| Carrack Gladden Management Limited | Households | 1994 |
| Carrek Carpentry & Construction Limited | Construction | 2023 |
| Carrek Halen Construction Ltd | Construction | 2026 |
| Casebook Services Limited | Hospitality | 2017 |
| Cash Your Clutter Limited | Wholesale & retail | 2019 |
| Castle Brea Farm C.I.C. | Agriculture & fishing | 2022 |
| Cat Cruising Cornwall Limited | Transport & logistics | 2022 |
| Cattran & Hudson Limited | Financial services | 2013 |
| Cattran Trading Holdco Limited | Financial services | 2013 |
| Cattran Trading Limited | Real estate | 2006 |
| Cautionary Tale C.I.C. | Extraterritorial | 2023 |
| CB Childcare Consultancy Ltd | Information & communication | 2013 |
| Ccdl Innovation Ltd | Professional & scientific | 2018 |
| CD Cattran Limited | Financial services | 2013 |
| Celtic Cross Joinery Limited | Manufacturing | 2006 |
| Celtic Turf Limited | Agriculture & fishing | 2023 |
| Celtic-Pts Ltd | Health & social care | 2021 |
| CGS Contractors Southwest Limited | Administrative & support | 2003 |
| CGW Properties (SW) Ltd | Real estate | 2026 |
| Chaggar Cardiology Services Ltd | Real estate | 2020 |
| Chandlers (Mousehole) Limited | Households | 2018 |
| Chandos Estates Limited | Real estate | 1998 |
| Channel Crepes Ltd | Hospitality | 2025 |
| Chapel Street Properties Penzance Ltd | Real estate | 2025 |
| Chapel Street Studios Penzance Limited | Extraterritorial | 2022 |
| Charlie Goldsworthy Homes Limited | Construction | 2022 |
| Charter Software Limited | Information & communication | 2008 |
| Chelonia Limited | Manufacturing | 2005 |
| Choughed Estates Limited | Real estate | 2019 |
| Chris Bows Developments Limited | Construction | 1994 |
| Chris Burge Limited | Wholesale & retail | 2020 |
| Chris Nicholls Motors Limited | Wholesale & retail | 2001 |
| Chris Sedgeman Scaffolding Ltd. | Construction | 2000 |
| Chris Yacoubian Ltd | Information & communication | 2008 |
| Chrisalis Group Limited | Real estate | 2025 |
| Christian Camps in Wales Limited | Arts & recreation | 1999 |
| Christian Way Property Management Limited | Real estate | 2014 |
| Churchway Field Partnership Ltd | Agriculture & fishing | 2022 |
| CHY an BEL Limited | Real estate | 2025 |
| CHY an Porth (Penzance) Management Company Limited | Households | 2020 |
| CHY Kosel Ltd | Professional & scientific | 2022 |
| Chy-Ar-Venton Management Company Limited | Real estate | 2005 |
| Chygoose Estates Ltd | Real estate | 2020 |
| Chynoweth Developments Limited | Construction | 2018 |
| CIC Tribe Ltd | Professional & scientific | 2023 |
| Cinque Ports Developments Limited | Construction | 2022 |
| Ciptex Ltd | Information & communication | 2006 |
| Citizen Checkers CIC | Health & social care | 2020 |
| Cjls (Cornwall) Limited | Administrative & support | 2024 |
| Claires Northern Cafe Ltd | Hospitality | 2026 |
| Claraity Limited | Information & communication | 2025 |
| Clarence House Penzance Ltd | Real estate | 2011 |
| Clear View (South West ) Limited | Financial services | 2012 |
| Cliffe Consulting Limited | Professional & scientific | 2000 |
| Clockwork Media Limited | Information & communication | 2006 |
| Cloudlegal Limited | Extraterritorial | 2011 |
| Clough Ripley Ltd | Manufacturing | 2013 |
| CLP Anaesthetics Limited | Health & social care | 2017 |
| CLR Building & Decorating Services Limited | Construction | 2024 |
| CMC New Dawn Limited | Wholesale & retail | 2023 |
| Coach Haus Architecture Limited | Professional & scientific | 2022 |
| Coast & Garden Holidays Limited | Hospitality | 2019 |
| Coast 2 Coast Linen Hire Ltd | Other services | 2024 |
| Coast Activity Programme Ltd | Education | 2021 |
| Coast Community CIC | Health & social care | 2024 |
| COAST2COAST Construction Ltd | Construction | 2025 |
| Coastal Brocante Ltd | Wholesale & retail | 2024 |
| Coastal Building and Developments Ltd | Construction | 2016 |
| Coastline Action Sports C.I.C. | Arts & recreation | 2026 |
| Cobblestone Cottage Holidays Limited | Hospitality | 2014 |
| Cocoto Limited | Professional & scientific | 2013 |
| Coles Estates Ltd | Administrative & support | 2025 |
| Colin Curbishley Ltd | Arts & recreation | 2024 |
| Colin Stephens Limited | Construction | 2013 |
| Colquite Estate Limited | Other services | 1994 |
| Colquite Shooting Club Limited | Arts & recreation | 2018 |
| Compact-Baling Solutions UK Limited | Wholesale & retail | 2017 |
| Complete Cost Consultants Limited | Professional & scientific | 1999 |
| Completexsection Ltd | Health & social care | 2022 |
| Connections for Life CIC | Education | 2025 |
| Contact Electrical (South West) Limited | Construction | 2007 |
| Contact Power Limited | Construction | 2014 |
| Content Connect Limited | Information & communication | 2013 |
| Copperfoxpz Ltd. | Wholesale & retail | 2013 |
| Coralpay (UK) Limited | Professional & scientific | 2003 |
| Cork & Fork PNZ Ltd | Hospitality | 2021 |
| Cormoran Property Limited | Real estate | 2016 |
| Cornish Crown Limited | Manufacturing | 2008 |
| Cornish Democracy | Professional & scientific | 2025 |
| Cornish Family Holidays Ltd | Hospitality | 2017 |
| Cornish Heritage Company Limited(The) | Education | 1984 |
| Cornish Ice Company Limited | Manufacturing | 1991 |
| Cornish Marquee Hire Ltd | Administrative & support | 2019 |
| Cornish Mead Co.Limited | Manufacturing | 1957 |
| Cornish Meadow Limited | Hospitality | 2023 |
| Cornish Sardine Company Limited | Manufacturing | 2012 |
| Cornish Star Limited | Hospitality | 2024 |
| Cornish Traditional Builders Ltd | Construction | 2021 |
| Cornish Venning Limited | Professional & scientific | 2004 |
| Cornishwear Limited | Manufacturing | 2009 |