| Kontho Holding AS | Professional & scientific | 2023 |
| Kontho Invest AS | | 2023 |
| Kontigo Consulting AS | Information & communication | 2016 |
| Kontina Holding AS | | 2017 |
| Kontoor HH Enterprises AS | | 2025 |
| Kontoor HH Ventures AS | | 2025 |
| Kontoor Nordic Holdings AS | | 2025 |
| Kontor AS | Real estate | 2022 |
| Kontor-Rek Da | Wholesale & retail | 1988 |
| KONTOR1 Regnskap AS | Professional & scientific | 1981 |
| Kontoret Bjellebø Og Haukalid Ans | | 1988 |
| Kontorfellesskapet Huseby Legesenter Da | Health & social care | 2001 |
| Kontorfellesskapet I Rosenkrantz GATE7 Da | Health & social care | 2022 |
| Kontorfellesskapet I Thunesvei 2 AS | Professional & scientific | 2016 |
| Kontorfellesskapet O20 AS | Real estate | 2025 |
| Kontorfellesskapet Oslo Eiendomssenter AS | Real estate | 1991 |
| Kontorfellesskapet Skøyen AS | Professional & scientific | 2013 |
| Kontorfellesskapet Vinderentorget AS | Real estate | 2006 |
| Kontorpost Ans | Professional & scientific | 2002 |
| Kontorrama AS | Wholesale & retail | 1984 |
| Kontorselskapet AS | Administrative & support | 2008 |
| Kontorspar AS | Wholesale & retail | 1995 |
| Kontra Holding AS | | 2024 |
| Kontrast AS | Professional & scientific | 2005 |
| Kontrast Bolig AS | Real estate | 2019 |
| Kontrast Bolig SPV 1 AS | Real estate | 2020 |
| Kontrast Invest AS | Real estate | 2006 |
| Kontrazt Oslo AS | Professional & scientific | 2023 |
| Kontrol AS | Information & communication | 2025 |
| Kontroll AS | Information & communication | 2019 |
| Kontroll Og Rådgivning AS | Professional & scientific | 2003 |
| Kontroller Regnskap Og Rådgivning AS | Professional & scientific | 2016 |
| Kontrollsmart Nuf | Information & communication | 2010 |
| Kontrollz AS | Information & communication | 2012 |
| Kontur Forlag AS | Information & communication | 2012 |
| Kontxt Film AS | Information & communication | 2012 |
| Konus AS | Wholesale & retail | 1991 |
| Konvall Invest AS | | 2025 |
| Konvallstien 4 Og 6 AS | Real estate | 2019 |
| Konvent Invest AS | Professional & scientific | 2008 |
| Konventveien 35 AS | Real estate | 2021 |
| Konversai AS | Information & communication | 2024 |
| Kookoo AS | Real estate | 2007 |
| Koolio AS | Financial services | 2018 |
| Koolit AS | Professional & scientific | 2018 |
| Koolit Management AS | Administrative & support | 2018 |
| Koop SA | Professional & scientific | 1997 |
| Kooperativet SA | Other services | 2013 |
| Koordina AS | Professional & scientific | 2025 |
| Koordinat AS | Information & communication | 2026 |
| Kopeba Invest AS | Financial services | 2007 |
| Kopi-Senteret Ans | Administrative & support | 1985 |
| Kopkoi Kapital AS | | 2015 |
| Kopperud & Toppe Musikk AS | Arts & recreation | 2022 |
| Kopperud Holdco AS | Real estate | 2015 |
| Koppholen 13 AS | Real estate | 2006 |
| Koppholen 16 AS | Real estate | 2018 |
| Koppholen 20 Holding AS | Real estate | 2020 |
| Kopro Kontrakt- & Prosjektledelse AS | Professional & scientific | 2020 |
| Kopstadkrysset Næringspark AS | Real estate | 2022 |
| Kor Interiørarkitekter AS | Professional & scientific | 2014 |
| Kor Invest AS | Real estate | 2005 |
| Kor Prosjektstyring AS | Professional & scientific | 1994 |
| Korabel AS | | 2022 |
| Korak AS | Professional & scientific | 2006 |
| Korbu Invest AS | Financial services | 2018 |
| Korcyl Team AS | Construction | 2025 |
| Korde AS | Information & communication | 2016 |
| Kordel Consulting AS | Information & communication | 2022 |
| Korea National Oil Corporation | Mining & quarrying | 2011 |
| Korea Research Institute of Ships & Ocean Engineering | Professional & scientific | 2024 |
| Korean Food AS | Hospitality | 2022 |
| Koredu AS | | 2022 |
| Koren AS | Real estate | 2019 |
| Koreo Arkitekter AS | Professional & scientific | 2022 |
| Korinvest AS | Financial services | 2012 |
| Korn Bakeri AS | Manufacturing | 2017 |
| Korn Ferry AS | Administrative & support | 1990 |
| Korn Ventures AS | Arts & recreation | 2017 |
| Koro Capital AS | Financial services | 2011 |
| Korpsbutikken AS | Wholesale & retail | 2000 |
| Korrigan Investment AS | Financial services | 2011 |
| Korsah Technologies AS | Information & communication | 2026 |
| Korsan Holding | Professional & scientific | 2022 |
| Korsbakken Bad AS | Wholesale & retail | 1976 |
| Korsbakken Invest AS | Wholesale & retail | 2005 |
| Korsfest Invest AS | | 2024 |
| Korsfurk AS | | 2026 |
| Korsgaard Holding AS | Administrative & support | 2015 |
| Korsgata 25 Næring AS | Real estate | 2025 |
| Korsgata 25 Oslo AS | Real estate | 2025 |
| Korsgata 29 AS | Real estate | 2025 |
| Korshamn Eftf. AS | Real estate | 1976 |
| Korshavn Consulting AS | | 2022 |
| Korsmo Data AS | Information & communication | 2025 |
| Korsmogranly AS | Information & communication | 2024 |
| Korsnes Holding V AS | | 2020 |
| Korsvik Eiendom AS | Real estate | 2024 |
| Korsvik Holding AS | Real estate | 2016 |
| Korsvik Næringsbygg AS | Real estate | 2008 |