| KK Renhold AS | Lillehammer | 2023 |
| Kk-Renhold Da | Fagerstrand | 2009 |
| KKM V/B Carlsson Norsk Avdeling Av Utenlandsk Foretak Nuf | Slemmestad | 1999 |
| KL Varme AS | Kongsvinger | 2019 |
| Klaff AS | Mo I Rana | 2012 |
| Klaff Holding AS | Mo I Rana | 2017 |
| Klakegg AS | Førde | 2026 |
| Klar Hytte & Vaktmestertjenester AS | Nesbyen | 2015 |
| Klar Rekruttering AS | Skedsmokorset | 2016 |
| Klar Renhold AS | Oslo | 2025 |
| Klar Til Bruk AS | Lillestrøm | 2024 |
| Klare Inkasso AS | Bodø | 2011 |
| Klaria AS | Greåker | 2025 |
| Klart AS | Tromsø | 2020 |
| Klatreeventyr AS | Oslo | 2018 |
| Klaudor Grzegorz Rogowski Nuf | Langevåg | 2009 |
| Klaus Schuwerk Gesellschaft Von Architekten MBH | De-10999 Berlin | 2011 |
| Klausen Service AS | Sandnessjøen | 2025 |
| Klavenes Industriservice AS | Holmestrand | 1984 |
| Klaveness Marine Finance AS | Oslo | 2011 |
| Klaveness Marine Holding AS | Oslo | 2011 |
| KLB I Dalarna AB | Larvik | 2015 |
| Kleemann Hellas A.E. | Gr-6100 Kilkis | 2024 |
| Kleenerr AS | Oslo | 2022 |
| Kleihues + Kleihues Gesellschaft Von Architekten MBH | De-10587 Berlin | 2011 |
| Kleivstad AS | Oslo | 2026 |
| Klepp Gokartutleie AS | Kleppe | 2026 |
| Klepp Spesialtransport Ans | Kleppe | 1997 |
| Kletor AS | Alta | 2011 |
| Kletor Sverige AB Nuf | Se-211 38 Malmø | 2024 |
| Klev Bygg Og Vedlikehold AS | Mandal | 2018 |
| Kleveland's Utemiljø AS | Trondheim | 2006 |
| Kleven Anleggsteknikk AS | Alta | 2023 |
| Kleven Maritime Contracting AS | Ulsteinvik | 2008 |
| Klikko Aps | Dk-2500 Valby | 2019 |
| Klima & Miljøteknikk AS | Vennesla | 2019 |
| Klimaeksperten AS | Oslo | 2025 |
| Klingen Daams Holding AS | Oslo | 2005 |
| Klingen Eiendom AS | Spillum | 2013 |
| Klingsheim Hogst & Hage AS | Sandnes | 2021 |
| Klinikken På Travparken AS | Knarrevik | 1999 |
| Klinito Holding AS | Reistad | 2025 |
| Kloke Hoder AS | Stavanger | 2018 |
| Klokkerud Krets Fiberlag SA | Ørje | 2022 |
| Klompen AS | Hundvin | 2018 |
| Klopp Verksted Holding AS | Ramnes | 2017 |
| Klubb Sponsor AS | Stavanger | 2004 |
| Klubblisten Da | Kleppestø | 2021 |
| Klubbneset Drift Og Vedlikehold AS | Kvenvær | 2025 |
| Klype Ved Og Hytteservice AS | Nesbyen | 2023 |
| Klyra Norge AS | Flatåsen | 2026 |
| Klyra Trondheim AS | Flatåsen | 2025 |
| Klyva AS | Rong | 2008 |
| Kløfta Vedlikehold AS | Kløfta | 2013 |
| Kløkt Selection AS | Oslo | 2021 |
| Kløver Utleie Da | Skatval | 2011 |
| KM Agency AS | Skjetten | 2024 |
| KM New Energy AS | Oslo | 2020 |
| KM Regnskap AS | Kopperå | 2007 |
| KM Vestland AS | Breistein | 2015 |
| KMG Byggservice AS | Strømmen | 2016 |
| KMG Maskin AS | Strømmen | 2004 |
| KML Holding AS | Rådal | 2005 |
| Kmphoto-Expeditions AS | Longyearbyen | 2016 |
| Kmrs Reinhold AS | Hareid | 2025 |
| KMS Eiendom & Drift - Kristoffervalen Brygge AS | Vannvåg | 2024 |
| Kmu AS | Røn | 2018 |
| KN Kompetanse AS | Nesbyen | 2018 |
| KN Reinhald AS | Stryn | 2021 |
| KN Service AS | Stavang | 2021 |
| Knaben Via Ferrata AS | Kvinlog | 2019 |
| Knapper Snø & Skogsdrift AS | Knapper | 2014 |
| Knapstad Renhold Service AS | Knapstad | 2017 |
| Knar Utleie Ans | Finnsnes | 2000 |
| Knarr L.L.C. Nuf | Trondheim | 2021 |
| Knarrlagsund Holding AS | Ansnes | 2005 |
| Knas Holding AS | Oslo | 2005 |
| KNAUS1 Holding AS | Vågå | 2015 |
| KND AS | Selbu | 2019 |
| Knead AS | Oslo | 2020 |
| Knif Fundraising AS | Oslo | 2021 |
| Knight Oil Ltd | Angus Ab11 6Ld Scotland | 2019 |
| KNK Tour AS | Ås | 2017 |
| KNM Hydraulikk AS | Sola | 2008 |
| KNM Hydraulikk Holding AS | Sola | 2023 |
| Knoll & Tott Vaktmestertjenester AS | Sannidal | 2020 |
| Knoll Exploration Inc | Co 81137 | 2011 |
| Knowledgebase AS | Oslo | 2019 |
| Knownid AB | Se-114 28 Stockholm | 2025 |
| Knust Event AS | Oslo | 2023 |
| Knut Aalton AS | Nesbyen | 2023 |
| Knut Bergen AS | Longyearbyen | 2019 |
| Knut Jønholt AS | Kviteseid | 1990 |
| Knut Knutsen & Co AS | Sellebakk | 1988 |
| Knut Raa AS | Lærdal | 1990 |
| Knut-Eilif Bakkevold AS | Lakselv | 2018 |
| Knutsen Drift AS | Alta | 2022 |
| Knutsen Oas Crewing AS | Haugesund | 2010 |
| Knutsen Oas Crewing Eastern Europe AS | Haugesund | 2023 |
| Knutsen Oas ML AS | Haugesund | 2018 |