| Kam Invest AS | Financial services | 2005 |
| Kamperhauggata AS | Real estate | 2002 |
| Kan Lyd & Produksjon AS | Information & communication | 2016 |
| Kanthal Norway AS | Manufacturing | 2021 |
| Kanutus AS | Real estate | 1999 |
| Kapital AS | Real estate | 2021 |
| Kapitelberget Natur - Og Kulturbarnehage SA | Education | 1991 |
| Karaffelen AS | Wholesale & retail | 2024 |
| Karen Kristoffersen Holding AS | Health & social care | 2020 |
| Kari Nesse Eiendom AS | Real estate | 2026 |
| Kari Nesse Holding AS | | 2026 |
| Kari Nesse Tannlege AS | Health & social care | 2026 |
| Karimi Holding AS | Administrative & support | 2022 |
| Karma Thai Massasje & Spa AS | Other services | 2015 |
| Karosserifabrikken Byfogd Paus G 5 AS | Real estate | 2013 |
| Kars Klyve AS | Wholesale & retail | 2013 |
| Kars Nenset AS | Wholesale & retail | 2012 |
| Kars Verksted AS | Other services | 2018 |
| Karsten Bygg Og Maskin AS | Construction | 2020 |
| Kateraas Invest AS | Real estate | 1976 |
| Katrine Bakke AS | Health & social care | 2021 |
| Katrine Slettedahl AS | Health & social care | 2026 |
| Kaukus AS | Information & communication | 2019 |
| Kay & Bee Connect AS | Wholesale & retail | 2025 |
| Kay Invest AS | | 2021 |
| Kazan Hotel AS | Hospitality | 2025 |
| KB Maskin AS | Construction | 2006 |
| Keb Consulting AS | Professional & scientific | 2023 |
| Kebab Campino AS | Hospitality | 2011 |
| Kebab Campino Skien AS | Hospitality | 2026 |
| Kebe AS | Hospitality | 2018 |
| Kebony AS | Professional & scientific | 2012 |
| Kebony Norge AS | Manufacturing | 1997 |
| Keepsmiling AS | Information & communication | 2024 |
| Kelson Consulting AS | Information & communication | 2007 |
| Kenvio AS | Financial services | 2013 |
| Kervel AS | Real estate | 2014 |
| Kevo Holding AS | | 2026 |
| KFL Solutions AS | Administrative & support | 2019 |
| Kfri Holding AS | | 2024 |
| KG 7 Eiendom AS | Real estate | 2021 |
| KGG Eiendom AS | | 2024 |
| KHJ Holding AS | | 2019 |
| Kiby AS | Professional & scientific | 2009 |
| Kikuthytta Cafe Og Selskapslokaler AS | Hospitality | 2016 |
| Kilebygda Montessoriskole SA | Education | 2009 |
| Kilebygda Service AS | Construction | 2015 |
| Kink With Class AS | Wholesale & retail | 2023 |
| Kio Service AS | Real estate | 2021 |
| Kiro Holding AS | Real estate | 2005 |
| Kirsebærlund Holding AS | | 2020 |
| Kise Holding AS | | 2025 |
| Kiste Eiendom AS | Construction | 2017 |
| Kjeldberg Drift AS | Hospitality | 2009 |
| Kjeldby Invest AS | | 2026 |
| Kjell Arne Løvli AS | Agriculture & fishing | 2006 |
| Kjell M Håkonsen AS | Health & social care | 2017 |
| Kjellemyr Eiendom AS | Real estate | 2011 |
| Kjellemyr Elektro AS | Construction | 2021 |
| Kjellemyr Industrier AS | Construction | 2021 |
| Kjelleveien 21 AS | Real estate | 2010 |
| Kjeps AS | Professional & scientific | 2013 |
| Kjær Plate Og Serviceverksted AS | Manufacturing | 1997 |
| Kjølnes Eiendom AS | Real estate | 2007 |
| Kjørbekk Auto AS | Wholesale & retail | 2016 |
| Kjørbekk Bolig AS | Real estate | 2019 |
| Kjørbekk Eiendom AS | Real estate | 1999 |
| Kjørbekk Invest AS | Real estate | 1991 |
| Kjørbekk Kiosk AS | Wholesale & retail | 2015 |
| Kjørbekkdalen 12 C AS | Construction | 2018 |
| Kjørbekkdalen 13 AS | Real estate | 2011 |
| Kjørbekkdalen 1B AS | Real estate | 2020 |
| Kjørbekkvegen 46 AS | Real estate | 2022 |
| Kjørbekkveien Eiendom AS | Real estate | 2009 |
| KK Gruppen AS | | 2019 |
| KK Service AS | Construction | 2013 |
| Klangwerk AS | Other services | 2025 |
| Klarpc Da | Wholesale & retail | 2025 |
| Klassiske Kunstkolleksjoner Da | Wholesale & retail | 1994 |
| Kledo AS | Wholesale & retail | 2021 |
| Kleiv Maskin AS | Manufacturing | 2008 |
| Kleivgrend AS | | 2011 |
| KLF Holding AS | Construction | 2014 |
| Klikk Regnskap AS | Professional & scientific | 2013 |
| Klinikk Skien AS | Health & social care | 2018 |
| Klinikk-Soleo AS | Health & social care | 2007 |
| Klippen Frisør Da | Other services | 1992 |
| Klocker Holding AS | | 2020 |
| Klokere Invest AS | Real estate | 2020 |
| Klondike Holding AS | | 2024 |
| Klosterfoss AS | Real estate | 2019 |
| Klosterfoss Smykkeverksted AS | Wholesale & retail | 1994 |
| Klosterfoss Utvikling AS | Real estate | 2007 |
| Klosterhagen Invest AS | | 2022 |
| Klosterhagen Legesenter AS | Health & social care | 2024 |
| Klosterhagen Legesenter Da | Health & social care | 2000 |
| Klosterskogen Eiendom AS | Real estate | 2012 |
| Klosterskogen Travbane AS | Arts & recreation | 1919 |
| Klosterstua AS | Hospitality | 1996 |
| Klosterøya Vest AS | Real estate | 2011 |