| Itq IT Services AS | Information & communication | 2025 |
| Iwona Og Franz Holding AS | | 2020 |
| Ixtabox AB Nuf | | 2026 |
| J&O Entreprenør AS | Construction | 2022 |
| J.B Company AS | Professional & scientific | 2017 |
| Ja Byggpro AS | Construction | 2023 |
| Jafema AS | Professional & scientific | 2007 |
| Jaff Kjøttsenter Asker AS | Wholesale & retail | 2019 |
| Jahe 856 Holding AS | | 2023 |
| Jakob Grøstad Holding AS | | 2026 |
| Jalmar Nest AS | Health & social care | 2023 |
| James Grieve AS | Wholesale & retail | 2021 |
| Jamope Holding AS | | 2020 |
| Jassta AS | Professional & scientific | 2021 |
| Javnin Invest AS | | 2025 |
| JB Aase Holding AS | | 2020 |
| Jcjl Invest AS | | 2020 |
| Jemma Invest AS | Financial services | 2015 |
| Jensen Consulting AS | Professional & scientific | 2023 |
| Jentene Da | Administrative & support | 1988 |
| Jernsletten Advisory Service AS | Professional & scientific | 2020 |
| Jhold AS | | 2025 |
| JMB Elektro AS | Construction | 2026 |
| JN Rørservice AS | Construction | 2012 |
| Jobbagent AS | | 2013 |
| Jodacare AS | Information & communication | 2026 |
| Jodapro AS | Professional & scientific | 2019 |
| Joe Silver Digitalisering AS | Manufacturing | 2013 |
| Johan Peter Torgersen AS | | 2008 |
| Johan Skaaret Holding AS | Financial services | 2012 |
| Johanc Holding AS | | 2020 |
| Johns Wind Windows AS | Professional & scientific | 2026 |
| Joj Holding AS | | 2020 |
| Jones Invest AS | Real estate | 2005 |
| Jones Lang Lasalle Services AS | Real estate | 2008 |
| Jorica Invest AS | Financial services | 2013 |
| Josie AS | Real estate | 2015 |
| Josr AS | Health & social care | 2020 |
| Jovitas Permanent Makeup AS | Other services | 2020 |
| Joyberg Invest AS | Real estate | 2016 |
| Joymount AS | Professional & scientific | 1999 |
| Joyn AS | Information & communication | 2020 |
| JPK Invest 1 AS | Real estate | 2022 |
| Js-Power Technology AS | Professional & scientific | 2021 |
| Juelma Invest AS | | 2024 |
| Juleni AS | Financial services | 2008 |
| Juven Dagligvare AS | Wholesale & retail | 2009 |
| Jøa AS | Construction | 2007 |
| Jørgen På Jordet AS | Construction | 2017 |
| Jørgensen Rådgivning AS | Professional & scientific | 2015 |
| K-Trykk Bjellebø & Haukalid Ans | Wholesale & retail | 1991 |
| K2 Facility AS | Administrative & support | 2015 |
| Kaapstad AS | Real estate | 2020 |
| Kaare Hanevold Gartneri Ans | Real estate | 1993 |
| Kabelgata AS | | 2024 |
| Kald Beregning AS | Professional & scientific | 2010 |
| Kalsvarden AS | Real estate | 1985 |
| Kampen Mot Hodet AS | Education | 2024 |
| Kanalveien 66 AS | Real estate | 2012 |
| Kanuto Holding AS | Financial services | 2005 |
| Kappa Finans AS | Real estate | 2005 |
| Kaprifol AS | Financial services | 2008 |
| Karat Invest AS | Real estate | 2007 |
| Kariola Invest AS | | 2020 |
| Karloz Invest AS | | 2023 |
| Karltinden AS | Real estate | 1999 |
| Kaushik Holding AS | Hospitality | 2021 |
| Kavli Resources AS | Professional & scientific | 2018 |
| Kavlico AS | Professional & scientific | 2014 |
| Kayaskårner AS | Hospitality | 2024 |
| Kea Zhang AS | Information & communication | 2018 |
| Kenron AS | Agriculture & fishing | 2020 |
| Kentaur Norge AS | Wholesale & retail | 2002 |
| Keramikkverkstedet Asker AS | Education | 2025 |
| Kew 588 Holding AS | | 2023 |
| Ki Power Engineering AS | Professional & scientific | 2023 |
| Kiiltoclean AS | Wholesale & retail | 2009 |
| Kilfors Invest AS | Financial services | 2016 |
| Kilfors Investment AS | | 2017 |
| Kinetics Norge AS | Professional & scientific | 1994 |
| Kirkegata 23-25 AS | Real estate | 2010 |
| Kirkegata 23-25 Holding AS | Real estate | 2018 |
| Kirkeveien 54 AS | Information & communication | 2014 |
| Kiropraktisk Center Sandvika AS | Health & social care | 2006 |
| Kiropraktor Sascha a Elsner AS | Health & social care | 2022 |
| Kiropraktor Thue AS | Health & social care | 2023 |
| Kis Bidco AS | | 2024 |
| Kis Holding AS | Manufacturing | 2021 |
| Kis Midco AS | Manufacturing | 2024 |
| Kis Norge AS | Manufacturing | 2012 |
| Kitchen Expert Nuf | Construction | 2018 |
| Kitchenline AS | Wholesale & retail | 2011 |
| Kiønig AS | Real estate | 1996 |
| Kjedelig Holding AS | Information & communication | 2022 |
| Kjellesvik Reservoir Management Services AS | Professional & scientific | 2005 |
| Kjerne IT AS | Information & communication | 2024 |
| Kjæstad Holding AS | | 2022 |
| Kjøkken Konsulenten Nor-Pol Da | Wholesale & retail | 2004 |
| Kjøpslåven AS | Real estate | 2003 |
| KK Beholdning AS | | 2025 |