |
| Kajakk Og Fritid AS | Wholesale & retail | 2020 |
| Kaksekollen Holding AS | | 2020 |
| Kalirox AS | Information & communication | 2026 |
| Kallerud Eiendom Og Fritid AS | Real estate | 2021 |
| Kalma Holding AS | | 2005 |
| Kalokai AS | Wholesale & retail | 2026 |
| Kalosjen Eiendom 1 AS | Real estate | 2021 |
| Kalosjen Utvikling AS | Manufacturing | 2021 |
| Kamikaze TM AS | Administrative & support | 2020 |
| Kamille Cafe Vol 2 AS | Hospitality | 2022 |
| Kamstål Øst AS | Manufacturing | 2022 |
| Kanoncon AS | Wholesale & retail | 2016 |
| Kansa Holding AS | | 2026 |
| Kanslergata 10 AS | Real estate | 2015 |
| Kapisol Regnskap AS | Professional & scientific | 2018 |
| Kappa Eiendom AS | Real estate | 2002 |
| Kappcosta AS | Transport & logistics | 2008 |
| Karbis Invest AS | | 2021 |
| Karinsvingen AS | Real estate | 2022 |
| Karl Invest AS | Real estate | 2007 |
| Karma Group AS | Information & communication | 2024 |
| Karma Solutions AS | Information & communication | 2024 |
| Karma Teknikk AS | Professional & scientific | 2019 |
| Karpis Prosjekt AS | Construction | 2026 |
| Kartfjord Elektro AS | Construction | 2025 |
| Kartfjord Holding AS | Construction | 2024 |
| Kaselvig AS | | 2023 |
| Katana Sushi AS | Hospitality | 2012 |
| Katirci Holding AS | Professional & scientific | 2019 |
| Kawa Drammen Invest AS | Hospitality | 2021 |
| Kaymarini AS | Professional & scientific | 2008 |
| KBH Holding AS | Real estate | 2010 |
| KBK Bygg AS | Construction | 2023 |
| KD Renhold AS | Administrative & support | 2026 |
| Kebaco Holding AS | | 2019 |
| Keep IT Liquid AS | | 2022 |
| Keklik Holding AS | Professional & scientific | 2025 |