| Choconauts Limited | Wholesale & retail | 2011 |
| Chris Snell Ltd | Other services | 2019 |
| Chrome Accounts Ltd | Professional & scientific | 2020 |
| Churchills Electrical Limited | Construction | 2015 |
| CID Cosmetics Ltd | Wholesale & retail | 2017 |
| Cinac Ltd | Information & communication | 2020 |
| CJ Evans International Limited | Professional & scientific | 2009 |
| Clare Hart Consulting Ltd | Professional & scientific | 2025 |
| Clark Offshore Services Limited | Manufacturing | 2015 |
| Claxton Cabinetry Ltd | Manufacturing | 2021 |
| Claxton Hospitality Ltd | Hospitality | 2023 |
| Clear Purpose Ltd | Professional & scientific | 2023 |
| Clementine Cusack Films Ltd | Manufacturing | 2021 |
| Clenston Constructions Limited | Professional & scientific | 2018 |
| Clenston Estates Limited | Real estate | 2006 |
| Clenston Farmers Limited | Agriculture & fishing | 1964 |
| Cliff House RTM Company Limited | Households | 2020 |
| Close Advisory Ltd | Professional & scientific | 2024 |
| Cloud Clarity Limited | Information & communication | 2025 |
| Coast and Forest Education Limited | Education | 2021 |
| Coastal Tree & Access Ltd | Agriculture & fishing | 2021 |
| Cocker & Mastiff Limited | Hospitality | 2017 |
| Coco Holdings Ltd | Real estate | 2020 |
| Coeus Intelligence Group Ltd | Education | 2026 |
| Cole & Cole Surveying LLP | | 2026 |
| Collett Agricultural Engineering Ltd | Wholesale & retail | 2018 |
| Collett Electrical Services Ltd | Construction | 2010 |
| Complete Pest Solutions Ltd | Health & social care | 2019 |
| Concept Cables Limited | Manufacturing | 2002 |
| Concept Resilience Limited | Real estate | 2021 |
| Connect Contracting Limited | Construction | 2001 |
| Connexus Information Governance Limited | Information & communication | 2016 |
| Consega Limited | Information & communication | 2009 |
| Conservation Matters Ltd | Arts & recreation | 2014 |
| Controlio Ltd | Manufacturing | 2026 |
| Conygar Timber Company Limited | Wholesale & retail | 2020 |
| Core-Creative Services Ltd | Administrative & support | 2020 |
| Corico (International) Limited | Agriculture & fishing | 1982 |
| Corinthian Ventures Limited | Wholesale & retail | 2017 |
| Council of Milton Abbey School Limited(The) | Education | 1954 |
| Countryside Management Association C.I.C. | Other services | 2007 |
| Countryside Retreats Ltd | Hospitality | 2025 |
| County Cars Dorset Ltd | Transport & logistics | 2011 |
| Courtney Developments Limited | Construction | 1998 |
| Cowley Gems Limited | Professional & scientific | 2017 |
| Cowshedlabs Ltd | Information & communication | 2025 |
| CP Evolve Enterprises Ltd | Wholesale & retail | 2025 |
| Cpp-Usa Limited | Wholesale & retail | 2011 |
| Cprotech Limited | Professional & scientific | 2009 |
| Creditmax Ltd | Administrative & support | 1998 |
| Cricket Dorset Ltd | Arts & recreation | 2018 |
| Crossco (284) Limited | Professional & scientific | 1997 |
| Crossco (489) Limited | Extraterritorial | 2000 |
| Crowdcomms Group Limited | Information & communication | 2021 |
| Crowdcomms Ltd | Information & communication | 2011 |
| Crystal Lets Ltd | Real estate | 2021 |
| Csfx Trading Ltd | Information & communication | 2025 |
| CSK Trading Ltd | Wholesale & retail | 2011 |
| Ctek Battery Management UK Limited | Administrative & support | 2015 |
| Cutteridge Property Ltd | Real estate | 2025 |
| Cwservice (Dorset) Ltd | Manufacturing | 2018 |
| D and R Motion Ltd | Arts & recreation | 2023 |
| D B Parks Limited | Hospitality | 2019 |
| D D Carpet Cleaners Ltd | Other services | 2009 |
| D W Taylor & Sons Ltd | Agriculture & fishing | 1988 |
| D'Arcy Court Management Company Limited | Households | 2004 |
| Damory Consulting Limited | Information & communication | 2021 |
| Damory Garage Limited | Wholesale & retail | 1990 |
| Damory House Management Company Limited | Households | 2002 |
| Damory Mews Limited | Real estate | 2000 |
| Data First Agency Ltd | Information & communication | 2020 |
| Dave Handford Car Sales Limited | Wholesale & retail | 2004 |
| David Fennings 1969 Ltd | Construction | 2026 |
| DBB Consulting Limited | Financial services | 2003 |
| Dean Young Limited | Construction | 2026 |
| Debra Broadhurst Ltd | Other services | 2025 |
| Denmark Holdings Limited | Real estate | 2026 |
| Dent Diamond Ltd | Wholesale & retail | 2011 |
| Deutrom Dressage Horses Ltd | Agriculture & fishing | 2023 |
| Deutrom Equestrian Ltd | Agriculture & fishing | 2023 |
| Devendra & Bijay Ltd | Real estate | 2026 |
| DEX Ltd | Real estate | 2024 |
| Dexil Limited | Wholesale & retail | 2012 |
| DGM Truck and Plant Limited | Wholesale & retail | 2021 |
| Digi Technologies Ltd | Information & communication | 2026 |
| Dirtydog Dorset Co Ltd | Hospitality | 2021 |
| Disco Dancing Dog Ltd | Information & communication | 2019 |
| Disco Waffle Ltd | Wholesale & retail | 2020 |
| DK Adhd and Psychiatric Consultancy Services Ltd | Health & social care | 2021 |
| DMT Carpentry LP | | 2021 |
| Dog Star Helicopters Limited | Transport & logistics | 2011 |
| Dolce Amore Italiano Limited | Hospitality | 2026 |
| Dormant Company 11438846 Ltd | Administrative & support | 2018 |
| Dorset AI Services Ltd | Information & communication | 2025 |
| Dorset Bathrooms and Kitchens Ltd | Construction | 2024 |
| Dorset Box Limited | Wholesale & retail | 2024 |
| Dorset Charcoal Co Ltd | Manufacturing | 2003 |
| Dorset Coppice Group Limited | Agriculture & fishing | 2003 |
| Dorset DIY Ltd | Extraterritorial | 2023 |
| Dorset Driving School Ltd | Education | 2023 |