| Clearly Digital Limited | Wholesale & retail | 2003 |
| Clearstone Solutions Limited | Administrative & support | 2009 |
| Cliffside Management (Canford Cliffs) Limited | Extraterritorial | 2000 |
| Cloud Nine Florist Limited | Wholesale & retail | 2003 |
| Coade Ltd | Arts & recreation | 1999 |
| Coast Geoscience Limited | Professional & scientific | 2009 |
| Coastal Accounting Limited | Professional & scientific | 2000 |
| Coastal Industrial Services Ltd. | Construction | 2005 |
| Cobra Marketing Limited | Professional & scientific | 2005 |
| Cocoa Media Ltd | Professional & scientific | 2007 |
| Coda Music and Arts Trust Ltd | Education | 1997 |
| Cokers Frome Farm Limited | Agriculture & fishing | 1972 |
| Cole's Properties (Poole) Limited | Real estate | 1916 |
| Coles Miller (Secretaries) Limited | Professional & scientific | 1993 |
| Coles Miller Solicitors LLP | | 2006 |
| Combat Outlet Limited | Wholesale & retail | 2021 |
| Commercial Components (Portsmouth) Limited | Wholesale & retail | 2002 |
| Commercial Components Limited | Wholesale & retail | 1977 |
| Compliance Development Ltd | Professional & scientific | 2002 |
| Conceptualize Limited | Professional & scientific | 2003 |
| Coneygar Maritime & Offshore Services Limited | Professional & scientific | 2004 |
| Contact (People and Performance) Limited | Professional & scientific | 1999 |
| Contemporary Finishes Limited | Construction | 2007 |
| Corbar Consultants Limited | Extraterritorial | 2007 |
| Corfe Development International Ltd | Construction | 2019 |
| Cosmetic Warriors Limited | Professional & scientific | 2001 |
| Cosmetics to Go Limited | Professional & scientific | 2002 |
| Cote-Mer Management Ltd | Households | 2021 |
| Coulton Instrumentation Limited | Administrative & support | 2001 |
| County Shoes Limited | Wholesale & retail | 2005 |
| Coverworld Construction Limited | Administrative & support | 2000 |
| Craftipanda Ltd | Wholesale & retail | 2025 |
| Cream Court Limited | Professional & scientific | 1993 |
| Cresta Leisure Limited | Construction | 1987 |
| Cricket Chambers Management Company Limited | Households | 1997 |
| Crocker Farms Limited | Agriculture & fishing | 1998 |
| Croft Estate Facilities Limited | Administrative & support | 2004 |
| Crofton Court Maintenance Company Limited | Households | 1973 |
| Crusherform Grinding & Engineering Ltd | Manufacturing | 2006 |
| Crystalbond Limited | Real estate | 1997 |
| Current Electrical Limited | Construction | 1996 |
| Curzon Court (Bournemouth) Limited | Households | 1960 |
| Custom Carpentry Contractors Limited | Construction | 2006 |
| Cutting Edge Stuff Limited | Wholesale & retail | 2016 |
| Cyberwise Consulting Ltd | Information & communication | 2017 |
| Cygnus Instruments Limited | Manufacturing | 1983 |
| D K Marine Ltd | Transport & logistics | 2024 |
| D. & R. James Engineering Services Limited | Manufacturing | 1997 |
| D. Gimson & SON Roofing Contractors Limited | Construction | 2005 |
| D. P. Repairs Ltd | Wholesale & retail | 2003 |
| D.A. Cowburn Limited | Construction | 2002 |
| D.F.G. Knight & Sons Ltd | Construction | 2002 |
| D.J.Dampney (Cranborne) Limited | Agriculture & fishing | 1955 |
| D.K.B. Leasing Limited | Hospitality | 1989 |
| DAB Roofing & Leadworks Ltd | Construction | 2026 |
| DAE Construction Limited | Administrative & support | 2005 |
| Dairy Electrical Refrigeration Limited | Agriculture & fishing | 2003 |
| Dalehouse Limited | Hospitality | 2003 |
| Dalemain Engineering Limited | Professional & scientific | 1988 |
| Dalgleish Images Limited | Information & communication | 2003 |
| Damp HQ Ltd | Construction | 2024 |
| Dancing Rooster Christchurch Ltd | Hospitality | 2023 |
| Darren West Limited | Information & communication | 2007 |
| Datawave Computer Systems Limited | Information & communication | 1994 |
| Dave's Photography Limited | Professional & scientific | 2005 |
| David Graham Consultants Ltd | Construction | 2009 |
| David R White Building Services Limited | Construction | 2001 |
| David Restorick Interiors Limited | Construction | 2002 |
| David the Jeweller Limited | Wholesale & retail | 2005 |
| David Wren Limited | Professional & scientific | 2002 |
| Davis for Building Limited | Construction | 1997 |
| Davron Decor Ltd | Construction | 2007 |
| Dawsal Developments Ltd | Construction | 2006 |
| Daysons Limited | Construction | 2006 |
| DC Planning Ltd | Construction | 2004 |
| Defencell Limited | Administrative & support | 2006 |
| Delamare Publishing Limited | | 1978 |
| Delta Tango Enterprise Limited | Information & communication | 2007 |
| Desicon International Limited | | 1980 |
| Destiny Life Church Ltd | Other services | 2005 |
| Dexters Freehold Limited | Households | 2007 |
| Dextra Group PLC | Manufacturing | 1978 |
| Diamond Cart Ltd | Wholesale & retail | 2025 |
| Dibbsy UK Limited | Wholesale & retail | 2007 |
| Digital Design & Media Ltd | Information & communication | 2007 |
| Dike & SON Limited | Wholesale & retail | 1933 |
| Direct Hotels Limited | Hospitality | 2000 |
| Discover Events Ltd | Professional & scientific | 2024 |
| Diskovery Associates Limited | Information & communication | 2005 |
| Diverse UK Limited | Wholesale & retail | 2002 |
| Dixon Mechanical Services Limited | Construction | 2007 |
| Doc's Fitted Furniture Limited | Manufacturing | 2005 |
| Docmate Ltd | Information & communication | 2025 |
| Doctor and Doctors Limited | Health & social care | 2007 |
| Dorchester House Properties Limited | Other services | 2006 |
| Dorchester Motor Company Limited | Wholesale & retail | 1997 |
| Dorchester Timber Limited | Wholesale & retail | 2003 |
| Dorchester Typesetting Group Limited | Manufacturing | 1980 |
| Dorset Blue Soup Ltd | Manufacturing | 2022 |
| Dorset Door Fitters Limited | Construction | 2025 |