| Containerservicen Transport AS | Larvik | 2000 |
| Contego AS | Oslo | 2017 |
| Contigo Services AS | Gan | 2023 |
| Contitech Transportbandsysteme GmbH | De-30165 Hannover | 2020 |
| Contractair Ltd | Worcestershire Dy10 4Jb | 2025 |
| Contracto AS | Gibostad | 2026 |
| Contractus LT Uab | Lt-08119 Vilnius | 2015 |
| Contrast Adventure Norway AS | Sunndalsøra | 2007 |
| Contrast Håndverk AS | Drammen | 2005 |
| Contrasto AS | Harstad | 2016 |
| Control Consult AS | Oslo | 1991 |
| Control Cutter Limited | Aberdeen Ab10 6Sd Scotland | 2024 |
| Control Seal BV | 9900 Ah Appingedam | 2010 |
| Convene AS | Sandane | 2010 |
| Convene Finans AS | Førde | 1990 |
| Convene Holding AS | Sandane | 2017 |
| Conwy Valley Consortium Limited | Ll31 9Bw Conwy | 2008 |
| Cool Company Norge AS | Oslo | 2015 |
| Cooley Food Consultants Ltd | Dundalk Co Louth | 2013 |
| Coop Obs! Hypermarked SA | Oslo | 1998 |
| Coop Prix SA | Oslo | 1998 |
| Coor Cleaning Catering and Property AS | Lysaker | 2013 |
| Coor Service Management AS | Oslo | 2001 |
| Coor Service Management Øst AS | Lysaker | 1975 |
| Copernicus AS | Halden | 2019 |
| Copperfield Rekruttering Og Rådgivning AS | Oslo | 2022 |
| Cora Service Og Megling AS | Hamar | 2018 |
| Coratti Og Tesdal AS | Bergen | 2020 |
| Corbu AS | Bjerkvik | 2017 |
| Cordelia Sail AS | Horten | 2024 |
| Cordinator Da | Nøtterøy | 1996 |
| Core Aviation Limited | Swords County Dublin | 2015 |
| Core Security AS | Nesbru | 2013 |
| Core Utleie AS | Gamle Fredrikstad | 2022 |
| Coreavia AS | Haslum | 2013 |
| Coretrax Global Limited Norway Nuf | Tananger | 2021 |
| Coretto Byggdrift AS | Sandnes | 2021 |
| Coreworks AS | Sem | 2025 |
| Corleonis SP. Zoo S.K.A | 84-230 Rumia | 2019 |
| Corporate Charity Management AS | Oslo | 2021 |
| Corporate Cup AS | Mandal | 2018 |
| Corporate Partners AS | Oslo | 2015 |
| Cortendo Invest AB | 30108 Halmstad | 2008 |
| Cortex Facaderens | Dk-2650 Hvidovre | 2023 |
| Corus Byggesystemer | 8400 Ebeltoft | 2006 |
| Corvara Industri- Och Skadeservice AB | Oslo | 2013 |
| Corvus Consulting AS | Oslo | 1998 |
| Corylus AS | Fjellstrand | 2005 |
| Cosmic AS | Oslo | 1997 |
| Costa Services AS | Stavanger | 2021 |
| Costa Solution AS | Trondheim | 2005 |
| Costrar | Bg-1463 Sofia Sofia-Grad | 2022 |
| Costsavers AS | Drammen | 2012 |
| Cotrack Rental AS | Fjellhamar | 2026 |
| Cover.Vision AS | Laksevåg | 2025 |
| Cowberry AS | Tistedal | 2014 |
| Cpbp Trading Limited | Middlesbrough Ts4 2Ng England | 2024 |
| CPC Brand AS | Oslo | 2022 |
| CPM Construction Nuf | Lt-90153 Plunge | 2022 |
| Craftpower Oü | 12911 Tallinn City | 2015 |
| Cram AS | Oslo | 2016 |
| Cramo AB Nuf | Se-169 74 Solna | 2026 |
| Cramo AS | Oslo | 1988 |
| Cranbalt Norge AS | Oslo | 2020 |
| Crane AS | Krokelvdalen | 2025 |
| Crane Norway Oslo AS | Nannestad | 2016 |
| Crane Norway Rental AS | Sandnes | 2025 |
| Crane Process Flow Technologies Ltd | Gwent Np44 3Xx | 2006 |
| Craneway AS | Oslo | 2025 |
| Crawton Park Ltd | Aberdeenshire Ab39 2Tu Scotland | 2024 |
| Crazy Food AS | Åsgårdstrand | 2023 |
| Creaman AS | Oslo | 2017 |
| Creati AS | Drøbak | 2003 |
| Creative Media Group AS | Fredrikstad | 2024 |
| Creative Meetings Unlimited I Stockholm AB Nuf | Se-114 44 Stockholm | 2026 |
| Creative Technology Finland OY | Fi-02630 Espoo | 2016 |
| Creative Technology Northern Europe AB Nuf | Se-442 17 Kungälv | 2010 |
| Cred AS | Nesøya | 2019 |
| Credibility Lie Detection Technology Nuf | Strusshamn | 2018 |
| Credicare AS | Førde | 1987 |
| Crediflow AB | Se-252 20 Helsingborg | 2021 |
| Credit Solutions Nuf | Førde | 2013 |
| Creditsafe Norway AS | Oslo | 2014 |
| Credo Vekst AS | Stokke | 2006 |
| Credosoft Limited | G33 4En | 2010 |
| Creemore Consultants Limited | Cork | 2015 |
| Creo Service SA | Brønnøysund | 2010 |
| Creptio AS | Stranda | 2017 |
| Crewmate AS | Kristiansand S | 2022 |
| Cri AS | Bjørnevatn | 2026 |
| Crisco Subsea AS | Stavanger | 2023 |
| Cristina Renhold AS | Mosjøen | 2025 |
| Critical Facilities Solutions B.V. | Nl-1043Nx Amsterdam | 2026 |
| Crockatt Consultants Limited | Aberdeenshire Ab31 5Ee | 2014 |
| Croft Golfsimulator AS | Stathelle | 2025 |
| Crossmark Holding AS | Oslo | 1998 |
| Crossroad Travels AS | Skedsmokorset | 2025 |
| Crowberry Bush AS | Øverbygd | 2025 |
| Crown Tours Norway AS | Bergen | 2026 |
| Crudecorp AS | Haugesund | 2007 |