| Crave Nutrition AS | Manufacturing | 2026 |
| Crayonano AS | Professional & scientific | 2012 |
| Crazy Coyote Events Ans | Arts & recreation | 2006 |
| Creacom Holding AS | Wholesale & retail | 2011 |
| Crear AS | Real estate | 2011 |
| Crear Eiendom AS | Real estate | 2017 |
| Crear Regnskap AS | Professional & scientific | 2009 |
| Creare Invest AS | Real estate | 2026 |
| Createx AS | Professional & scientific | 2026 |
| Creative Collective Trondheim AS | Arts & recreation | 2026 |
| Creator AS | Education | 2005 |
| Creatorsjourney AS | | 2020 |
| Creditreform Holding AS | Professional & scientific | 1919 |
| Credoveita 2 AS | Real estate | 2015 |
| Creo Digital AS | Information & communication | 2023 |
| Creor AS | Wholesale & retail | 2016 |
| Creos Eiendom AS | Real estate | 2020 |
| Crescimento AS | | 2021 |
| Crestpoint Invest AS | | 2025 |
| Creto Næringsmegling AS | Real estate | 1997 |
| Creto Regnskap AS | Professional & scientific | 2005 |
| Creto-Gruppen AS | Professional & scientific | 1992 |
| Crimson AS | Information & communication | 2016 |
| Crispin Glover Record Shop AS | Wholesale & retail | 2017 |
| Crispin Glover Records AS | Information & communication | 2017 |
| Crispy Fried Chicken AS | Hospitality | 2017 |
| Crosten Projects AS | Real estate | 2005 |
| Crowdreflex AS | Information & communication | 2016 |
| CRS Capital AS | | 2026 |
| Cruise Master AS | Administrative & support | 1999 |
| Cruise Trondheim AS | Hospitality | 1995 |
| Crystal Service AS | Administrative & support | 2013 |
| CSH Holding AS | | 2021 |
| Csjm AS | Professional & scientific | 2025 |
| Csveen AS | Professional & scientific | 2022 |
| Csveen Holding AS | Professional & scientific | 2022 |
| CT Aktiv AS | Health & social care | 2021 |
| Cti AS | Administrative & support | 1990 |
| Ctjo AS | Financial services | 2017 |
| Ctjo Eiendom AS | | 2018 |
| CTM Eiendom AS | Real estate | 1992 |
| CTM Holding AS | Real estate | 2021 |
| Ctoy AS | | 2021 |
| Culinarisservice AS | Education | 2025 |
| Culinova AS | Manufacturing | 2021 |
| Cura AS | Transport & logistics | 2025 |
| Cura Di Automobile AS | Other services | 2019 |
| Curatorklinikken Da | Health & social care | 2013 |
| Cut 4 U Frisør AS | Other services | 2001 |
| Cyber Invest AS | Information & communication | 2005 |
| Cyberize AS | Professional & scientific | 2025 |
| Cybernetica AS | Professional & scientific | 2024 |
| Cybernetica Holding AS | Professional & scientific | 2024 |
| Cybernetica Technology AS | Professional & scientific | 2024 |
| Cybersea Holding AS | | 2019 |
| Cybr Invest AS | Professional & scientific | 2021 |
| Cylmo AS | Other services | 1999 |
| Cypress Software AS | Information & communication | 1992 |
| Czechoslonor AS | Professional & scientific | 1990 |
| CZK AS | | 2024 |
| Casa Blanca A/S | Real estate | 1988 |
| Cálcibus Investment AS | Financial services | 2016 |
| D. Eriksen Holding AS | Real estate | 2017 |
| D818 Eiendom & Invest AS | Real estate | 2019 |
| Daaland Eiendomsutvikling AS | Manufacturing | 2006 |
| Daaland Invest AS | Manufacturing | 2005 |
| Dabrula Holding AS | Construction | 2023 |
| Dafor AS | Agriculture & fishing | 2020 |
| Dag Hoel Filmproduksjon AS | Information & communication | 2003 |
| Dag Werner Solberg AS | Health & social care | 2012 |
| Dagestad Invest AS | Financial services | 2014 |
| Dagfinn AS | Financial services | 2009 |
| Dahe Invest AS | Real estate | 2019 |
| Dahl Andersen - Testledelse Og Rådgiving AS | Professional & scientific | 2019 |
| Dahl Dagligvare AS | Wholesale & retail | 2023 |
| Dahle Bil AS | Other services | 2017 |
| Dahle Capital AS | | 2026 |
| Dahle Verdi AS | | 2026 |
| Dahlhaug Forsikringsformidling AS | | 2024 |
| Dahlhaug Invest AS | Information & communication | 2005 |
| Dahlia Invest AS | Real estate | 2024 |
| Dalai Solutions AS | Information & communication | 2024 |
| Dalgård Bakeri AS | Hospitality | 2019 |
| Dalgård Bolig AS | Real estate | 2015 |
| Dalgård Legesenter Da | Health & social care | 2009 |
| Dalgård Utvikling AS | Real estate | 2013 |
| Dalheim Consult AS | Professional & scientific | 2016 |
| Daling Rams Consulting AS | Professional & scientific | 2009 |
| Dall Frøseth AS | Information & communication | 2017 |
| Dalsan AS | | 2024 |
| Dalsaunevegen 5 AS | Real estate | 2024 |
| Dalsplass Holding AS | | 2024 |
| Dampoteket AS | Wholesale & retail | 2015 |
| Damsgård Brygge AS | Real estate | 2016 |
| Danas Holding AS | | 2015 |
| Dance Holding AS | | 2017 |
| Danebo Utvikling AS | Real estate | 2008 |
| Danelakis Holding AS | | 2023 |
| Daniel Klein AS | Wholesale & retail | 2023 |
| Daniel På Hjørnet AS | Hospitality | 1995 |