| Interhaus AS | Professional & scientific | 1987 |
| Interiør Compagniet Bærum AS | Wholesale & retail | 2017 |
| Intersoft Management Systems AS | Information & communication | 1987 |
| Intrum AS | Administrative & support | 1984 |
| Intrum Capital AS | Financial services | 1990 |
| Intrum Holding Norway AS | Administrative & support | 2008 |
| Intrum Obligations AS | Administrative & support | 1987 |
| Inventum AS | Wholesale & retail | 1999 |
| Investtech Com AS | Financial services | 1997 |
| Invirya AS | | 2024 |
| Ipd Consultant KB | Professional & scientific | 2002 |
| Iph 2 AS | Information & communication | 2007 |
| Ipsas AS | Professional & scientific | 1992 |
| Irute Travel Norway AS | Administrative & support | 2026 |
| Itarken AS | Information & communication | 2023 |
| Itf Internett Trafikk Formidling AS | Information & communication | 2002 |
| Ithac AS | Professional & scientific | 2016 |
| Iveco Norge AS | Wholesale & retail | 1984 |
| J.D. Stigar Invest AS | Real estate | 2019 |
| Jahrklinikken AS | Health & social care | 2022 |
| Jaktlia 1 AS | Real estate | 1946 |
| Jal Holding AS | Real estate | 2013 |
| James Wardman | Construction | 2008 |
| Jekog Invest AS | | 2025 |
| Jem & Fix Norge AS | Wholesale & retail | 2017 |
| Jeras AS | | 2021 |
| Jessheim Stadion Bolig AS | Real estate | 2007 |
| Jessheimtoppen AS | Real estate | 2014 |
| Jinnism Holding AS | Financial services | 2013 |
| Johan Nordström Verktøymaskiner AS | Wholesale & retail | 2019 |
| Johan S. Svendsen AS | Real estate | 2005 |
| John Sisk & Son AS | Real estate | 2026 |
| Joys AS | Professional & scientific | 2026 |
| JTB Holding AS | Professional & scientific | 2018 |
| Jum Holding AS | | 2005 |
| Jusit Advokat AS | Professional & scientific | 2001 |
| Just Technologies AS | Professional & scientific | 2017 |
| Juvo AS | Information & communication | 2017 |
| JV Implenia Stangeland E39 Lyngdal Ans | Construction | 2021 |
| JV Implenia Stangeland E39 Rogfast Ans | Construction | 2023 |
| JV Implenia Stangeland E39 Rogfast E02 Ans | Construction | 2024 |
| K E Weld Ans | | 1989 |
| K11 Investor AS | Real estate | 2018 |
| Kacin AS | | 1999 |
| Kagra IV AS | | 2006 |
| Kala AS | Professional & scientific | 1998 |
| Kamfjord Eiendom AS | Real estate | 2003 |
| Kanfa AS | Mining & quarrying | 2001 |
| Kao Kao Da | Wholesale & retail | 2004 |
| Kapitalhuset Consulting AS | Professional & scientific | 2023 |
| Kari-Nina AS | | 2019 |
| Kartoffel AS | Professional & scientific | 2023 |
| Kav Capital AS | Professional & scientific | 2018 |
| Kav Capital Investment Research AS | Professional & scientific | 2021 |
| KBS Holding AS | Real estate | 2017 |
| KC Offshore AS | Transport & logistics | 2007 |
| KC Offshore Shipco AS | Transport & logistics | 2020 |
| Ke Holding AS | Wholesale & retail | 2005 |
| Kelkoo AS | Information & communication | 1997 |
| Kelkoo Shopping AS | Wholesale & retail | 2022 |
| Kernbo Kernbohrung GmbH | Construction | 2004 |
| Kiham AS | Real estate | 2015 |
| Kilen Eiendom AS | Real estate | 1996 |
| Kilenveien 17-23 AS | Real estate | 2024 |
| King of Shopping AS | Wholesale & retail | 2023 |
| Kinogarasjen AS | Real estate | 2007 |
| Kiro Invest AS | Real estate | 2004 |
| Kistos Energy (Norway) AS | Mining & quarrying | 2017 |
| Kjøleassistanse AS | Construction | 2004 |
| Kobbervikdalen 71 AS | Real estate | 2020 |
| Kolsberg Invest AS | Real estate | 2001 |
| Konekta AS | Administrative & support | 2002 |
| Kongsberg Nemo Pty Ltd | Mining & quarrying | 2012 |
| Kongsberg Renewables Technologies AS | | 2022 |
| Kontroll Elektro AS | Wholesale & retail | 2003 |
| Kontrollvegen 1 AS | Real estate | 2023 |
| Kornsilovegen 88 AS | Real estate | 2020 |
| Korsegården Utvikling AS | Real estate | 2020 |
| Kosmos Eiendom AS | Real estate | 2004 |
| Krbnx AS | Professional & scientific | 2023 |
| Kreativt Bygg AS | Construction | 2017 |
| Krip AS | Real estate | 2005 |
| Krista Hartmann Interiør AS | Professional & scientific | 2011 |
| Krro AS | | 2026 |
| Kruse Smith Entreprenør Øst AS | Construction | 2022 |
| Kruses Gate 9 AS | Real estate | 2015 |
| Ksolutions AS | Information & communication | 2020 |
| Kubberød Invest AS | Real estate | 2019 |
| Kvaerner Contracting Limited | Administrative & support | 2012 |
| Kvikk-Renhold AS | Administrative & support | 2013 |
| Kvitmyra Holding AS | Agriculture & fishing | 2018 |
| Kolsås Senter DA | Real estate | 1990 |
| Kérkyra AS | | 2013 |
| Køde AS | Information & communication | 2022 |
| La Barra Capital AS | Professional & scientific | 2005 |
| Lagårdsveien 44 AS | Real estate | 2007 |
| Lagårdsveien 46 AS | Real estate | 2006 |
| Lagåsen AS | Real estate | 1984 |
| Lakkbar AS | Other services | 2011 |
| Langbrygga 1 AS | Real estate | 2007 |