| Colestocks Barns Management Company Limited | Households | 2016 |
| Combe Estate Gittisham LLP | | 2025 |
| Common Sense Communicating Limited | Professional & scientific | 2017 |
| Commonwealth Construction LLP | | 2024 |
| Commonwealth Trading Partnership LLP | | 2023 |
| Compliance Drive Ltd | Professional & scientific | 2020 |
| Conserve Plumbing, Heating and Renewables Ltd | Construction | 2022 |
| Continuing Airworthiness Support Limited | Manufacturing | 2016 |
| Cooking Enterprises Limited | Hospitality | 2014 |
| Cool Heat South West Limited | Construction | 2016 |
| Cooler Commercials Ltd | Wholesale & retail | 2019 |
| Cornhill Management Company Limited | Real estate | 2005 |
| Cornish Pride Engineering Ltd | Professional & scientific | 2026 |
| Cosmodent Ltd | Health & social care | 2024 |
| Countdown Creative Ltd | Information & communication | 2020 |
| Crafty Otter Campers Ltd | Manufacturing | 2021 |
| Critchell Roofing Limited | Construction | 2002 |
| Crystal Clear Cleaning Services (Devon) Limited | Other services | 2003 |
| CSM Independence Ltd | Hospitality | 2014 |
| Culm Valley Mills LLP | | 2002 |
| CW Build Limited | Construction | 2015 |
| D & S Watts Holding Limited | Real estate | 2021 |
| D J J M Construction Limited | Construction | 2016 |
| D.G.I. Electrical Limited | Other services | 2017 |
| D.W. Olive Limited | Agriculture & fishing | 2000 |
| D3 Farming Limited | Agriculture & fishing | 2017 |
| Daisy's Distributions Ltd | Wholesale & retail | 2025 |
| Dalstock Property Co. Limited | Construction | 1974 |
| Damoris Ltd | Professional & scientific | 2025 |
| Danebury Building Services (Devon) Limited | Construction | 1984 |
| Daniel James Homes Ltd | Construction | 2019 |
| Dares Surfacing Ltd | Construction | 2019 |
| Dares Surfacing Somerset Limited | Other services | 2019 |
| Darryl-Robert Aesthetics Academy Ltd | Education | 2024 |
| DB Devon Services Ltd | Wholesale & retail | 2023 |
| DB Group Solutions Ltd | Wholesale & retail | 2025 |
| DC Plumbing and Heating Industries Limited | Construction | 2024 |
| DC Watchmaker Limited | Other services | 2008 |
| DCB Tax Ltd | Professional & scientific | 2018 |
| DCB Tax Services Ltd | Professional & scientific | 2021 |
| Deborah House Management Limited | Households | 2004 |
| Deep DIG Limited | Construction | 2018 |
| Deer Park Country House Ltd | Hospitality | 1982 |
| Dekon Solutions Ltd | Manufacturing | 2022 |
| Devon Cattle Breeders Society | Other services | 1884 |
| Devon Drinks Solutions Limited | Manufacturing | 2023 |
| Devon Freewheelers EMS Limited | Health & social care | 2020 |
| Devonshire Poultry Holdings Limited | Real estate | 2008 |
| Devonshire Poultry Limited | Agriculture & fishing | 2001 |
| Devonvale Limited | Manufacturing | 2002 |
| DG Modelling Ltd | Professional & scientific | 2020 |
| Diaspora Investments Limited | Professional & scientific | 2006 |
| Dichrotech Limited | Professional & scientific | 2003 |
| Diogo Martins Ribeiro Ltd | Health & social care | 2015 |
| Disco Property Holdings Limited | Real estate | 2022 |
| DKD Optical Ltd | Wholesale & retail | 2018 |
| DLO Development Ltd | Construction | 2025 |
| Dmzee Limited | Construction | 2025 |
| Dodge Holdings Ltd | Financial services | 2026 |
| Dog N Bone Consulting Ltd | Professional & scientific | 2020 |
| Domus Devon Ltd | Construction | 2015 |
| Door Doctors Limited | Manufacturing | 2004 |
| Drakes Plumbing and Heating South West Ltd | Construction | 2025 |
| Dreamland Properties Ltd. | Real estate | 1992 |
| Drogan Limited | Real estate | 1987 |
| Drug Expert Limited | Professional & scientific | 2023 |
| DS Wholesalers Ltd | Wholesale & retail | 2019 |
| DTI Trading Limited | Administrative & support | 2003 |
| Dunkeswell Kart Club Ltd | Arts & recreation | 2023 |
| Dunkeswell Raceway Ltd | Hospitality | 2023 |
| Dunkeswell Trading Ltd | Construction | 2019 |
| Duralife Windows Limited | Construction | 2000 |
| E Future Homes Ltd | Professional & scientific | 2012 |
| E-Solent Ltd | Wholesale & retail | 2021 |
| Earz Ltd | Health & social care | 2011 |
| East Devon 4 X 4 Limited | Arts & recreation | 2002 |
| East Devon and Somerset Removals Ltd | Transport & logistics | 2025 |
| East Devon and Somerset Storage Ltd | Transport & logistics | 2024 |
| East Devon Buildings Ltd | Construction | 2019 |
| East Devon Developments Ltd | Construction | 2024 |
| East Devon Environmental Services Limited | Water & waste | 2025 |
| East Devon Estate Agents Limited | Real estate | 2005 |
| East Devon Scaffolding Limited | Construction | 2006 |
| Easy Call Communications Limited | Wholesale & retail | 2010 |
| Easy Grow Automations Ltd | Information & communication | 2025 |
| Easymatch Limited | Information & communication | 2012 |
| Eaton Property Investment Limited | Real estate | 2005 |
| Ecowheel Taxi Ltd | Transport & logistics | 2021 |
| Ecowheeltrade Ltd | Wholesale & retail | 2023 |
| ED and Becky Properties Limited | Real estate | 2020 |
| Edifice Property Limited | Real estate | 2023 |
| Efavet Services Ltd | Professional & scientific | 2022 |
| Elan Associates Ltd | Professional & scientific | 2020 |
| Eldercare Systems Ltd | Administrative & support | 2019 |
| Eleanor Kershaw Homecare Assistant Ltd | Health & social care | 2021 |
| Electric Azimuth Limited | Information & communication | 2021 |
| Elements Brand Management Limited | Information & communication | 2023 |
| Elevated Vision Limited | Information & communication | 2022 |
| Eleven Ideas Limited | Information & communication | 2011 |
| Eleven X Limited | Information & communication | 2013 |