| CAVE2 Limited | Hospitality | 2025 |
| CB (South West) Limited | Hospitality | 2013 |
| Celtic Drilling Limited | Mining & quarrying | 2017 |
| Celtic Heat Ltd | Construction | 2023 |
| Celtic Horizon Properties Ltd | Real estate | 2025 |
| Celtic Security Solutions Ltd | Manufacturing | 2025 |
| Celtic Tuning (Derby) Limited | Wholesale & retail | 2020 |
| Celtic Tuning Limited | Information & communication | 2010 |
| Central Newquay Foods Ltd | Hospitality | 2025 |
| Centre Point Tiling Ltd | Construction | 2023 |
| Certus Biomedical Ltd | Wholesale & retail | 2019 |
| CG Properties Limited | Real estate | 1999 |
| Chanel's Cakery Ltd | Wholesale & retail | 2022 |
| Chapel Farm (Newquay) Limited | Agriculture & fishing | 1962 |
| Charlotte Harris Consulting Limited | Administrative & support | 2018 |
| Charlottesbuisness Limited | Agriculture & fishing | 2025 |
| Charlton Property Limited | Hospitality | 2015 |
| Charlton Robertson Holdings Ltd | Financial services | 2022 |
| Chartwood Planning Ltd | Professional & scientific | 2015 |
| Chegwin Court Management Company Limited | Households | 2006 |
| Chelstow Leisure Limited | Hospitality | 2002 |
| Chi-An-Mor Management Company Limited | Real estate | 2015 |
| Chicoco Services Limited | Administrative & support | 2023 |
| Chill at the Mill Ltd | Arts & recreation | 2013 |
| Choffee Limited | Manufacturing | 2024 |
| Chogaleenterprises Ltd | Wholesale & retail | 2025 |
| CHP Sourcing Ltd | Administrative & support | 2025 |
| Chris Angove Heating Ltd | Administrative & support | 2004 |
| Chris Swabey Limited | Construction | 2002 |
| Christensen International Limited | Manufacturing | 2024 |
| Christie Build Limited | Construction | 2019 |
| Chubby Wheels Ltd | Manufacturing | 2021 |
| Churchgate Developments (Mid-Cornwall Housing) Limited | Construction | 2017 |
| Churchgate Developments Limited | Construction | 1985 |
| CHY Lowen Early Years and Pre-School Ltd | Health & social care | 2020 |
| Chy-An-Eglos Limited | Real estate | 2004 |
| Chynance Accountancy Services Ltd | Professional & scientific | 2019 |
| Chynance Holdings Ltd | Real estate | 2020 |
| Chynoweth Lodge Limited | Hospitality | 2001 |
| Chyvarloe Limited | Real estate | 2024 |
| City Ceramics Dental Laboratory Limited | Manufacturing | 2008 |
| CJI Supply Chain Solutions Ltd | Professional & scientific | 2023 |
| Clarendon Court (Newquay) Management Limited | Households | 1987 |
| Clarissa Nails (UK) Limited | Other services | 2015 |
| Clatworthy Developments (Lanner) Ltd | Construction | 2025 |
| Clatworthy Holdings Ltd | Real estate | 2024 |
| Clean Lines Wetsuits Limited | Wholesale & retail | 2020 |
| Clean Sea Newquay CIC | Other services | 2025 |
| Cleo Fabrics Ltd | Wholesale & retail | 2015 |
| Cliff Edge Leaseholders RTM Company Limited | Households | 2025 |
| Cliff Road Newquay Limited | Households | 2017 |
| Clint's Barbers Ltd | Other services | 2018 |
| Cloud Nine Works Limited | Information & communication | 2011 |
| Clovelly House Care Home Limited | Health & social care | 2013 |
| Clover Bars and Restaurants Ltd | Hospitality | 2023 |
| Coast & Country Solutions Ltd | Construction | 2025 |
| Coast Freehold Limited | Extraterritorial | 2011 |
| Coast Hill Property Ltd | Real estate | 2023 |
| Coast Publishing Limited | Information & communication | 2005 |
| Coast to Coast Surveying (SW) Ltd | Professional & scientific | 2023 |
| Coastal Crusaders Community Interest Company | Education | 2019 |
| Coastal Escapes Ltd | Real estate | 2021 |
| Coastal View Management Company Limited | Households | 2019 |
| Cockayne Properties Ltd | Real estate | 2016 |
| Coco Interiors Group Ltd | Professional & scientific | 2023 |
| CODE4GOLD Limited | Information & communication | 2020 |
| Cognitive Design Solutions Limited | Education | 2014 |
| Cognos Consulting Limited | Administrative & support | 2012 |
| Collins Marketing Agency Ltd | Professional & scientific | 2026 |
| Colro-Green Developments Limited | Construction | 1977 |
| Colyvale Foods Limited | Professional & scientific | 2001 |
| Comacc Ltd | Professional & scientific | 2007 |
| Commercial Relocation Services Limited | Transport & logistics | 2011 |
| Common Parlance Ltd | Professional & scientific | 2015 |
| Compass North Services Limited | Health & social care | 2010 |
| Compton Products Limited | Manufacturing | 1996 |
| Concrete Waves Newquay Limited | Hospitality | 2024 |
| Conformance Solutions Ltd | Administrative & support | 2017 |
| Consultfin Limited | Professional & scientific | 2014 |
| Contact Front Clothing Ltd | Wholesale & retail | 2024 |
| Cool by the Pool Limited | Wholesale & retail | 2013 |
| Cooper's Financial Planning Ltd | Financial services | 2024 |
| Coops Club Ltd | Wholesale & retail | 2023 |
| Core Commercial Developments Ltd | Construction | 2023 |
| Core Event Hire Ltd | Information & communication | 2021 |
| Cornish Appartments Ltd | Real estate | 2024 |
| Cornish Art Emporium Ltd | Arts & recreation | 2025 |
| Cornish Builders Ltd | Construction | 2020 |
| Cornish Chough Development Residents Association Limited | Households | 2025 |
| Cornish Coast Cleaning Co Ltd | Administrative & support | 2026 |
| Cornish Coast Renovations Ltd | Construction | 2021 |
| Cornish Coast Retreats Limited | Hospitality | 2019 |
| Cornish Coastal Retreats Ltd | Hospitality | 2025 |
| Cornish Cream Liqueurs Ltd | Wholesale & retail | 2023 |
| Cornish Cream Newquay Limited | Wholesale & retail | 2012 |
| Cornish Cream ST Ives Ltd | Wholesale & retail | 2010 |
| Cornish Cycle Tours Limited | Administrative & support | 2011 |
| Cornish Engraving Ltd | Manufacturing | 2023 |
| Cornish Events Limited | Administrative & support | 2015 |
| Cornish Firebox Ltd | Manufacturing | 2024 |