| Klæbuveien 196 B Ans | Real estate | 1985 |
| Klæbuveien 196B AS | Real estate | 2004 |
| Klæbuveien 201 AS | Households | 1956 |
| Klæbuveien 205 AS | Real estate | 2019 |
| Klæbuveien Utvikling AS | Real estate | 2016 |
| KM Bolig AS | Real estate | 2017 |
| KM Engineering AS | Professional & scientific | 2017 |
| KMF Kapital AS | | 2026 |
| KML Næringsprosjekter AS | Real estate | 2013 |
| KMR1 Holding AS | | 2025 |
| Kmte AS | | 2013 |
| KN Invest AS | Real estate | 2006 |
| Knarr L.L.C. Nuf | Administrative & support | 2021 |
| Knausen DS AS | | 2025 |
| Kneip AS | Hospitality | 2023 |
| Knot AS | Wholesale & retail | 2024 |
| Know How Holding AS | | 2016 |
| Kntrktr AS | | 2024 |
| Knuseverk Trading International AS | Manufacturing | 2013 |
| Knut Lossius Taxi AS | Transport & logistics | 2017 |
| Knut P Holding AS | | 2023 |
| Knutepunktet AS | Real estate | 2026 |
| Knutshaug VVS AS | Construction | 2017 |
| Knuva Bygg AS | Construction | 2022 |
| Knæpp AS | Information & communication | 2018 |
| Ko Data Consulting AS | Information & communication | 2021 |
| Kobbe AS | Wholesale & retail | 2020 |
| Kobbes Gate 10 AS | Real estate | 2008 |
| Kobtas AS | Construction | 2019 |
| Kobygg AS | Construction | 2021 |
| Kodeworks AS | Information & communication | 2018 |
| Kodeworks Eiendom AS | Real estate | 2018 |
| Kodeworks Trondheim AS | Information & communication | 2018 |
| Koffernor AS | Professional & scientific | 2023 |
| Kognai AS | Information & communication | 2025 |
| Koie Trondheim AS | Hospitality | 2021 |
| Kokkeriet AS | Hospitality | 2016 |
| Kokko Arkitektur Da | Professional & scientific | 2007 |
| Kokko Kakao AS | Wholesale & retail | 2025 |
| Kokong Økonomi AS | Professional & scientific | 2014 |
| Kokosh AS | Real estate | 2006 |
| Kolbjørn Johnsen Eiendom AS | Real estate | 1968 |
| Kolbyone AS | | 2021 |
| Kolibrihuset AS | Information & communication | 2018 |
| Kollitaxi AS | Transport & logistics | 2002 |
| Kolstad Arena AS | Real estate | 2015 |
| Kolvik Invest AS | Professional & scientific | 2008 |
| Kometen AS | Real estate | 2006 |
| Kommunearkivinstitusjonenes Digitale Ressurssenter SA | Arts & recreation | 2010 |
| Kompass Design AS | Professional & scientific | 2000 |
| Kompetansepartner Trondheim AS | Professional & scientific | 2013 |
| Kompetansesenter Og Bedriftshjelp AS | Education | 2017 |
| Kompis Byåsen AS | Hospitality | 2016 |
| Kompis Foodtruck AS | Hospitality | 2021 |
| Kompis Lade AS | Hospitality | 2016 |
| Kompis Norge AS | Hospitality | 2016 |
| Kompis Produksjonskjøkken AS | Hospitality | 2021 |
| Kompis Singsaker AS | Hospitality | 2022 |
| Kompis Sorgenfri AS | Hospitality | 2020 |
| Komplett Kost Ans | Education | 2003 |
| Komplett Montert AS | Construction | 2026 |
| Konekon AS | Financial services | 2005 |
| Konfluent AS | Information & communication | 2021 |
| Kong Inge AS | Professional & scientific | 2017 |
| Kongens Gate 32 AS | Real estate | 2023 |
| Kongens Gate 44 AS | Real estate | 2023 |
| Kongens Gate 44 Hjemmel AS | Real estate | 2009 |
| Kongens Gate 87 AS | Real estate | 2019 |
| Kongens GT. 21 AS | Real estate | 2012 |
| Kongensgata 60 AS | Real estate | 2015 |
| Kongletoppen Familiebarnehage AS | Education | 2015 |
| Konik AS | Information & communication | 2011 |
| Konos AS | Professional & scientific | 2016 |
| Konos Eiendom AS | Real estate | 2012 |
| Konstad Hansen Holding AS | | 2020 |
| Konstellasjonen AS | Arts & recreation | 2012 |
| Konsul Knudtzons Gate 1 AS | Real estate | 2023 |
| Konsulen AS | Real estate | 2002 |
| Konsulenten Reidar Nygård AS | Information & communication | 2013 |
| Konsultenergy AS | Administrative & support | 2026 |
| Kontra Shop AS | Hospitality | 2025 |
| Kontrast Kantine AS | Hospitality | 2017 |
| Kontrex AS | Administrative & support | 2013 |
| Kontur AS | Professional & scientific | 2001 |
| Koppang Næringspark AS | Real estate | 2023 |
| Kopperen AS | | 2025 |
| Koren Optikk Trondheim AS | Wholesale & retail | 2011 |
| Korkon AS | | 2020 |
| Korkon Holding AS | Financial services | 2016 |
| Korssjøen Invest AS | Financial services | 2008 |
| Korsvika Terrasse AS | Real estate | 2017 |
| Kortfri Norge AS | Information & communication | 2017 |
| Korund AS | Information & communication | 2017 |
| Kose-Krok Da | Wholesale & retail | 2025 |
| Koselige Hus AS | Construction | 2017 |
| Koteng Bolig AS | Real estate | 2005 |
| Koteng Drift AS | Real estate | 2018 |
| Koteng Eiendom AS | Administrative & support | 1999 |
| Koteng Holding AS | Real estate | 2005 |
| Koteng Hylleselskap 2 AS | Real estate | 2016 |