| Corniche AS | Real estate | 2023 |
| Corniche Innredning AS | Wholesale & retail | 1996 |
| Corno Kommunikasjon AS | Professional & scientific | 2022 |
| Cornucopia AS | Professional & scientific | 2010 |
| Cornucopia Holding AS | Real estate | 2021 |
| Coro Holding AS | | 2025 |
| Corolla Holding AS | | 2024 |
| Corondum AS | | 2017 |
| Coronet Norge AS | Transport & logistics | 1969 |
| Corp Capital AS | | 2012 |
| Corpcann AS | Professional & scientific | 2017 |
| Corpeople AS | | 2001 |
| Corper AS | Professional & scientific | 2025 |
| Corporate Charity Management AS | Administrative & support | 2021 |
| Corporate Communications AS | Professional & scientific | 2011 |
| Corporate Communications Partners AS | | 2026 |
| Corporate Eiendom AS | | 2024 |
| Corporate Good AS | Professional & scientific | 2015 |
| Corporate Lyd Og Lys Ans | Arts & recreation | 2004 |
| Corporate Novator AS | Professional & scientific | 2005 |
| Corporate Partners AS | Administrative & support | 2015 |
| Corporate Spring AS | Professional & scientific | 2012 |
| Corporis AS | Education | 2018 |
| Corral's AS | Wholesale & retail | 2022 |
| Corrals Holding AS | Hospitality | 2023 |
| Corrals Import & Innkjøp AS | Wholesale & retail | 2025 |
| Corrals Tacos AS | Hospitality | 2024 |
| Corrals Økern AS | Hospitality | 2024 |
| Correlate AS | Information & communication | 2015 |
| Corrientes AS | Health & social care | 2017 |
| Corroventa Avfuktning AS | Wholesale & retail | 2011 |
| Corsa Auto AS | Wholesale & retail | 2025 |
| Corsi AS | Hospitality | 2020 |
| Cort Adelers Gate 27 AS | Real estate | 2024 |
| Cort Adelers Gate 30 AS | Real estate | 2019 |
| Cort Adelers Gate Centre AS | Real estate | 2012 |
| Cort Adlersgt 20 Næring AS | Real estate | 2006 |
| Cortana AS | | 2017 |
| Cortana Invest AS | | 2025 |
| Cortex Invest AS | Financial services | 2020 |
| Cortex RS Holding AS | | 2025 |
| Cortezzi AS | Wholesale & retail | 1995 |
| Corticalis AS | Professional & scientific | 2006 |
| Coruna AS | Real estate | 2005 |
| Corvara Industri- Och Skadeservice AB | Administrative & support | 2013 |
| Corvenia AS | Information & communication | 2025 |
| Corvita AS | Health & social care | 2018 |
| Corvita Care AS | Health & social care | 2022 |
| Corvita Eiendom AS | Real estate | 2019 |
| Corvita Kompetanse AS | Health & social care | 2020 |
| Corvita Tonsåsen AS | Real estate | 2023 |
| Corvue AS | Information & communication | 2024 |
| Corvus Accounting AS | Professional & scientific | 1996 |
| Corvus Consulting AS | Administrative & support | 1998 |
| Cos Cob AS | Real estate | 2005 |
| Cos Med AS | Other services | 1990 |
| Cosac AS | Information & communication | 2018 |
| Cosco Shipping Lines Nordic A/S Nuf | Transport & logistics | 2003 |
| Coseb AS | | 2019 |
| Cosentino Scandinavia AB | Wholesale & retail | 2009 |
| Cosimo AS | | 2005 |
| Cosinus AS | | 1996 |
| Cosinus Da | | 1993 |
| Cosmederm Methods AS | Wholesale & retail | 1996 |
| Cosmedic AS | Wholesale & retail | 2002 |
| Cosmedica AS | Wholesale & retail | 2012 |
| Cosmic AS | Administrative & support | 1997 |
| Cosmo AS | Professional & scientific | 2013 |
| Cosmo Clinic AS | Health & social care | 2016 |
| Cosmo Produksjoner Da | Arts & recreation | 2021 |
| Cosmo-Tex AS | Wholesale & retail | 1990 |
| Cosmos Capital AS | | 2025 |
| Cosmos Music Norway AS | Information & communication | 1999 |
| Cosmotech AS | Information & communication | 2021 |
| Cospaia AS | | 2021 |
| Cossmo AS | Real estate | 2019 |
| Cost Partner Group AS | Professional & scientific | 2010 |
| Cost Partner Norge AS | Professional & scientific | 2017 |
| Cost Reduction Management AS | Professional & scientific | 2014 |
| Costa Del Sol Eiendom AS | | 2013 |
| Costa Plenty AS | Real estate | 2000 |
| Costadels AS | Hospitality | 2024 |
| Coste De Mar AS | Hospitality | 2019 |
| Costello Consulting AS | Information & communication | 2022 |
| Costello Group AS | Information & communication | 2022 |
| Costtracker AS | Professional & scientific | 2016 |
| Cotera AS | Wholesale & retail | 2025 |
| Cotopaxi AS | Professional & scientific | 2020 |
| Cottesloe AS | Information & communication | 2018 |
| Cotton & Co AS | Wholesale & retail | 2019 |
| Cotè Bretagne AS | Wholesale & retail | 2011 |
| Couch AS | Hospitality | 2018 |
| Couleur AS | Professional & scientific | 2020 |
| Counter Culture Liquids AS | Wholesale & retail | 2016 |
| Coup De Coeur Invest AS | Financial services | 2011 |
| Coupler Holding AS | Professional & scientific | 2020 |
| Coupler Oslo AS | Information & communication | 2020 |
| Cour Rent Services AS | Transport & logistics | 2025 |
| Court of Owls AS | Arts & recreation | 2026 |
| Cousi Holding AS | Financial services | 2010 |