| Chesterfield Hotel AS | Hospitality | 2021 |
| Cheveux AS | Wholesale & retail | 2019 |
| Chez Marie AS | Other services | 2021 |
| Chi Salongen AS | Other services | 2013 |
| Chic Clinic AS | Other services | 2017 |
| Chic Puffin AS | Wholesale & retail | 2023 |
| Chick Chirp AS | Information & communication | 2025 |
| Chikara AS | Health & social care | 2015 |
| Chile-Nor Import Ans | Wholesale & retail | 2001 |
| Chill Charlie AS | Hospitality | 2024 |
| Chilli Frisører AS | Other services | 2014 |
| Chilli Invest AS | Real estate | 2003 |
| Chincha Consulting AS | Professional & scientific | 2020 |
| Chircu Trygg Bygg AS | Construction | 2026 |
| Chiron AS | Professional & scientific | 2019 |
| Chiron Oil Well Technologies AS | Manufacturing | 2001 |
| Chiron Pharmasynth AS | Manufacturing | 2001 |
| Choconation AS | | 2025 |
| Chop Chop Easyfood AS | Hospitality | 2024 |
| Chop Sticks AS | Hospitality | 2024 |
| Chop Sticks Holding AS | Hospitality | 2024 |
| Chop Sticks Horizont AS | Hospitality | 2024 |
| Chop Sticks Restaurant AS | Hospitality | 2024 |
| Chop Sticks Sirkus AS | Hospitality | 2024 |
| Chop Sticks Solsiden AS | Hospitality | 2015 |
| CHR Sørensen AS | Real estate | 1962 |
| Christian Schumann | Construction | 2012 |
| Christiania Taxi Trondheim AS | Transport & logistics | 2016 |
| Christin Hoff Band Ans | Arts & recreation | 1999 |
| Christine Marie Underland AS | | 2007 |
| Christophersen Ur & Gull AS | Wholesale & retail | 2012 |
| Chrom Eiendom AS | Real estate | 2008 |
| Chrom Invest AS | | 2021 |
| CHW AS | Professional & scientific | 2005 |
| Chymir AS | Information & communication | 2023 |
| Ciana AS | Other services | 2022 |
| Cicada Norge AS | Wholesale & retail | 2010 |
| Cicada Tattoo AS | Other services | 2025 |
| Cicero Dental AS | Manufacturing | 2023 |
| Cicerone Holding AS | Other services | 2005 |
| Cicu Holding AS | | 2026 |
| Cie Klein AS | Financial services | 2005 |
| Ciftja Technologies AS | Professional & scientific | 2019 |
| Cillco AS | Information & communication | 2022 |
| Cillco Consulting AS | Information & communication | 2022 |
| Cillco Technology AS | Information & communication | 2022 |
| Cimon Medical AS | Manufacturing | 2019 |
| Cinclus Eiendom Bodø AS | Real estate | 2012 |
| Cinclus Eiendom Haugesund AS | Real estate | 2008 |
| Cinclus Eiendom Kristiansund AS | Real estate | 2012 |
| Cinclus Eiendom Nord AS | Real estate | 2004 |
| Cinexus AS | Arts & recreation | 2025 |
| Circles and Crosses AS | Financial services | 2014 |
| Circulariaq AS | Water & waste | 2022 |
| Circulariaq Eiendom AS | Real estate | 2022 |
| Cirka Teater AS | Arts & recreation | 2001 |
| Cirsium AS | | 2025 |
| Ciss Invest AS | | 2023 |
| Cisterne AS | | 1992 |
| Citero AS | Administrative & support | 2016 |
| City Living AS | Hospitality | 2005 |
| City Living Sentrum AS | Hospitality | 2018 |
| City Market Central AS | Wholesale & retail | 2026 |
| City Taxi AS | Transport & logistics | 2018 |
| Cjahren 2 AS | | 2026 |
| Cjahren AS | | 2025 |
| CJS Holding AS | | 2022 |
| CK Consult AS | Administrative & support | 2021 |
| CK Frisør AS | Other services | 2013 |
| CKD Holding AS | | 2024 |
| CKR Holding AS | | 2021 |
| Claritychain AS | Information & communication | 2025 |
| Claus Holding AS | Financial services | 2004 |
| Clausen & Keller AS | Wholesale & retail | 1970 |
| Clausen AS | Real estate | 2022 |
| Clausen Drift AS | Real estate | 2026 |
| Clawd Industries AS | Information & communication | 2026 |
| Clean Sea Solutions AS | Professional & scientific | 2017 |
| Clean Tunnel Air International AS | Construction | 2006 |
| CLEAN4DREAM AS | Administrative & support | 2023 |
| Cleanflow AS | Information & communication | 2025 |
| Cleantec AS | Administrative & support | 2019 |
| Clear Insight AS | Professional & scientific | 2026 |
| Clematis AS | Real estate | 2016 |
| Click & Go AS | Administrative & support | 2023 |
| Clinique Cicerone Ans | Other services | 1984 |
| Clinique Cicerone AS | Other services | 2006 |
| Close AS | Education | 2016 |
| Clueless AS | | 2025 |
| Clutch Holding AS | | 2024 |
| CLV Eiendom AS | Real estate | 2022 |
| CM Aqua AS | Agriculture & fishing | 2021 |
| CM Estate AS | Real estate | 2022 |
| CM Properties AS | Real estate | 2016 |
| CMM Invest Holding AS | Real estate | 2021 |
| CNX AS | Wholesale & retail | 2012 |
| CNX Eiendom AS | Real estate | 2021 |
| CNX Utvikling AS | Professional & scientific | 2025 |
| Co Link AS | Transport & logistics | 2009 |
| CO2 Technology AS | Professional & scientific | 2015 |