| D&R Properties Cornwall Ltd | Real estate | 2023 |
| D. R. Building Enterprises Limited | Wholesale & retail | 1986 |
| Daesthetic Ltd | Other services | 2025 |
| Daimla Limited | Real estate | 2002 |
| Daisy Bear Protection and Legal Services Limited | Professional & scientific | 2025 |
| Dales Cornwall Limited | Wholesale & retail | 2013 |
| DAN Ward Photography Ltd | Professional & scientific | 2015 |
| Darric Holdings Limited | Construction | 2024 |
| DAS Structures Limited | Professional & scientific | 2010 |
| Dash Convenience Stores Limited | Wholesale & retail | 2012 |
| Dash Group (SW) Limited | Professional & scientific | 2012 |
| Dash Logistic Services Limited | Transport & logistics | 2012 |
| Dash Vehicle Solutions Limited | Wholesale & retail | 1998 |
| Davey Sycamore Building Contractors Limited | Construction | 2016 |
| David Howard Lanyon Ltd | Extraterritorial | 2025 |
| David Reynolds Building Preservation Limited | Construction | 2016 |
| Davies Rural Property Consultants Limited | Professional & scientific | 2018 |
| Dawes & Windows Limited | Construction | 2007 |
| Dawn PVT Ltd | Hospitality | 2025 |
| DCM (Cornwall) Limited | Financial services | 2013 |
| DCV Recruitment Limited | Administrative & support | 2009 |
| Dead Man's HUT Ltd | Manufacturing | 2023 |
| Deborah Cooper and Sons Limited | Construction | 2026 |
| Deliver-E- Wizard Ltd | Transport & logistics | 2021 |
| Delizha Limited | Administrative & support | 2024 |
| Deluxx Live Limited | Arts & recreation | 2025 |
| Demoda Organic Hair & Beauty (Redruth) Ltd | Other services | 2016 |
| Demoda Organic Hair & Beauty (Truro) Ltd | Other services | 2016 |
| Derril Water Solar Limited | Energy | 2016 |
| Designstudiosw Ltd | Professional & scientific | 2019 |
| DG Self Storage Ltd | Real estate | 2024 |
| Differnet Digital Limited | Information & communication | 2005 |
| Ditcheat Solar CIC | Energy | 2024 |
| Divaano Limited | Construction | 2017 |
| DM Property Redruth LLP | | 2009 |
| DMD Renovations Limited | Construction | 2018 |
| DMT Education Limited | Education | 2020 |
| DN Manship Construction Limited | Construction | 2026 |
| DOE & Co Cornwall Ltd | Construction | 2023 |
| Dolphin Aerotech Ltd | Manufacturing | 2007 |
| Donaldson-Miller Ltd | Manufacturing | 2005 |
| Drakes Small Repairs Ltd | Other services | 2026 |
| Drillmac International Limited | Wholesale & retail | 2005 |
| Driverhead Limited | Education | 2024 |
| Dropzone Competitions Ltd | Information & communication | 2025 |
| Droskyn Castle Management Limited | Households | 1993 |
| DSM RGN Ltd | Health & social care | 2019 |
| DT Coaching Services Limited | Education | 2021 |
| Duchy Brass Ltd | Wholesale & retail | 2022 |
| Duchy Crossfit Limited | Arts & recreation | 2016 |
| Duchy Defibrillators Ltd | Administrative & support | 2019 |
| Duchy Fasteners Limited | Wholesale & retail | 1997 |
| Duchy Food Ltd | Hospitality | 2022 |
| Duchy Gemstones Limited | Wholesale & retail | 2026 |
| Duchy Kitchens Ltd | Wholesale & retail | 2025 |
| Duchy Veterinary Limited | Professional & scientific | 2011 |
| Dune Breeze Cleaning Services Ltd | Other services | 2024 |
| Dunstan Meadows 1958 Limited | Extraterritorial | 2014 |
| Duoduo Limited | Hospitality | 2025 |
| Durant Building and Roofing Limited | Construction | 2010 |
| DW Cook Transport Ltd | Transport & logistics | 2013 |
| DWN Limited | Wholesale & retail | 2012 |
| DWT (UK) Ltd | Construction | 2011 |
| DWT Group Limited | Real estate | 2026 |
| E. Mitchell & Sons Limited | Real estate | 1981 |
| Earlyyes Limited | Health & social care | 2016 |
| Earthbound Electrical Ltd | Construction | 2016 |
| Easterly Park Management Company Limited | Households | 2019 |
| Eastpointswest Limited | Professional & scientific | 2010 |
| EB Building Ltd | Construction | 2022 |
| Ebron FIN LLP | | 2016 |
| Ecowagon Ltd | Wholesale & retail | 2012 |
| ED Dyer Heating and Plumbing Limited | Construction | 2023 |
| ED Young Offshore Services Ltd | Mining & quarrying | 2026 |
| Eden Hot Tubs (Cornwall) Limited | Wholesale & retail | 2020 |
| Eden Hot Tubs (Devon) Limited | Wholesale & retail | 2026 |
| EDT Services Limited | Construction | 2006 |
| Edward T James & Company Limited | Financial services | 2008 |
| Egbeigwe Limited | Health & social care | 2023 |
| Electratest (UK) Ltd | Professional & scientific | 2001 |
| Electric Empire Ltd | Construction | 2023 |
| Electrical Installation Solutions SW Limited | Construction | 2021 |
| Elephant Rock Props & Games Ltd | Other services | 2019 |
| Elevate Dental Agency Ltd | Health & social care | 2022 |
| Eleven Basset Limited | Hospitality | 2021 |
| Elite Automotive SW Limited | Wholesale & retail | 2018 |
| Eljb Ltd | Hospitality | 2024 |
| Elliott Perioperative Solutions Ltd | Health & social care | 2022 |
| Ellis Event Power Services Limited | Construction | 2005 |
| Ellis Properties (Cornwall) Limited | Real estate | 2019 |
| Embedded Engineering Limited | Information & communication | 2004 |
| Emerald Psychology Limited | Health & social care | 2017 |
| EMI Developments Limited | Construction | 2017 |
| EMI Group (Holdings) Limited | Financial services | 2024 |
| EMI South West Limited | Construction | 2015 |
| Emily Denny Case Management Ltd | Health & social care | 2019 |
| Empty Valley Ltd | Administrative & support | 2019 |
| Encompass Aerial Surveying Ltd | Professional & scientific | 2024 |
| EQ Express Car Wash Ltd | Other services | 2024 |
| Equinox Business Ltd | Administrative & support | 2020 |