| Crisp Heating Ltd | Construction | 2025 |
| Cromartie Point Residents Limited | Households | 2003 |
| Crown Sports Lockers (UK) Limited | Manufacturing | 1990 |
| Custom Cladding Ltd | Construction | 2022 |
| CUT of Class Ltd | Other services | 2021 |
| Cutts & Luscombe Limited | | 1900 |
| CV Enterprises Ltd | Real estate | 2024 |
| Cvri Ltd | Financial services | 2023 |
| CX Arena Ltd | Professional & scientific | 2022 |
| Cycle Torbay C.I.C. | Manufacturing | 2022 |
| D Downing Spraying and Cleaning Limited | Administrative & support | 2023 |
| D Evans Plumbing Services Limited | Wholesale & retail | 2005 |
| D W & a W Property Services Limited | Real estate | 2016 |
| D'Clops Ltd | Administrative & support | 2020 |
| D.S.Churchill Construction Ltd | Construction | 2024 |
| DA Accessories Retail Ltd | Wholesale & retail | 2018 |
| Dacol Pvcu Ltd | Construction | 2000 |
| Dacol Scaffolding Limited | Construction | 2002 |
| Dainton Copse Forest School Community Interest Company | Education | 2022 |
| Dalmatian Property Ltd | Real estate | 2024 |
| DAN LEE Training Limited | Professional & scientific | 2010 |
| Dand Process Limited | Information & communication | 2018 |
| Danthemaninvestments Ltd | Real estate | 2025 |
| Daqlog Systems Limited | Information & communication | 2013 |
| Dari Housing Ltd | Real estate | 2025 |
| Darren Law Architecture Limited | Professional & scientific | 2012 |
| Dart Aero Ltd | Professional & scientific | 2021 |
| Dart Free Houses Limited | Professional & scientific | 1976 |
| Dart Health Limited | Arts & recreation | 2021 |
| Dart Investments SW Ltd | Real estate | 2021 |
| Dart Maritime Enterprise Limited (the) | Professional & scientific | 1976 |
| Dart Pleasure Craft Limited | Transport & logistics | 1972 |
| Dart Valley Properties Limited | Real estate | 2017 |
| Dart Valley Railway Ltd | Transport & logistics | 1965 |
| Dartington Financials Limited | Professional & scientific | 2018 |
| Dartington Leisure Limited | Hospitality | 2015 |
| Dartmoor Christmas Tree Farm Ltd | Agriculture & fishing | 2002 |
| Dartmoor Media Ltd | Arts & recreation | 2023 |
| Dartmoor Property Developments Limited | Construction | 2022 |
| Dartmouth Insurance Group (Consultants) Limited | Professional & scientific | 1967 |
| Dartside Joinery Ltd | Manufacturing | 2021 |
| Dartyl Ltd | Construction | 2021 |
| David Ripley Construction Ltd | Construction | 2026 |
| Davies & Bell Ltd | Professional & scientific | 2010 |
| DC Construction SW Limited | Manufacturing | 2021 |
| Dccs Panel CIC | Professional & scientific | 2021 |
| DCD Solutions Ltd | Financial services | 2024 |
| Dcmgmt Limited | Professional & scientific | 2025 |
| Decadent Designs Antique and Vintage Ltd | Wholesale & retail | 2023 |
| Deckscape Leisure Ltd | Construction | 2024 |
| Decorations and Celebrations Ltd | Wholesale & retail | 2013 |
| Defined Hosting Limited | Information & communication | 2016 |
| Desertbond Limited | Households | 1986 |
| Devi Mata Ltd | Hospitality | 2022 |
| Devon Countryside Ltd | Administrative & support | 2023 |
| Devon Details and Autocare Limited | Wholesale & retail | 2022 |
| Devon Diesel Society Limited | Other services | 1997 |
| Devon Dog Care Ltd | Agriculture & fishing | 2025 |
| Devon Magazine Company Ltd | Information & communication | 2013 |
| Devon Plant Drivers Ltd | Transport & logistics | 2018 |
| Devon Space and Time Removals Ltd | Water & waste | 2021 |
| Devon UK Foods Limited | Hospitality | 2015 |
| Devon's Finest Ltd | Hospitality | 2024 |
| Devon. C. Air Limited | Administrative & support | 2008 |
| Devonmade Design Ltd | Wholesale & retail | 2024 |
| Devonshire Window Systems Limited | Manufacturing | 1990 |
| Devonshire Windows Limited | Extraterritorial | 2015 |
| DHG Media Limited | Education | 2020 |
| Dhml Ltd | Hospitality | 2025 |
| Diamas Property Limited | Real estate | 2018 |
| Diamas Property Management Limited | Real estate | 2019 |
| Diamond Deliveries (SW) Ltd | Transport & logistics | 2016 |
| Diamond Training SW Ltd | Education | 2021 |
| Diana Walters Ltd | Arts & recreation | 2015 |
| Dians Stores Limited | Wholesale & retail | 2022 |
| Digital Background Limited | Information & communication | 2023 |
| Digital Background Solutions Limited | Information & communication | 2023 |
| Digital Creations Limited | Extraterritorial | 2004 |
| Digital Therapies Limited | Information & communication | 2025 |
| DJS Fish and Chips Ltd | Hospitality | 2020 |
| DM Dental Laboratory Ltd | Health & social care | 2017 |
| DMW Construction (Devon & Cornwall) Limited | Construction | 2020 |
| DNM Accounting & Tax Limited | Professional & scientific | 2024 |
| Dog & Soap Ltd | Other services | 2019 |
| Dolphin Court Management (Brixham) Limited | Households | 2009 |
| Don'T BE Roofless Limited | Construction | 2019 |
| Donto Marine Limited | Agriculture & fishing | 2017 |
| Door Logic Ltd | Construction | 2024 |
| Doorstep Arts CIC | Arts & recreation | 2013 |
| Dosson Limited | Real estate | 2015 |
| Doyle Dental Ltd | Health & social care | 2019 |
| Doyle Property NW Ltd | Real estate | 2024 |
| DR Bump (Torbay) Limited | Wholesale & retail | 2012 |
| DR Button Emdr Training Limited | Health & social care | 2025 |
| DR Hannah King Psychology Limited | Health & social care | 2023 |
| DR. P M Bavin Limited | Health & social care | 2002 |
| DRD Marine Services Ltd | Professional & scientific | 2018 |
| Drinkwater Services SW Ltd | Construction | 2023 |
| Drummond's Home Management Limited | Households | 2021 |
| Drumrauch Ltd | Hospitality | 2017 |