| Kjempefint AS | Professional & scientific | 2015 |
| Kjempegreit AS | Arts & recreation | 2017 |
| Kjempegreit Produsert AS | Information & communication | 2017 |
| Kjempegreit Show AS | Arts & recreation | 2017 |
| Kjempehjerne AS | Information & communication | 2021 |
| Kjempeholmen Vann Og Avløp Driftsforetak SA | Water & waste | 2021 |
| Kjempetanke Limited | Wholesale & retail | 2026 |
| Kjenn Deg Selv AS | Information & communication | 2011 |
| Kjensli Utvikling AS | Real estate | 2019 |
| Kjenslifeltet AS | Real estate | 2016 |
| Kjentfolk AS | Administrative & support | 2000 |
| Kjeppestadveien 1-3 AS | Real estate | 2021 |
| Kjeppestadveien 2 Eiendom AS | Real estate | 1962 |
| Kjeppestadveien AS | Real estate | 2011 |
| Kjepphest Invest AS | | 2018 |
| Kjernehuset Arkitektkontor AS | Professional & scientific | 2012 |
| Kjernekraft Oslo AS | Education | 2020 |
| Kjernen Invest AS | | 2025 |
| Kjernepar AS | Professional & scientific | 2019 |
| Kjerpeset AS | Health & social care | 2026 |
| Kjerringnes Kraft AS | Energy | 2015 |
| Kjerschow Jevne Invest AS | | 2010 |
| Kjersti K. Vasli AS | Real estate | 2016 |
| Kjersti Nerseth Arkitektkontor AS | Professional & scientific | 2023 |
| Kjerstin Invest AS | | 2021 |
| Kjeråa Kraftverk AS | Energy | 2022 |
| Kjesa AS | Real estate | 2010 |
| Kjetil Aarstein Holding AS | Health & social care | 2020 |
| Kjetil Barvik Invest AS | | 2025 |
| Kjetil Eppeland Holding AS | Financial services | 2018 |
| Kjetil Eriksen Holding AS | | 2014 |
| Kjetil Haugmo AS | Professional & scientific | 2022 |
| Kjetil Larsen Holding AS | | 2016 |
| Kjetil Moen Nettservice AS | Information & communication | 2023 |
| Kjeve-Ansiktskirurgi AS | Health & social care | 2011 |
| Kjeveort AS | Health & social care | 2022 |
| Kjeveortoped Line Minster AS | Health & social care | 2016 |
| Kjeveortoped Sreeram Kumar AS | Health & social care | 2023 |
| Kjeveortoped Steinhäuser-Andresen AS | Health & social care | 2016 |
| Kjeveortoped Tone Olsen Enger AS | Health & social care | 2024 |
| Kjeveortoped Øystein Skogan AS | Real estate | 2009 |
| Kjevi AS | Real estate | 1996 |
| KJF Holding AS | | 2019 |
| KJG Bygg Oslo AS | Construction | 2025 |
| KJH Capital AS | Financial services | 2010 |
| Kjhime Invest AS | | 2023 |
| Kjip Investering AS | | 1965 |
| KJK Holding AS | Real estate | 2008 |
| KJK Invest AS | | 2025 |
| KJK Investering AS | Financial services | 2007 |
| Kjk-Holding AS | Hospitality | 1995 |
| Kjknudsen AS | | 2025 |
| KJL Eiendom AS | Real estate | 2023 |
| KJL Holding AS | Construction | 2022 |
| Kjo 388 Holding AS | | 2023 |
| Kjoi AS | Professional & scientific | 2019 |
| Kjolstad Invest AS | | 2020 |
| Kjonebråten Utvikling AS | Real estate | 2015 |
| Kjuagutt AS | | 2021 |
| Kjul Eiendom AS | Real estate | 2006 |
| Kjulshagen AS | Real estate | 1979 |
| Kjut AS | Information & communication | 2026 |
| Kjuus Invest AS | | 2026 |
| Kjær Eiendom AS | Real estate | 2026 |
| Kjær Invest AS | Information & communication | 2025 |
| Kjær Oslo AS | Wholesale & retail | 2021 |
| Kjærlig AS | Arts & recreation | 2020 |
| Kjærnesveien 72 AS | Real estate | 2019 |
| Kjærnet-Wesseltoft AS | Professional & scientific | 2024 |
| Kjærnsli Holding AS | Financial services | 2005 |
| Kjærnsmo Eiendom AS | Real estate | 1972 |
| Kjærnsmo Invest AS | Real estate | 1924 |
| Kjærnsmo Invest Holding AS | Real estate | 2021 |
| Kjøbenhavns Møbelfabrikker AS | | 2026 |
| Kjøh AS | Arts & recreation | 2022 |
| Kjøkken Og Bar Oslo AS | Hospitality | 2025 |
| Kjøkken Og Elektro AS | Wholesale & retail | 2024 |
| Kjøkken Sjefen AS | Wholesale & retail | 2025 |
| Kjøkkenforhandleren Da | Wholesale & retail | 2009 |
| Kjøkkenkompaniet AS | Wholesale & retail | 2010 |
| Kjøkkenpartner AS | Wholesale & retail | 2017 |
| Kjøkkenskredder Konsulenten AS | Wholesale & retail | 2025 |
| Kjølberggata 27 Seksjon 1 AS | Real estate | 2020 |
| Kjølberggata 29 AS | Real estate | 1998 |
| Kjølberggata 31 AS | Real estate | 2018 |
| Kjølberggaten 21 AS | Real estate | 1996 |
| Kjøle Bra AS | Financial services | 2006 |
| Kjølebil Spesialisten AS | Wholesale & retail | 2021 |
| Kjøling Invest AS | | 2025 |
| Kjøllefjord Vind AS | Energy | 2006 |
| Kjølnesbygg AS | Real estate | 1997 |
| Kjønniksen Holding AS | Professional & scientific | 2020 |
| Kjønstad & Gullerud Varebilene Da | Transport & logistics | 1995 |
| Kjøpesenter Furuset AS | Real estate | 2002 |
| Kjøpesenter Årvoll AS | Real estate | 2011 |
| Kjøpesenterutvikling AS | Administrative & support | 1989 |
| Kjøpmannshuset Butikkdrift AS | Wholesale & retail | 2010 |
| Kjøpmannshuset Norge AS | Administrative & support | 1997 |
| Kjøpmannspartner AS | Administrative & support | 2014 |
| Kjør AS | Transport & logistics | 2016 |