| Isodren Montasje AS | Construction | 2002 |
| Isrand Invest AS | Wholesale & retail | 2005 |
| Issas Consulting AS | Construction | 2025 |
| Issas Holding AS | | 2018 |
| Isvogna AS | Wholesale & retail | 2026 |
| Iver Holding AS | Financial services | 2005 |
| J.B. Invest AS | | 2025 |
| J.Elgaaen Holding AS | | 2023 |
| Ja Konsulting AS | Professional & scientific | 2006 |
| Jabe Invest AS | Financial services | 2010 |
| Jacob Property Holdings AS | Real estate | 2025 |
| Jaeger-Liteseat AS | Manufacturing | 2014 |
| James Mcgowan Golf AS | Wholesale & retail | 1996 |
| Jansen 1 AS | Construction | 2025 |
| Japp Eiendom AS | Real estate | 1999 |
| Jaqt AS | Manufacturing | 2026 |
| Jeanette Semb AS | Arts & recreation | 2025 |
| Jes Utvikling AS | Real estate | 2011 |
| Jessen Ventures AS | | 2023 |
| Jeweni AS | Real estate | 1998 |
| Jie Invest AS | | 2025 |
| Jim-Holding AS | Education | 2012 |
| Jipp AS | | 2023 |
| Jo La Byggeservice Ans | Construction | 1993 |
| Jobb Agenten AS | Administrative & support | 2016 |
| Jodam Drøbak AS | Hospitality | 2008 |
| Johansen Bygg & Eiendom AS | Construction | 2019 |
| Johnsrud Media AS | Professional & scientific | 2020 |
| Joho Holding AS | Professional & scientific | 2022 |
| Join Invest Ltd Nuf | Information & communication | 2010 |
| Jokerman AS | Financial services | 2012 |
| Jonas Farbu AS | Wholesale & retail | 2023 |
| Jonells Pizza Og Grill AS | Hospitality | 2025 |
| Jordbær Familien AS | Hospitality | 2025 |
| Jordbær Familien Invest Limited Nuf | | 2025 |
| Jtdk AS | Professional & scientific | 2023 |
| JTS Invest AS | Real estate | 2010 |
| Jungo Norway AS | Wholesale & retail | 2012 |
| Jørnsebakken Garasjer AS | Transport & logistics | 2021 |
| K. B. Rådgivning AS | Professional & scientific | 2006 |
| K. Paulsen Eiendom AS | Real estate | 2016 |
| K3 Boligutvikling AS | Real estate | 2016 |
| Kahasas AS | Real estate | 2007 |
| Kakkel & Peis Spesialisten AS | Wholesale & retail | 1992 |
| Kakrel Invest AS | | 2021 |
| Kanutten Invest AS | | 2021 |
| Kashmina AS | Professional & scientific | 2013 |
| Kat Development AS | Professional & scientific | 2005 |
| Kax Holding AS | Water & waste | 2016 |
| KBT Capital Investments AS | | 2026 |
| Keep IT Forever AS | Information & communication | 2020 |
| Kelvin Hughes | Professional & scientific | 2009 |
| Kentos Holding AS | Construction | 2020 |
| Keu AS | Real estate | 2021 |
| Kfi AS | Real estate | 2003 |
| KH Consult AS | Information & communication | 2015 |
| Ki Prosjekt AS | Construction | 2018 |
| Kile Stokholm Arkitekter AS | Professional & scientific | 1998 |
| Kine-M Holding AS | | 2026 |
| Kjeller'N Gaver, Garn Og Hobby AS | Wholesale & retail | 2015 |
| Kjøpe I Norge AS | Professional & scientific | 2023 |
| KKS Holding AS | Real estate | 2005 |
| Klammerfresing AS | Construction | 2022 |
| Klevan Consulting AS | Professional & scientific | 1998 |
| Klimabefuktning AS | Construction | 2025 |
| Klonteig Holding AS | Wholesale & retail | 2022 |
| KLUBBDUGNAD1 AS | Wholesale & retail | 2019 |
| Knuts AS | Real estate | 2019 |
| Koala Consulting AS | Financial services | 2005 |
| Koda Arkitekter AS | Professional & scientific | 2006 |
| Koerts Pengebinge AS | Real estate | 2010 |
| Kofe AS | | 2025 |
| Kohilo AS | | 2019 |
| Kohinoor AS | Health & social care | 2022 |
| Kolbotn Klær Drøbak AS | Wholesale & retail | 2024 |
| Kolbotn Trafikkskole AS | Education | 1985 |
| Kolibri AS | Financial services | 2005 |
| Kolstad Finans AS | | 2025 |
| Kommo AS | Education | 2017 |
| Kompetanseløftet AS | Education | 2016 |
| Kongeveien 220 AS | Real estate | 1998 |
| Konsept Mur & Flis AS | Construction | 2018 |
| Korpeide AS | | 2025 |
| Kosas AS | Professional & scientific | 1996 |
| Krahn Invest AS | Real estate | 2015 |
| Kreativ Eiendomsutvikling AS | Real estate | 2005 |
| Kreativ Holding AS | Professional & scientific | 2005 |
| Krer Holding AS | Construction | 2021 |
| Kresendo Holding AS | | 2024 |
| Kriss Invest AS | Real estate | 1989 |
| Kristina Thomassen | Education | 2013 |
| Kristinejohanneas AS | Hospitality | 2024 |
| Kristoffersen Butikkdrift AS | Wholesale & retail | 2018 |
| Kronborg Resources AS | Professional & scientific | 2012 |
| KSB Norge AS | Wholesale & retail | 1945 |
| Ksce AS | Professional & scientific | 2020 |
| Kva Media AS | Professional & scientific | 2023 |
| Kvaøy AS | Real estate | 2019 |
| Kvernen Consult AS | Professional & scientific | 2018 |
| Kvikkfisk AS | Wholesale & retail | 2007 |