| Craigmoor RTM Company Limited | Professional & scientific | 2015 |
| Cranstar Apartments Management Company Limited | Real estate | 2006 |
| Crantock Golf Limited | Hospitality | 2023 |
| Crantock Vale Management Company Limited | Extraterritorial | 2011 |
| Create West Country Ltd | Education | 2015 |
| Creating Waves DPT Limited | Manufacturing | 2023 |
| Creative Empowerment CIC | Health & social care | 2022 |
| Creative Planning (SW) Limited | Professional & scientific | 2014 |
| Creative Wealth Limited | Financial services | 2008 |
| Creativity Shack Ltd | Other services | 2020 |
| Credit Reporting Agency (Bidco) Limited | Administrative & support | 2020 |
| Credit Reporting Agency (EBT) Limited | Financial services | 2024 |
| Credit Reporting Agency (Holdco) Limited | Administrative & support | 2022 |
| Credit Reporting Agency Limited | Administrative & support | 1999 |
| Crittercull Ltd | Other services | 2021 |
| CRO Magnon Property Limited | Real estate | 2017 |
| Croft Design Collective LLP | | 2018 |
| Crombie Medical Management Ltd | Health & social care | 2010 |
| Croots ATS Ltd. | Agriculture & fishing | 2014 |
| Crossley Hill Limited | Professional & scientific | 2019 |
| Crowd Space Limited | Financial services | 2014 |
| Crowdjustice Ltd | Information & communication | 2023 |
| Crowncomm Ltd | Information & communication | 2025 |
| Crownmark Developments Limited | Construction | 1983 |
| Crownmark LLP | | 2022 |
| Croyde CC Limited | Financial services | 2025 |
| Crozid Limited | Health & social care | 2020 |
| Crumbles Cafe Limited | Hospitality | 2021 |
| Cruse Electrical Ltd | Construction | 2025 |
| Crusoes Management Company Limited | Households | 1986 |
| Crystal Coast Property Management Ltd | Administrative & support | 2024 |
| Crystal Sea Fishing Limited | Agriculture & fishing | 2012 |
| CT Power Solutions Ltd | Construction | 2016 |
| Cubert Advisory Limited | Information & communication | 2024 |
| Cubert Holywell Property Management Company Limited | Households | 2020 |
| Cubert Property Limited | Real estate | 2024 |
| Cultivating Peace Ltd | Other services | 2025 |
| Curio Shop Limited | Wholesale & retail | 2022 |
| Curry Inn Truro Ltd | Hospitality | 2022 |
| Curtis & Treleaven Ltd | Professional & scientific | 2014 |
| Cusho Ltd | Real estate | 2000 |
| Custom Build Cornwall Ltd | Construction | 2021 |
| CV Fire & Partitions Ltd | Construction | 2020 |
| CV Hvac Ltd | Manufacturing | 2021 |
| Cyberteam Security Services Limited | Information & communication | 2018 |
| Cybertrad Limited | Health & social care | 2008 |
| D & G Builders Cornwall Limited | Construction | 2010 |
| D & S Jose Limited | Construction | 2010 |
| D Brunt Consulting Ltd | Professional & scientific | 2023 |
| D E Stonework Limited | Manufacturing | 2025 |
| D H Continental Ltd | Transport & logistics | 2025 |
| D Harding Construction Limited | Construction | 2025 |
| D Hutchings Construction Limited | Construction | 2012 |
| D K Gupta Limited | Real estate | 2016 |
| D P J Painting and Decorating Ltd | Construction | 2023 |
| D.P.S. Electrical (Truro) Ltd | Wholesale & retail | 2003 |
| D.Taylor Electrical SW Ltd | Construction | 2021 |
| DA Bara ( ST Mawes) Limited | Hospitality | 2021 |
| DA Bara (Falmouth) Ltd | Hospitality | 2024 |
| DA Bara (Hogen DA) Ltd | Manufacturing | 2023 |
| DA Bara (RHL) Limited | Hospitality | 2017 |
| DA Bara Limited | Manufacturing | 2017 |
| Daisy Estates Limited | Real estate | 2002 |
| Daisy Fays Limited | Health & social care | 2013 |
| Daisy Hill Farm Ltd | Hospitality | 2020 |
| Daisy Residential Ltd | Real estate | 2018 |
| DAKOTA6 Limited | Administrative & support | 2012 |
| DAKOTA6 Properties Ltd | Construction | 2017 |
| Daltor Ltd | Health & social care | 2022 |
| Damax Group Ltd | Wholesale & retail | 2020 |
| DAN Jose Plumbing Services Ltd | Construction | 2022 |
| Daniel Beevers Dental Limited | Health & social care | 2014 |
| Daniell Assets Limited | Professional & scientific | 2019 |
| Daniell Holdings Limited | Financial services | 2023 |
| Danver Plumbing & Heating Limited | Construction | 2024 |
| Dark Cornwall Studio Ltd | Wholesale & retail | 2025 |
| Dark Folklore Ltd | Wholesale & retail | 2024 |
| Dark Horse Properties Limited | Professional & scientific | 2010 |
| Dark Horse Ventures Ltd | Professional & scientific | 2016 |
| Darlow Properties Limited | Construction | 2007 |
| Darren Bilkey Financial Planning Ltd | Financial services | 2019 |
| Datadean Limited | Information & communication | 1994 |
| Datahealth Consultancy Ltd | Financial services | 2000 |
| Datson Consulting Limited | Professional & scientific | 2009 |
| Davanna Heating Limited | Construction | 2002 |
| David Cole Developments Ltd | Professional & scientific | 2014 |
| David Cole Homes Limited | Financial services | 2018 |
| David Cole Property Ltd | Financial services | 2014 |
| David Curran Photography Ltd | Professional & scientific | 2018 |
| David Furze Dental Services Limited | Health & social care | 2012 |
| David Paull (CNC) Engineering Limited | Manufacturing | 2002 |
| David Paull Holdings Limited | Financial services | 2017 |
| Davies MAY Ltd | Construction | 2017 |
| Davies MAY Project Management LLP | | 2022 |
| Dawson Partnership Limited | Construction | 2014 |
| DAX Warner Ltd | Construction | 2024 |
| Daza Consulting Limited | Health & social care | 2017 |
| DB Hayle Consulting Limited | Professional & scientific | 2018 |
| DC Electrical & Services Limited | Construction | 2024 |
| DCD (ST. Marina) Ltd | Professional & scientific | 2017 |