| Cascade Eiendom Ans | Real estate | 1993 |
| Cascade Scandinavia Hydraulik AB | Manufacturing | 1995 |
| Casch Norway | | 1997 |
| Case AS | | 2026 |
| Caseb AS | Wholesale & retail | 1983 |
| Caseb Holding AS | Professional & scientific | 2005 |
| Casen AS | Real estate | 2012 |
| Cases AS | Arts & recreation | 2026 |
| Casett Invest AS | | 2021 |
| Casf Invest AS | | 2021 |
| Casfila Invest AS | Financial services | 2006 |
| Cash Back Norge AS | Administrative & support | 1991 |
| Cash Flow Zone Invest AS | Financial services | 2021 |
| Cash Invest AS | Financial services | 2005 |
| Cash Is Kindz AS | Real estate | 2021 |
| Cashper AS | Information & communication | 2026 |
| Casi Eiendom AS | Hospitality | 2022 |
| Casico AS | Professional & scientific | 2021 |
| Casiha AS | | 2025 |
| Casingo AS | Arts & recreation | 1986 |
| Casis AS | Financial services | 2010 |
| Casjo AS | Real estate | 2005 |
| Cask AS | Wholesale & retail | 2000 |
| Cask Owners AS | Wholesale & retail | 2008 |
| Casnor Holding AS | Financial services | 2018 |
| Caspar Storms Vei 14 AS | Real estate | 2006 |
| Caspar Storms Vei 17 AS | Real estate | 2005 |
| Caspar Storms Vei 8/19 AS | Real estate | 2024 |
| Caspar Stormsvei Fremleie AS | Real estate | 2018 |
| Caspara Items AS | Wholesale & retail | 2023 |
| Caspari Aps Nuf | Wholesale & retail | 1995 |
| Caspeco Norge AS | Information & communication | 2018 |
| Casper the Friendly AS | | 2025 |
| Caspian Holding AS | | 2020 |
| Caspian Invest AS | Financial services | 2015 |
| Cass Paus Holding AS | | 2021 |
| Cassandra Modellbureau Ans | | 1988 |
| Cassette Publishing AS | Information & communication | 2019 |
| Cassini AS | Professional & scientific | 2017 |
| Cassinis AS | Real estate | 2023 |
| Cassinis Invest AS | Professional & scientific | 2019 |
| Casso AS | Hospitality | 2019 |
| Cast AS | Arts & recreation | 2021 |
| Castegren Invest AS | | 2026 |
| Castel AS | Real estate | 2017 |
| Castelar Prosjekt 22 AS | Real estate | 2017 |
| Castelo 21 Invest AS | | 2025 |
| Castelo AS | Real estate | 2003 |
| Caster Norge AS | Transport & logistics | 2022 |
| Castille Atlantic Inc. Nuf | Administrative & support | 2025 |
| Castillo Hovde E-Learning AS | Education | 2018 |
| Castl AS | | 2025 |
| Castle Film AS | Arts & recreation | 1974 |
| Castle Invest AS | | 2024 |
| Castle Stone AS | Education | 1994 |
| Castle Stones Norge AS | Wholesale & retail | 2019 |
| Castles Group AS | Hospitality | 2025 |
| Castor - August AS | Professional & scientific | 2005 |
| Castor August Eiendom AS | Real estate | 2017 |
| Castor August Utvikling AS | Real estate | 2017 |
| Castor Finans Da | Administrative & support | 2002 |
| Castor Gruppen AS | Real estate | 1962 |
| Castor Invest AS | Financial services | 1995 |
| Castor Mekaniske AS | Manufacturing | 2012 |
| Castorp AS | | 2020 |
| Castra AS | Information & communication | 1994 |
| Castras AS | Information & communication | 2015 |
| Castrol Norway AS | Wholesale & retail | 1970 |
| Casus Advokatfirma AS | Professional & scientific | 2020 |
| Casweb AS | Information & communication | 2023 |
| Cat & Care AS | Agriculture & fishing | 2021 |
| Cat 7 Eiendomsinvest AS | Real estate | 2007 |
| Cat Catering AS | Hospitality | 2019 |
| Cat Tech (Europe) Ltd | Administrative & support | 2005 |
| CAT66 Holding AS | | 2024 |
| Catalina Holding AS | Real estate | 2005 |
| Catalpa Holding AS | | 2015 |
| Catalyst Invest AS | Real estate | 2018 |
| Catalystone Solutions AS | Information & communication | 2015 |
| Catalystone Solutions Holding AS | Information & communication | 2017 |
| Catalysts Consulting AS | Professional & scientific | 2023 |
| Catalysts Technologies AS | Professional & scientific | 2014 |
| Catana AS | Real estate | 1998 |
| Catasteri AS | Professional & scientific | 2015 |
| Catastrophic Games AS | Information & communication | 2016 |
| Catch 44 AS | | 2018 |
| Catch Rekruttering AS | Administrative & support | 2022 |
| Catchwise AS | Information & communication | 2023 |
| Catena AS | Wholesale & retail | 2005 |
| Catenda AS | Professional & scientific | 2009 |
| Catering & Crew AS | Hospitality | 2002 |
| Catering Oslo AS | Hospitality | 2014 |
| Cateringo AS | Information & communication | 2018 |
| Cathalyst AS | Professional & scientific | 2018 |
| Catharina Horn AS | Administrative & support | 1995 |
| Cathay Holding AS | Real estate | 1936 |
| Cathbycn AS | Information & communication | 2025 |
| Cathrine Amalie Bjørke AS | Health & social care | 2022 |
| Cathrine Bach AS | Information & communication | 2005 |
| Cathrine Decor AS | Professional & scientific | 2024 |