| Karma Clinic AS | Health & social care | 2023 |
| Karol Bygg- AS | Professional & scientific | 2024 |
| Kay a Kristensen Holding AS | | 2018 |
| Kfro Holding AS | | 2021 |
| KG 17 Steinkjer AS | Real estate | 1985 |
| KG 19 Eiendom AS | Real estate | 2000 |
| KG24 Eiendom AS | Real estate | 2018 |
| KG28 Eiendom AS | Real estate | 1939 |
| KG40 Eiendom AS | Real estate | 2015 |
| KH Eiendom Og Invest AS | Real estate | 2015 |
| Kings Corner AS | Hospitality | 2018 |
| Kirkegata 43 Eiendom AS | Real estate | 2023 |
| Kirkegt 2 AS | Real estate | 1963 |
| Kirlad Invest AS | | 2022 |
| Kiropraktor Stig Arthur Hustad AS | Health & social care | 2009 |
| Kiropraktorklinikken 0-100 Steinkjer AS | Health & social care | 2016 |
| Kjell Gundersen Sveiseservice AS | Wholesale & retail | 1998 |
| Kjelvik Mur Og Betong AS | Construction | 2023 |
| Kjentgården AS | Real estate | 2013 |
| Kjerkol Invest AS | Construction | 2021 |
| Kjesbu Fellesfjøs Ans | Agriculture & fishing | 1971 |
| Kjetil Holding AS | Wholesale & retail | 2005 |
| Klaupstad Maskinlag Ba | Agriculture & fishing | 2007 |
| Kleiva AS | Wholesale & retail | 2015 |
| Klepp Maskin Og Transport AS | Construction | 2024 |
| Klimaskog AS | Professional & scientific | 2021 |
| Klingen Vekst AS | Education | 2005 |
| Klinikk Eilen Austli AS | Health & social care | 1998 |
| Klinikk Jensen AS | Health & social care | 2020 |
| Klovika Invest AS | Other services | 2005 |
| Kminsaas AS | Professional & scientific | 2021 |
| Kne Holding AS | Construction | 2005 |
| Knuts Transport AS | Transport & logistics | 1996 |
| Kokkejakker.No AS | Wholesale & retail | 2025 |
| Kolstad Investments AS | Construction | 2015 |
| Kolstad Utleie AS | Administrative & support | 2024 |
| Kongens Gate 27 AS | Real estate | 2008 |
| Kongens Gate 41 AS | Real estate | 2021 |
| Kongensgata 18 AS | Real estate | 2013 |
| Kongensgate 34 AS | Real estate | 2013 |
| Kongensgate 5 Eiendom AS | Real estate | 2019 |
| Konrad Invest AS | Financial services | 1998 |
| Koryol AS | Other services | 2025 |
| Kosli Holding AS | Manufacturing | 2006 |
| Kp-Enterprice AS | Wholesale & retail | 2025 |
| Kreativ AS | Wholesale & retail | 2003 |
| Kreditorforeningen SA | Administrative & support | 1979 |
| Kringla Friluftsbarnehage AS | Education | 2009 |
| Kris Holding AS | Financial services | 2005 |
| Kriscas AS | Financial services | 2018 |
| Kristian Sjøli AS | Construction | 2012 |
| Kuleramma AS | Professional & scientific | 2022 |
| Kultr AS | Professional & scientific | 2021 |
| Kultur Konsortiet AS | | 2025 |
| Kulturgården Bjerkem - Drift AS | Hospitality | 2023 |
| Kulturgården Bjerkem - Eigedom AS | Real estate | 2023 |
| Kundan Gruppen AS | Information & communication | 2015 |
| Kundan Pluss AS | Information & communication | 2024 |
| Kurt Bye AS | Administrative & support | 2000 |
| Kvader AS | Construction | 2025 |
| Kvam Barnehage SA | Education | 1997 |
| Kvam Grendehus SA | Real estate | 1995 |
| Kvam Motell AS | Hospitality | 2011 |
| Kvamslia AS | Real estate | 2016 |
| Kvarving Kommunikasjon AS | Professional & scientific | 2019 |
| Kvernmo Holding AS | Real estate | 1996 |
| Kvitvang Melk Da | Agriculture & fishing | 2006 |
| Kyrre Lønnum Holding AS | | 2026 |
| Kysten Utbygging AS | Real estate | 2000 |
| Kåre Ringseth AS | Mining & quarrying | 1980 |
| L. Gaundal AS | Construction | 2026 |
| La Barca Futura AS | Arts & recreation | 2014 |
| La Femme AS | Other services | 1997 |
| Labog AS | Real estate | 2011 |
| Ladma Invest AS | Financial services | 2005 |
| Lagatun Grendehus SA | Real estate | 1984 |
| Laginvest AS | Other services | 2021 |
| Landbruksauksjon.No AS | Wholesale & retail | 2019 |
| Langeng Invest AS | | 1994 |
| Langtangen AS | Wholesale & retail | 2010 |
| Lar-Aun Holding AS | | 2025 |
| Larol Eiendom AS | Real estate | 2015 |
| Lashlash AS | Other services | 2019 |
| Lasto AS | | 2015 |
| Lavo Eiendom AS | | 2008 |
| Le Marché AS | Wholesale & retail | 2025 |
| Lean Investment AS | | 2025 |
| Lera AS | Information & communication | 1987 |
| Lervik Klinikk AS | Other services | 2025 |
| Levanger Distribusjon AS | Transport & logistics | 2025 |
| LFM AS | Construction | 2024 |
| Lft&M AS | Administrative & support | 2013 |
| LGK Holding AS | | 2016 |
| LHT AS | | 2025 |
| Liceo AS | Health & social care | 2008 |
| Ligna AS | Real estate | 1934 |
| Lille My Hudpleie Og Aromaterapi AS | Other services | 1998 |
| Lille Orion Steinkjer AS | Hospitality | 2015 |
| Lillebrov Invest AS | | 2026 |
| Lillefjell AS | Construction | 2002 |