| Jarle Sætra AS | Construction | 2000 |
| Jen AS | Real estate | 2017 |
| Jennys Parfyme Ans | | 1991 |
| Jeppes Holding AS | Hospitality | 1997 |
| JMS. Invest AS | | 2022 |
| JMT Gruppen Aps | Construction | 2003 |
| Joakim Engedalen AS | Construction | 2023 |
| Joeman AS | | 2024 |
| Johannsen AS | Real estate | 2015 |
| Johansen Trafikkskole AS | Education | 2001 |
| John Bommen AS | Financial services | 2017 |
| Jonas Bråthen AS | Real estate | 2019 |
| Jondalen Holding AS | Construction | 2024 |
| Jondalsveien 470 AS | Real estate | 2025 |
| Jonsknuten Da | Hospitality | 2007 |
| Jonsroa Agritech AS | Professional & scientific | 2018 |
| Jonsroa Holding AS | Professional & scientific | 2018 |
| Jote Eiendom AS | Real estate | 2014 |
| Jowa Norge AS | Wholesale & retail | 1993 |
| Jowi Eiendom AS | Professional & scientific | 2018 |
| Joyel Consulting AS | Information & communication | 2020 |
| JR Holding Kongsberg AS | Wholesale & retail | 2008 |
| JS Group AS | | 2025 |
| Jt-Dev AS | Information & communication | 2022 |
| JURIST1 AS | Professional & scientific | 2023 |
| Jusa Invest AS | Real estate | 2021 |
| Just Nails AS | Other services | 2020 |
| Juvet Holding AS | | 2023 |
| Jørlu AS | Financial services | 2005 |
| Jørn Paus Invest AS | | 2011 |
| K F Holding AS | Manufacturing | 2022 |
| K-Finn AS | Professional & scientific | 2023 |
| K-S Bad & VVS AS | Construction | 2015 |
| K1 Service AS | Construction | 2023 |
| Kaasa JR. Holding AS | | 2025 |
| Kahe Eiendom AS | Real estate | 2004 |
| Kajander Motor AS | Wholesale & retail | 2015 |
| Kakle AS | Wholesale & retail | 2016 |
| Kampestad AS | Real estate | 2026 |
| Kampklar AS | Education | 2026 |
| Kanitt AS | Professional & scientific | 2021 |
| Kanteføll AS | Information & communication | 2023 |
| Kanton Holding AS | Professional & scientific | 2012 |
| Kargo Invest AS | | 2022 |
| Katma-Consult AS | Professional & scientific | 2014 |
| Katma-Tech AS | Professional & scientific | 2010 |
| KBS Selvvask & Bilpleie AS | Other services | 2024 |
| Keepmoving AS | Information & communication | 2025 |
| Keiflo AS | | 2021 |
| Kenneth Dalen Holding AS | | 2018 |
| Kf-Ehc AS | | 2025 |
| Kif Idrettssenter AS | Real estate | 1987 |
| Kif Klubbhus AS | Real estate | 1999 |
| Kim Andre Haugan AS | | 2023 |
| Kinei AS | Professional & scientific | 2008 |
| Kingsmountain Productions AS | Information & communication | 2015 |
| Kirkegata 20 AS | Real estate | 2022 |
| KIRKEGATA-7 AS | Real estate | 2013 |
| Kirkegårdsveien 50 AS | Real estate | 2022 |
| Kirketorget 5 AS | Health & social care | 2013 |
| Kiropraktor Jørn Espen Bolstad AS | Health & social care | 2021 |
| Kiropraktor Tonny Jensen AS | Health & social care | 2021 |
| Kjeld Rasmussen AS | Financial services | 2017 |
| Kjell Grønboengen AS | Professional & scientific | 1990 |
| Kjell Jørgen Darrud Holding AS | | 2021 |
| Kjell Olaf Sørensen Holding AS | Real estate | 2015 |
| Kjell Ove Sucu Klem AS | Wholesale & retail | 2024 |
| Kjenner Holding AS | | 2026 |
| Kjenås Entreprenør AS | Administrative & support | 2012 |
| Kjeveortoped Marta Habo AS | Health & social care | 2022 |
| Kjeveortoped Silje Enersen AS | Health & social care | 2015 |
| KK Invest AS | | 2023 |
| Klatreveggen Da | Arts & recreation | 2023 |
| Klatreveggen Da | Arts & recreation | 2005 |
| Klemskvartalet Trinn 2 AS | Real estate | 2025 |
| Kleven Holding AS | Information & communication | 2012 |
| KLH Mineral Labratory AS | Professional & scientific | 2017 |
| Klinikk Vestsiden AS | Health & social care | 2012 |
| Klokkerbakken Fysio- Og Manuellterapi AS | Health & social care | 2021 |
| Klokkerbakken Legekontor Da | Health & social care | 2001 |
| Klokkergården AS | Real estate | 1996 |
| Klokseth Eiendom AS | Real estate | 2002 |
| Klyve Kapital AS | | 2025 |
| KMK Invest AS | | 2020 |
| Kmkolstad AS | Information & communication | 2025 |
| KNB12 Ulsteinvik AS | Real estate | 2019 |
| KNB13 Brattvåg AS | Real estate | 2019 |
| Knightec Group Norway AS | Professional & scientific | 2001 |
| Knutefjell AS | Arts & recreation | 2005 |
| Knutehytta AS | Real estate | 1969 |
| Kobberbergsveien 5 AS | Real estate | 2020 |
| KODYN6 AS | Professional & scientific | 2015 |
| Kodyna AS | Professional & scientific | 2016 |
| Kolset AS | Arts & recreation | 2008 |
| Kommisjonsbil AS | Wholesale & retail | 2024 |
| Kon-Text AS | Education | 2014 |
| Kong Dagligvarer AS | Wholesale & retail | 2023 |
| Kong Fu AS | Hospitality | 2022 |
| Kongensgate 2 Kongsberg Holding AS | Real estate | 2022 |
| Kongensgate 3 Kongsberg AS | Real estate | 2021 |