| Canine Hair and Beauty Ltd | Other services | 2022 |
| Carbon Fitness Cornwall Ltd | Arts & recreation | 2025 |
| Carbon Fitness Training CIC | Other services | 2025 |
| Cargo@Porthleven Ltd | Hospitality | 2025 |
| Carpenters 1964 Limited | Extraterritorial | 2014 |
| Carswell Electrical Ltd | Construction | 2023 |
| Cavalier Sports & Teamwear Ltd | Wholesale & retail | 2017 |
| CB Plastering (SW) Ltd | Construction | 2019 |
| Celtic Improvements Ltd | Construction | 2021 |
| Chandler's Plaice Limited | Hospitality | 2015 |
| Chapel Smiles Limited | Health & social care | 2024 |
| Chapel Street Boutique LLP | | 2016 |
| Cheshire Living Limited | Construction | 2003 |
| Children Beyond Breakup Limited | Health & social care | 2024 |
| CHY Cleaning Company Ltd | Administrative & support | 2026 |
| CHY Fridays Ltd | Administrative & support | 2025 |
| Chylehan Management Company Limited | Households | 2021 |
| Clad-Um Ltd | Construction | 2022 |
| Classic Motors Cornwall Ltd | Wholesale & retail | 2021 |
| Claudia Caolin Dance and Entertainment CIC | Arts & recreation | 2018 |
| Clean DD Limited | Transport & logistics | 2022 |
| Cleanno Cleaning Services Ltd | Administrative & support | 2024 |
| Clearview Glass & Glazing Limited | Manufacturing | 2003 |
| Clive Brown Automotive Engineer Limited | Wholesale & retail | 2007 |
| CLU Logistics Ltd | Construction | 2022 |
| Coaside Interiors Ltd | Professional & scientific | 2024 |
| Comfish Marine Ltd | Wholesale & retail | 2023 |
| Complete Language Solutions Ltd | Administrative & support | 2013 |
| Connecting Send CIC | Information & communication | 2026 |
| Contract Flooring Holdings Limited | Construction | 2015 |
| Coolboard Ltd | Manufacturing | 2007 |
| Cornish Blooms Limited | Agriculture & fishing | 2020 |
| Cornish Stone Construction Limited | Construction | 2025 |
| Cornish Trailers Limited | Manufacturing | 2013 |
| Cornwall African and International Food Store Ltd | Wholesale & retail | 2024 |
| Cornwall Autorides Ltd | Transport & logistics | 2025 |
| Cornwall Bespoke Ltd | Construction | 2023 |
| Cornwall Chamber of Commerce | Administrative & support | 1988 |
| Cornwall Consultants Ltd. | Professional & scientific | 2002 |
| Cornwall Couriers Ltd | Transport & logistics | 2022 |
| Cornwall Mining Consultants Limited | Extraterritorial | 2022 |
| Cornwall Outdoor Solutions Ltd | Administrative & support | 2025 |
| Cornwall Sash Restorations Limited | Construction | 2024 |
| Cornwall Window & Conservatory Centre Ltd | Manufacturing | 2014 |
| CORNWALL1 Ltd | Wholesale & retail | 2022 |
| Corrin Design & Construction Ltd | Construction | 2014 |
| County Property Finders Ltd | Professional & scientific | 2021 |
| Cove Carpentry and Interiors Ltd | Construction | 2024 |
| Cove Electrical Ltd | Construction | 2025 |
| Cowley Stone & Slate Ltd | Manufacturing | 2018 |
| Cozycash Investments Ltd | Financial services | 2022 |
| CPH (South West) Management Company Limited | Real estate | 2026 |
| CPS Solutions Cornwall Limited | Administrative & support | 2019 |
| Create (Cornwall) C.I.C. | Arts & recreation | 2020 |
| Creative CAD Ltd | Professional & scientific | 2007 |
| CREW2U Limited | Arts & recreation | 2016 |
| Cristea Builders Ltd | Construction | 2025 |
| Cro-Mar Solutions Ltd | Professional & scientific | 2024 |
| Croft Common Estates Ltd | Construction | 2024 |
| Crofty Education Trust | Education | 2016 |
| Crougy & Co Limited | Professional & scientific | 2019 |
| CS Aviation Ltd | Manufacturing | 2024 |
| Cultura Live Food Ltd | Manufacturing | 2025 |
| Curry Mela Ltd | Hospitality | 2024 |
| D&R Automotive Ltd | Wholesale & retail | 2023 |
| Daryl John Consulting Ltd | Administrative & support | 2025 |
| Databymaisie Ltd | Construction | 2023 |
| David Hendy Funeral Services Limited | Other services | 2003 |
| David Ruse Ltd | Administrative & support | 2017 |
| DB Law Solicitors LLP | | 2018 |
| DBC Building Contractor Ltd | Construction | 2024 |
| Deborah Nadine Pethick Ltd | Extraterritorial | 2026 |
| Dellamont Ltd | Health & social care | 2021 |
| Deryk Hamilton Pooley Ltd | Extraterritorial | 2024 |
| Destination Cornwall Ltd | Professional & scientific | 2026 |
| Devine Ultra Care Ltd | Public administration | 2023 |
| Diamond CUT Renovations Ltd | Construction | 2024 |
| Digilink Connect Services Ltd | Information & communication | 2024 |
| DIY Machines Limited | Professional & scientific | 2019 |
| DJ Electrical (SW) Ltd | Construction | 2009 |
| DLK Education Ltd | Administrative & support | 2026 |
| Dlpcivils Ltd | Construction | 2025 |
| Dolcoath Motors (Holdings) Ltd | Wholesale & retail | 2021 |
| Dominic & Kevin Ltd | Administrative & support | 2019 |
| DR a Coppola Ltd | Health & social care | 2020 |
| DR25 Limited | Professional & scientific | 2020 |
| Dragon Construct Ltd | Construction | 2022 |
| Dreamshack Limited | Wholesale & retail | 2018 |
| Drillserve Limited | Manufacturing | 1979 |
| Droskyn Surf Company Limited | Wholesale & retail | 2025 |
| DRS Incorporated Ltd | Real estate | 2026 |
| DRT Rentals Ltd | Real estate | 2022 |
| DT Carpentry and Construction Limited | Construction | 2023 |
| Duchy Creative Print Limited | Wholesale & retail | 2018 |
| Duchy Developments Ltd | Construction | 2020 |
| Duchy Electrical Ltd | Administrative & support | 2018 |
| Duchy Fire Protection Limited | Public administration | 2025 |
| Duckeye Limited | Information & communication | 2008 |
| Duvet Days Cornwall Ltd | Other services | 2021 |
| E Laity Limited | Construction | 2020 |