| C. Houge-Thiis Fysioterapi AS | Stavanger | 2007 |
| C.Muller AS | Trondheim | 2023 |
| C3 Kiropraktorklinikk AS | Sætre | 2014 |
| Ca Klikikken AS | Fana | 2023 |
| Ca Medispa AS | Brekkestø | 2015 |
| Cab AS | Rådal | 2014 |
| Caconym AS | Buvika | 2022 |
| Caligula Holding AS | Moss | 2012 |
| Calm AS | Lillesand | 2021 |
| Calma Tannklinikk AS | Harstad | 2019 |
| Calmio AS | Slependen | 2024 |
| Camilla Hovig Legetjenester AS | Fana | 2026 |
| Camilla Paus AS | Nesøya | 2005 |
| Camilla Rostrup Logoped AS | Oslo | 2023 |
| Camilla Sage AS | Florvåg | 2020 |
| Camilla Stadheim Hellum AS | Oslo | 2021 |
| Camillas Fotterapi AS | Lillehammer | 2014 |
| Camino Segoro Norge | Hafrsfjord | 2002 |
| Camp Livet AS | Mo I Rana | 2023 |
| Campus Familia AS | Bø I Telemark | 2013 |
| Campus Private Klinikk AS | Kristiansund N | 2022 |
| Cancer Consulting AS | Oslo | 2025 |
| Candeo AS | Ålgård | 2008 |
| Candtann AS | Tromsø | 2018 |
| Caninus AS | Drammen | 2023 |
| Capable Tech AS | Halden | 2024 |
| Capasand AS | Horten | 2007 |
| Capedel AS | Oslo | 2012 |
| Capedel Holding AS | Oslo | 2015 |
| Capio Anoreksi Senter AS | Kråkerøy | 1999 |
| Capio Fastleger AS | Oslo | 2022 |
| Capio Fastleger Rana AS | Mo I Rana | 2023 |
| Capio Norge Holding AS | Oslo | 2009 |
| Caracal AS | Tolvsrød | 2024 |
| Cardiocon AS | Oslo | 2006 |
| Cardiomed AS | Lillestrøm | 2019 |
| Cardiomyocyte AS | Haslum | 2021 |
| Care and Share Health AB | Se-703 75 Österbro | 2018 |
| Care Avlastning AS | Son | 2018 |
| Care of Golster AB Nuf | Se-132 37 Saltsjö-Boo | 2025 |
| Care of Ringerike AS | Hønefoss | 2024 |
| CARE4 Medical AS | Biri | 2021 |
| Careium Norge AS | Oslo | 2004 |
| Carl Berner Fysikalske Institutt Da | Oslo | 2000 |
| Carl Berner Legekontor AS | Oslo | 2023 |
| Carl Berner Legespesialistene AS | Oslo | 2024 |
| Carl Haukås Holding AS | Bergen | 2018 |
| Carlsten Holding AS | Skien | 2012 |
| Carmat AS | Mo I Rana | 2025 |
| Carolina Harboe AS | Stavanger | 2017 |
| Carolus Private Tannklinikk AS | Molde | 2024 |
| Carum AS | Ålgård | 2000 |
| Casmed AS | Skien | 2019 |
| Casper Holmberg Holding AS | Skien | 2019 |
| Cassiopeia Helse AS | Sandefjord | 2025 |
| Cathrine Amalie Bjørke AS | Oslo | 2022 |
| Cathrine Meyer Amundsen AS | Bergen | 2020 |
| Cathrine Sevre AS | Nesbyen | 2022 |
| Cathrine Trønnes Lie AS | Tistedal | 2023 |
| Causalinx AS | Sandnes | 2017 |
| Cav.Fra Medical AS | Kristiansand S | 2015 |
| CB Helse AS | Oslo | 2010 |
| Cbes Invest AS | Andenes | 2021 |
| Cbjelland Holding AS | Rådal | 2022 |
| Cbra AS | Billingstad | 2006 |
| CC Helse AS | Gjøvik | 2019 |
| CC Logopedi AS | Skien | 2025 |
| CC Vest Legesenter Da | Oslo | 2014 |
| CC Vest Medisinske Fotterapi AS | Oslo | 2017 |
| CC Vest Tannlegesenter AS | Oslo | 2002 |
| CCW Invest AS | Ranheim | 2020 |
| Cebre AS | Oslo | 2019 |
| Cecilie Augestad Holding AS | Ski | 2023 |
| Cecilie Dobloug Legetjenester AS | Oslo | 2026 |
| Cecilie Nilsen Holding AS | Horten | 2021 |
| Cecilie Strand AS | Bodø | 2006 |
| Cedolf AS | Oslo | 2013 |
| Cejsim AS | Stavanger | 2020 |
| Celins Los AS | Namsos | 2025 |
| Cellboost AS | Åkrehamn | 2026 |
| Cellmed Analytics AS | Kongsvinger | 2026 |
| Center Helse AS | Oslo | 2004 |
| Center Logopedi AS | Lillestrøm | 2020 |
| Centrum - Tannklinikk AS | Narvik | 2005 |
| Centrum Fastlegegruppe AS | Oslo | 2004 |
| Centrum Fysikalske AS | Sandefjord | 2012 |
| Centrum Fysioterapi AS | Fredrikstad | 2010 |
| Centrum Fysioterapi Ski Da | Ski | 2013 |
| Centrum Fysioterapi Storsteinnes AS | Storsteinnes | 2012 |
| Centrum Helse AS | Fredrikstad | 2016 |
| Centrum Legekontor Halden AS | Halden | 2008 |
| Centrum Legesenter AS | Oslo | 1991 |
| Centrum Tannklinikk II AS | Lillehammer | 2025 |
| Centrum Tannlegekontor AS | Krokkleiva | 2010 |
| Centrum Vaksiner AS | Sandnes | 1997 |
| Centrumsklinikken Eiendom AS | Tromsø | 1997 |
| Cepulis Ortopedi AS | Kongsvinger | 2025 |
| Ceratina AS | Oslo | 2018 |
| Cerccl Cinderella AS | Oslo | 2019 |
| Ces Holding AS | Egersund | 2021 |