| Cornwall Laser Clinic Ltd | Other services | 2020 |
| Cornwall Leadcraft Limited | Construction | 2026 |
| Cornwall Marina Limited | Transport & logistics | 2023 |
| Cornwall Mortgages Limited | Financial services | 2012 |
| Cornwall Motorhome Centre Ltd | Wholesale & retail | 2018 |
| Cornwall Physio Limited | Health & social care | 2019 |
| Cornwall Pools Limited | Administrative & support | 2005 |
| Cornwall Property Maintenance Ltd | Construction | 2024 |
| Cornwall Property Management Limited | Real estate | 2012 |
| Cornwall Property Services Limited | Real estate | 2018 |
| Cornwall Quantity Surveyors Ltd | Professional & scientific | 2023 |
| Cornwall Real Estate Limited | Real estate | 2019 |
| Cornwall Refuge Trust | Administrative & support | 2004 |
| Cornwall Roofing Services Ltd | Construction | 2023 |
| Cornwall Same Day Delivery Ltd | Transport & logistics | 2025 |
| Cornwall Scrap Store | Arts & recreation | 1994 |
| Cornwall Skin Clinic Ltd | Other services | 2023 |
| Cornwall Spray Plastering Ltd | Construction | 2023 |
| Cornwall Storage Solutions Ltd | Transport & logistics | 2019 |
| Cornwall Telecoms Ltd | Information & communication | 2014 |
| Cornwall Tile and Bathrooms Ltd | Wholesale & retail | 2021 |
| Cornwall Tool & Plant Hire Ltd | Administrative & support | 2025 |
| Cornwall Training and Consultancy Ltd | Administrative & support | 2015 |
| Cornwall Training Limited | Professional & scientific | 1976 |
| Cornwall Transfers Ltd | Hospitality | 2024 |
| Cornwall Waste Solutions Limited | Water & waste | 2016 |
| Cornwall's Airsoft & Army Surplus Ltd | Wholesale & retail | 2018 |
| Cornwhaul Ltd | Wholesale & retail | 2021 |
| Corporate Housing Limited | Construction | 1991 |
| Cosgarne Hall Limited | Hospitality | 2008 |
| Cosy Cove Cafe Ltd | Hospitality | 2026 |
| Cotswold Mobile Massage Ltd | Other services | 2026 |
| Cotton Close Management Company Limited | Real estate | 2020 |
| Counsellors Together CIC | Health & social care | 2014 |
| Country Explorer Limited | Transport & logistics | 2018 |
| Countrywide Signs Cornwall and Devon Ltd | Other services | 2025 |
| Courier Pigeon Ltd | Transport & logistics | 2022 |
| Cousin Jack South West Ltd | Real estate | 2024 |
| CQC Advice Ltd | Administrative & support | 2022 |
| Craftworx Design Limited | Professional & scientific | 2020 |
| Create Design South West Ltd | Professional & scientific | 2016 |
| Creghtyer Limited | Information & communication | 2024 |
| CRM Building Services Ltd | Construction | 2020 |
| Crosswinds Equestrian Ltd | Agriculture & fishing | 2012 |
| Crowle Property Partners Ltd | Real estate | 2024 |
| Crsg Project Services Ltd | Construction | 2023 |
| Crystal Clear Management Property Ltd | Administrative & support | 2024 |
| CS Barr Ltd | Professional & scientific | 2007 |
| Cubenet Limited | Construction | 2003 |
| Cubs Coffee Ltd | Wholesale & retail | 2020 |
| Curio Corner (Mevagissey) Ltd | Wholesale & retail | 2003 |
| Current. Clothing Ltd | Wholesale & retail | 2026 |
| Currian 1969 Limited | Extraterritorial | 2014 |
| Cynibre Holdings Ltd | Construction | 2023 |
| D S Williams Ltd | Construction | 2026 |
| D&A Plastering Limited | Construction | 2010 |
| D&H Properties (SW) Limited | Real estate | 2009 |
| D. MAY & SON Limited | Wholesale & retail | 1998 |
| D.L. Flowers Wholesale Ltd | Wholesale & retail | 2016 |
| Dace Property Limited | Hospitality | 2016 |
| Dalghennas Holdings Limited | Manufacturing | 2020 |
| Dalmac Motors Ltd | Wholesale & retail | 2026 |
| DAN Wade Welding and Fabrication Ltd | Manufacturing | 2017 |
| Dancing Reine 2019 Limited | Hospitality | 2019 |
| Daniel JOB Building & Roofing Contractor Ltd | Construction | 2020 |
| Daniels Lane 99 Limited | Hospitality | 2020 |
| Darnells Wealth Management Limited | Financial services | 2007 |
| Data Networking Ltd | Wholesale & retail | 2022 |
| Datavo Ltd | Information & communication | 2025 |
| Dave Hamley Electrical Limited | Construction | 2012 |
| DAW Couriers Ltd | Transport & logistics | 2022 |
| Dawat Indian Limited | Hospitality | 2024 |
| Dawn Chorus Consultants Ltd | Information & communication | 1995 |
| Dbbb Limited | Professional & scientific | 2010 |
| Dcbs ST Austell Limited | Professional & scientific | 2022 |
| DD Heavy Haulage Ltd | Transport & logistics | 2024 |
| Deaf Inclusivity Ltd | Health & social care | 2022 |
| Dean Hancock Plumbing & Heating Ltd | Construction | 2008 |
| Dean Lettings Limited | Real estate | 2015 |
| Deep Technical Ltd | Professional & scientific | 2025 |
| Defence Security Inductive Power Ltd | Professional & scientific | 2024 |
| Delvrys Limited | Arts & recreation | 2024 |
| Design to Product Ltd | Professional & scientific | 2023 |
| Detailing Design Ltd | Professional & scientific | 2026 |
| DEV Techblitz Ltd | Extraterritorial | 2025 |
| Devali Logistics Ltd | Transport & logistics | 2018 |
| Developmental Strategies Ltd | Professional & scientific | 2000 |
| Deviock Wine Company Limited | Manufacturing | 2007 |
| Devon & Cornwall Business Services Limited | Professional & scientific | 2000 |
| Devon & Cornwall Security Ltd | Administrative & support | 2019 |
| DH Marine Ltd | Manufacturing | 2025 |
| DHC Holdings Limited | Financial services | 2005 |
| Dial a Dog Wash Limited | Administrative & support | 2003 |
| Diamond GCL Limited | Construction | 2021 |
| Dimension Communications Limited | Professional & scientific | 2000 |
| Disco Beads Ltd | Wholesale & retail | 2013 |
| Discover Off-Road Limited | Administrative & support | 2026 |
| Disrupt Activewear Limited | Wholesale & retail | 2023 |
| DJS Landscapes Ltd | Administrative & support | 2021 |
| DJW Group Ltd | Real estate | 2021 |