| J. Thorgård Holding AS | Construction | 2016 |
| Jan Vidar Wiseth AS | Wholesale & retail | 2017 |
| Jarle Negård Eiendom AS | Real estate | 2021 |
| JBD AS | Financial services | 2018 |
| Jepco AS | Professional & scientific | 2017 |
| Jets Interiør AS | Wholesale & retail | 2016 |
| Jetsa Holding AS | Wholesale & retail | 2016 |
| Jfu Holding AS | | 2019 |
| JHT Solutions AS | Information & communication | 2022 |
| Jim R Bruaset Holding AS | Real estate | 2017 |
| Jky Trondheim AS | Arts & recreation | 2026 |
| Jne Holding AS | Real estate | 2021 |
| Jo Storsten Service AS | Construction | 2012 |
| Johannessen AS | Construction | 2019 |
| Johannessen Og Hagen AS | Construction | 1996 |
| John Berg Holding AS | Financial services | 2005 |
| Jon Arne Langørgen AS | Construction | 2014 |
| Jonnes Blikk Og Eiendom AS | Construction | 2023 |
| Jos AS | Transport & logistics | 2015 |
| Jotra AS | Transport & logistics | 2018 |
| JS Produkter AS | | 2017 |
| Jub Holding AS | Financial services | 2017 |
| JVK Holding AS | Financial services | 2018 |
| K Consulting Nuf | Education | 2018 |
| K Stensrud AS | Information & communication | 2026 |
| K Stensrud Holding AS | | 2026 |
| K&S Beauty AS | Administrative & support | 2018 |
| K. Johannessen Holding AS | | 2018 |
| K.Sæther Holding AS | | 2023 |
| K2S Bygg Og Eiendom AS | Construction | 2014 |
| Kaadoya AS | Wholesale & retail | 2026 |
| Kadri Holding AS | | 2021 |
| Kaffesup AS | Hospitality | 2022 |
| Kakoto Eiendom AS | Real estate | 2004 |
| Kaliber Gym Trondheim AS | Arts & recreation | 2002 |
| Karlgård Eiendom AS | Wholesale & retail | 2014 |
| Karlgård Regnskap AS | Professional & scientific | 2022 |
| Karma Consulting AS | Health & social care | 2002 |
| Kartonage AS | Manufacturing | 2003 |
| Kartonage Eiendom AS | Real estate | 1925 |
| Kastis Bygg AS | Construction | 2026 |
| Katrinefoto AS | Professional & scientific | 2013 |
| Kattemskogen Barnehage AS | Education | 2006 |
| Kavest AS | | 2025 |
| Kene AS | Administrative & support | 2018 |
| KFJ Capital AS | | 2022 |
| KGP Invest AS | Real estate | 2013 |
| Kim Almås Holding AS | Construction | 2023 |
| Kim Frisør AS | Other services | 2020 |
| Kjell Knutsen AS | Administrative & support | 2020 |
| Kjem AS | Professional & scientific | 2011 |
| Kjørsvik Stenhuggeri AS | Manufacturing | 1997 |
| KKM Invest AS | Real estate | 2019 |
| Klausen Consulting AS | Professional & scientific | 2025 |
| Klipperiet Holding AS | Other services | 2005 |
| Klipperiet Stolpnes AS | Other services | 2003 |
| Klæbuveien 162 AS | Real estate | 2021 |
| KM Auto Heimdal AS | Other services | 2020 |
| KM Bygg Entreprenør AS | Construction | 2013 |
| Kneppe Vest AS | Real estate | 2021 |
| Kodama Binderi AS | Arts & recreation | 2008 |
| Kofoed AS | Professional & scientific | 2026 |
| Kolbjørn Holding AS | Real estate | 2019 |
| Kompis Heimdal AS | Hospitality | 2017 |
| Konfekten Produkter AS | Wholesale & retail | 2012 |
| Kongsvarden AS | Professional & scientific | 2004 |
| Kongsvegen Barnehage AS | Education | 2022 |
| KR Rådgivning AS | Professional & scientific | 2021 |
| Kran Og Transport Trondheim AS | Administrative & support | 2024 |
| Krida Ventures AS | | 2020 |
| Kripta AS | Hospitality | 2019 |
| Kriso Holding AS | | 2026 |
| KRR Holding AS | | 2022 |
| Krystian Bygg AS | Construction | 2021 |
| Krystian Byggkomponenter AS | Wholesale & retail | 2019 |
| Krystian Holding AS | Construction | 2019 |
| KSR Invest AS | Information & communication | 2017 |
| Kulinarium AS | Hospitality | 1998 |
| Kvams Minde AS | Real estate | 2025 |
| Kvannli AS | Information & communication | 2018 |
| Kvenildmyra 2 AS | Real estate | 2020 |
| Kvenildstrøa 51 AS | Real estate | 2017 |
| Kvenildstrøa 53 AS | Real estate | 2021 |
| Kvenildstrøa Eiendom AS | Construction | 2016 |
| Kvenildstrøa Veg AS | Wholesale & retail | 2021 |
| Kvenildtrøa Eiendom AS | Real estate | 2019 |
| Kvenildveien 15B AS | Real estate | 2026 |
| Kvernberg Holding AS | | 2019 |
| Kåre Sivertsen AS | Real estate | 1976 |
| Ladalen AS | Real estate | 2021 |
| Landbrukssalg.No AS | Wholesale & retail | 2023 |
| Langmo AS | Real estate | 2007 |
| Langørgen Agri AS | Agriculture & fishing | 2025 |
| Langørgen Holding AS | Other services | 2013 |
| Lars E Holding AS | Manufacturing | 2021 |
| Lars Høyem AS | Construction | 2020 |
| Lars Utseth AS | Education | 2018 |
| LBJ Fysioterapitjenester AS | Health & social care | 2022 |
| Leb Holding AS | Construction | 2016 |
| Leb Invest AS | Real estate | 2017 |