| Kitex Holding AS | Manufacturing | 2005 |
| Kjøkkelvik Utvikling AS | Real estate | 2016 |
| Kjøraas Bil AS | Other services | 1996 |
| KKJ AS | | 2018 |
| KKP Holding AS | Financial services | 2018 |
| Kleven Trading Ans | | 1991 |
| Klevtech AS | Other services | 2019 |
| Klistr AS | Information & communication | 2014 |
| KMS Arkitekter AS | Professional & scientific | 1986 |
| Knockout Media AS | Information & communication | 2026 |
| Knudstadveien 11 AS | Real estate | 2018 |
| Knut Langaas AS | Construction | 2006 |
| Knut Langaas Eiendom AS | Real estate | 2019 |
| Knute Eiendom AS | Real estate | 2007 |
| Kobe Invest AS | Manufacturing | 2023 |
| Kobe Utemiljø AS | Manufacturing | 2023 |
| Kodial Babycare AS | Wholesale & retail | 1990 |
| Kodial Business AS | Real estate | 2008 |
| Kodial Company AS | Real estate | 2005 |
| Kodial Eiendom AS | Real estate | 2005 |
| Kodial Management AS | Real estate | 2021 |
| Kommandør Otto AS | Construction | 2019 |
| Kompetansehuset AS | Real estate | 1988 |
| Komposium Utvikling AS | Professional & scientific | 2016 |
| Kongeveien 73 AS | Manufacturing | 1972 |
| Kongeveien 75 AS | Real estate | 2026 |
| Kongeveien 79 AS | Construction | 2011 |
| Kongsberg Discovery AS | Manufacturing | 2022 |
| Kongsberg Norcontrol AS | Manufacturing | 1998 |
| Kongstein Eiendom AS | Transport & logistics | 2011 |
| Kongstein Holding AS | Transport & logistics | 2010 |
| Kongstein Transport AS | Transport & logistics | 2010 |
| Konsulentgruppen AS | Professional & scientific | 1997 |
| Koushan AS | Other services | 2021 |
| Kramek AS | Manufacturing | 2004 |
| Kramek Eiendom AS | Real estate | 2005 |
| Krane Invest Ans | Wholesale & retail | 2011 |
| Kristina Klinikken AS | Health & social care | 2017 |
| Kristine & Tones Frisør AS | Other services | 2012 |
| Kroa Vår AS | Hospitality | 2013 |
| Kronborg Technologies AS | Manufacturing | 2016 |
| KSB Holding AS | Professional & scientific | 2005 |
| KSC AS | Wholesale & retail | 1998 |
| Kurserne Da | Education | 2010 |
| Kvams Glass AS | Manufacturing | 1983 |
| Kvartal 29 AS | Real estate | 2011 |
| Kvikk Ollebakken AS | Real estate | 1964 |
| Kåa Invest AS | Real estate | 2005 |
| Kåre Eriksen Renholdstjenester AS | Administrative & support | 2020 |
| La Salle De Danse Horten AS | Education | 2019 |
| Labeli AS | Information & communication | 2016 |
| Laber Invest AS | Wholesale & retail | 1991 |
| Landfall AS | | 2020 |
| Langdøla Invest AS | Professional & scientific | 2001 |
| Langelo Holding AS | Construction | 2005 |
| Langgrunn Næringsutvikling AS | | 2005 |
| Langgrunnveien AS | Real estate | 2014 |
| Langmyra 8 AS | Real estate | 2008 |
| Langni AS | Real estate | 2020 |
| Lapback AS | Information & communication | 2008 |
| Lege Espen Røkaas AS | Health & social care | 2009 |
| Lege Kees Ihlhaug AS | Health & social care | 2023 |
| Leida Design AS | Professional & scientific | 2024 |
| Leieboder AS | Real estate | 2008 |
| Leif Welding AS | Real estate | 2009 |
| Leja Holding AS | Professional & scientific | 2024 |
| LHS Cosmetics AS | Wholesale & retail | 2020 |
| Lics AS | Financial services | 2013 |
| Lilaas AS | Manufacturing | 2011 |
| Lilaas Holding AS | Manufacturing | 1977 |
| Liland Entreprenad | Construction | 1999 |
| Linden Park Frisør AS | Other services | 2021 |
| Linden Tannklinikk AS | Health & social care | 2010 |
| Line Becker AS | Professional & scientific | 2016 |
| Linneaholding AS | | 2021 |
| Liset Holding AS | | 2025 |
| Litle AS | Professional & scientific | 2017 |
| LL12 Holding AS | Professional & scientific | 2016 |
| Logegården AS | Real estate | 1999 |
| Logistikk Materiell AS | Professional & scientific | 2023 |
| LONGEVITY-122 AS | Professional & scientific | 2001 |
| Louise's Session AS | Health & social care | 2023 |
| Lpeiendom AS | Real estate | 2024 |
| LPG Horten AS | Wholesale & retail | 2013 |
| Lykke Media AS | Information & communication | 2013 |
| Lyngset Holding AS | Information & communication | 2023 |
| Lyngset Solutions AS | Information & communication | 2023 |
| Lysgård AS | Professional & scientific | 1990 |
| Lytoo AS | Professional & scientific | 2014 |
| Låsesmed E. Haugan AS | Manufacturing | 2011 |
| Løvøya Drift AS | Hospitality | 2013 |
| M Og E Akademier AS | Arts & recreation | 2018 |
| M Riv Og Bygg AS | Construction | 2020 |
| M-Tek Horten AS | Manufacturing | 2005 |
| Maad AS | Manufacturing | 2011 |
| Maccon AS | Professional & scientific | 2020 |
| Mangfoldsterapeutene AS | Health & social care | 2024 |
| Mape Holding AS | | 2020 |
| Maraz Invest AS | | 2024 |
| Markedsinstituttet AS | Professional & scientific | 1992 |