| KSP Bygg AS | Construction | 2023 |
| Ksu Property AS | Real estate | 2022 |
| KSV Ventilasjon- Og Eiendom- Service, Kihlstadius Og Siljebæk Da | Construction | 2007 |
| KSW Invest AS | | 2021 |
| KT Eiendom AS | Real estate | 2014 |
| KT Kapitalforvaltning AS | Financial services | 2017 |
| KTC AS | | 2018 |
| Kthu AS | | 2021 |
| KTK Holding AS | | 2021 |
| KTM Consulting AS | Professional & scientific | 2019 |
| Ktorg AS | | 2021 |
| KTP Holding AS | Real estate | 2018 |
| KTP Holding I AS | Real estate | 2018 |
| KTP Holding II AS | Real estate | 2018 |
| KTP Holding III AS | Real estate | 2013 |
| KTP Invest AS | Real estate | 2018 |
| KTR Holding Group AS | Financial services | 2018 |
| KTS Invest AS | Other services | 1978 |
| KTS Transport AS | Transport & logistics | 2023 |
| KTV Invest AS | | 2026 |
| KTV Prosjekt AS | Real estate | 2017 |
| Kty Holding AS | | 2021 |
| Kuami Ltd Nuf | Information & communication | 2009 |
| Kubalibre AS | Real estate | 2009 |
| Kuban Industry Park AS | Real estate | 2015 |
| Kube Energy AS | Administrative & support | 2016 |
| Kuben 62 + AS | Health & social care | 2011 |
| Kuben Prosjekt AS | Real estate | 1997 |
| Kubero AS | | 2025 |
| Kubik Interiørarkitekter AS | Professional & scientific | 2012 |
| Kubikgruppen AS | | 2022 |
| Kuboa AS | Education | 2015 |
| Kubon Capital AS | | 2020 |
| Kubona AS | | 2019 |
| Kudasai Holding AS | Professional & scientific | 2020 |
| Kudasai Subsidiary AS | Professional & scientific | 2020 |
| Kudos Møbelservice AS | Other services | 2025 |
| Kuehne + Nagel AS | Transport & logistics | 1990 |
| Kuenheim AS | | 2026 |
| Kugan Studio AS | Transport & logistics | 2016 |
| Kuhle Consulting AS | Professional & scientific | 2021 |
| Kuhlmann & Leuchter AS | Manufacturing | 2012 |
| Kuica AS | Other services | 2021 |
| Kukraft AS | Energy | 2018 |
| Kuks Investment AS | Construction | 2019 |
| Kul Film AS | Information & communication | 2025 |
| Kula Capital AS | | 2018 |
| Kula Invest AS | Financial services | 2006 |
| Kuldrage AS | | 2020 |
| Kulesko Holding AS | | 2021 |
| Kulgai AS | Professional & scientific | 2021 |
| Kuli Co AS | Construction | 2023 |
| Kulimport Eiendomsutvikling II AS | Real estate | 2023 |
| Kulinarisk Akademi AS | Education | 2018 |
| Kulinarisk Akademi Varemerke AS | Education | 2018 |
| Kuling Båt AS | Manufacturing | 2021 |
| Kullerød Eiendom AS | Real estate | 2000 |
| Kullmann Holding AS | Manufacturing | 2002 |
| Kullt AS | Hospitality | 2016 |
| Kulpåsen AS | Real estate | 1997 |
| Kulseth Holding AS | Information & communication | 2007 |
| Kulsrud Holding AS | | 2026 |
| Kulsrud Skog AS | Wholesale & retail | 1979 |
| Kult Byrå AS | Information & communication | 2016 |
| Kultur I Gamle Oslo AS | Arts & recreation | 2015 |
| Kultur Konsulenter AS | Professional & scientific | 2014 |
| Kultur Landsbyer AS | Administrative & support | 2001 |
| Kultur.No Da | Professional & scientific | 2000 |
| Kulturakademiet AS | Education | 2007 |
| Kulturbarna AS | Education | 2010 |
| Kulturbutikk AS | Professional & scientific | 2018 |
| Kulturdrops AS | Information & communication | 2014 |
| Kulturell Dialog Da | Administrative & support | 1999 |
| Kulturell Kapital AS | | 2026 |
| Kulturen AS | Information & communication | 2019 |
| Kulturhallene Eiendom AS | Real estate | 2009 |
| Kulturhuset I Oslo AS | Hospitality | 2012 |
| Kulturimperiet AS | Information & communication | 2026 |
| Kulturkapital AS | Professional & scientific | 2026 |
| Kulturkjellerns Venner SA | Wholesale & retail | 2018 |
| Kulturkultur AS | Professional & scientific | 2024 |
| Kulturmakerne Da | Professional & scientific | 2007 |
| Kulturmeglerne AS | Information & communication | 2021 |
| Kulturminnehjelp AS | Education | 2019 |
| Kulturparken Fus Barnehage AS | Education | 2018 |
| Kulturplakatene Da | Professional & scientific | 1998 |
| Kulturplan AS | Professional & scientific | 2013 |
| Kultursatsing AS | Real estate | 2017 |
| Kulturselskapet AS | Arts & recreation | 2016 |
| Kultursjokk Events AS | Arts & recreation | 2026 |
| Kulturstudier AS | Education | 1997 |
| Kulturterapeutene Da | Professional & scientific | 2000 |
| Kulturvarsling AS | Information & communication | 2025 |
| Kulås Eiendom AS | Real estate | 2003 |
| Kulås Utvikling AS | Real estate | 2014 |
| Kuma Norge AS | Wholesale & retail | 2018 |
| Kumar in Vest AS | | 2023 |
| Kumar-Kiblawi AS | Health & social care | 2023 |
| Kumi AS | Hospitality | 2017 |
| Kumi Oslobukta AS | Hospitality | 2021 |