| Jan Ove Lassesen Holding AS | Wholesale & retail | 2020 |
| Jarl Frisør AS | Other services | 2022 |
| Jawi Invest AS | | 2022 |
| Jero Eiendom AS | Real estate | 1988 |
| Jettrade.No AS | Wholesale & retail | 2019 |
| JHF Eiendom AS | Real estate | 2018 |
| JHV Invest AS | Financial services | 2017 |
| Jilt AS | Other services | 2020 |
| JK Vekst AS | | 2016 |
| Jobbklar Eiendom AS | Health & social care | 2021 |
| Jobbklar Kommune AS | Health & social care | 2021 |
| Jobbklar Norge AS | Health & social care | 2020 |
| Jobbklar Utvikling AS | Health & social care | 1971 |
| John Simonsen Holding AS | Hospitality | 2005 |
| Jordbærpikene Arena AS | Hospitality | 2013 |
| Jordåen Holding AS | | 2020 |
| Jorkjen Eiendom AS | Real estate | 2025 |
| Jorkjen Holding AS | Construction | 2024 |
| Jorkjen MC AS | Other services | 2012 |
| Josephsens Bilberging AS | Transport & logistics | 1983 |
| JP Solutions AS | Information & communication | 2025 |
| JT Bergtun AS | Construction | 2008 |
| JTN Eiendom AS | Real estate | 2020 |
| JTN Holding AS | Real estate | 2019 |
| JTS Tech AS | Information & communication | 2023 |
| Julie Marie Haugen AS | Wholesale & retail | 2026 |
| Justad Invest AS | Wholesale & retail | 2023 |
| Juveler Holding AS | Wholesale & retail | 2001 |
| Jwana Frisør AS | Other services | 2020 |
| Jørgensen Holding AS | Manufacturing | 2010 |
| K Christensen Invest AS | Real estate | 1982 |
| K&B Investment AS | | 2010 |
| K-Aw AS | | 2017 |
| K. Aalerud Invest AS | | 2022 |
| K. Christensen & Co, Moens Båtbyggeri Ans | Arts & recreation | 2005 |
| K. Nor Invest AS | Financial services | 2017 |
| Kaar AS | Financial services | 2017 |
| Kaas Staalbygg Norge AS | Construction | 2011 |
| Kai AS | Education | 2006 |
| Kai Robin Havnaa AS | Arts & recreation | 2016 |
| Kambuzi AS | Information & communication | 2024 |
| Kambuzi Drift AS | Hospitality | 2024 |
| Kanalgården AS | Real estate | 2015 |
| Kanonbra Eiendom AS | Real estate | 2023 |
| Kanonbra Holding AS | Professional & scientific | 2023 |
| Kanonbra Reklame AS | Professional & scientific | 2023 |
| Kapitopp AS | Professional & scientific | 2017 |
| Karl-S Eiendom AS | Real estate | 2018 |
| Karl-S Holding AS | Real estate | 2005 |
| Karo Pharma Invest AS | | 2020 |
| Kastell Tannklinikk AS | Health & social care | 2022 |
| Kathrine Tvermyr AS | Real estate | 2019 |
| Kattehuset AS | Real estate | 2014 |
| Kav AS | Administrative & support | 2018 |
| Kaveh.B AS | Transport & logistics | 2025 |
| KBH Eiendom AS | Real estate | 2022 |
| KC Trading AS | Real estate | 2005 |
| Kest Invest AS | Real estate | 2013 |
| Kgdi Holding AS | Information & communication | 2017 |
| Kick - Byens Beste AS | Arts & recreation | 2014 |
| Kim Monrad Holding AS | | 2022 |
| Kina Laks Eksport AS | | 2007 |
| Kinebrasil AS | Administrative & support | 2009 |
| Kioskdrift Simret AS | Wholesale & retail | 2024 |
| Kirkebakken 5 AS | Real estate | 2011 |
| Kiropraktor Anne Moksness AS | Health & social care | 2015 |
| Kit Holding AS | Hospitality | 2010 |
| KJ Lien Holding AS | | 2023 |
| Kjell Fjell AS | Professional & scientific | 2014 |
| Kjell Johansen Revisjon Ans | Professional & scientific | 1995 |
| Kjerland Eiendom AS | Real estate | 2016 |
| Kjeruben AS | Information & communication | 1992 |
| Kjevekirurgisk Consult AS | Health & social care | 1995 |
| Kjeveortoped Anne Blix Werner AS | Health & social care | 2022 |
| Kjeveortoped Bergman AS | Health & social care | 2017 |
| Kjevik's Gårdsegg Da | Agriculture & fishing | 2010 |
| Kjøkkendrift No 1 Amfi AS | Wholesale & retail | 2011 |
| Kjøkkendrift No 1 Harebakken AS | Wholesale & retail | 2017 |
| Klarmelding AS | Professional & scientific | 2025 |
| Klart Regnskap AS | Professional & scientific | 2021 |
| Kleppe AS | Wholesale & retail | 1989 |
| Klinikk Arendal AS | Health & social care | 2005 |
| Klinikk Stikk Nuf | Health & social care | 2011 |
| Kloppeheia Utvikling AS | Real estate | 2021 |
| Kloppenebakken 10 AS | Real estate | 2023 |
| Kloppenebakken 7 AS | Real estate | 2005 |
| Knerten Service AS | Wholesale & retail | 2016 |
| Knips Event Og DMC AS | Arts & recreation | 2017 |
| Knut a. Høyer Bokhandel AS | Wholesale & retail | 2022 |
| Ko Paulsen Holding AS | | 2026 |
| Ko-Ko Eiendom AS | Real estate | 2008 |
| Kodelauget AS | | 2024 |
| Kollektivterminalen AS | Transport & logistics | 2005 |
| Kolm AS | | 2024 |
| Kolstø Og Grimsland Holding AS | | 2023 |
| Komplett Flytt Og Vask AS | Transport & logistics | 2026 |
| Konsulentfirmaet Heisholt & Nordlie Da | Information & communication | 1999 |
| Kontali Holding AS | Professional & scientific | 2020 |
| Kontebø Invest AS | Financial services | 2006 |
| Kontor Holding AS | Wholesale & retail | 2023 |