| Dogs Walk This Way Rescue CIC | Bagshot | 2021 |
| Dogsden Day Care Ltd | Merthyr Tydfil | 2020 |
| Dogsplash&Play Ltd | Enfield | 2025 |
| Dogtastic Doggy Daycare Ltd | Coalville | 2023 |
| Dogtastic Grooming Ltd | Rosewell | 2021 |
| Dogtastic Playcare Ltd | Rosewell | 2023 |
| Dogwood Services Limited | Haywards Heath | 2015 |
| Doherty Bros Limited | Ballymena | 2013 |
| Doherty Harvesting Ltd. | Omagh | 2006 |
| Dokta Herbal Ltd | London | 2025 |
| Dolan Fisheries Ltd | Dingwall | 2015 |
| Dolau Farm Limited | Carlisle | 2020 |
| Dolau Ltd | Llandeilo | 2011 |
| Doles Farm Ltd | Wokingham | 2020 |
| Dolgan Limited | Armagh | 1996 |
| Dolgaran Vineyard Ltd | Llandysul | 2025 |
| Dolgarreg Farm Ltd | Carmarthen | 2025 |
| Dolgellau Allotment Community CIC | Dolgellau | 2023 |
| Dolidre Farms Ltd | Leominster | 2025 |
| Dolipas Farms Limited | Derry | 2011 |
| Dolittle Farm Ltd | Dover | 2023 |
| Dolly Mill Fisheries Ltd | Sheffield | 2019 |
| Dolly's Farm Ltd | Downpatrick | 2020 |
| Dolly's Yard Limited | Lisburn | 2012 |
| Dolmen Farm Limited | Castlewellan | 2010 |
| Doloi Tea Company Limited | Cupar | 1884 |
| Dolphenby Farming Ltd | Carlisle | 2023 |
| Dolphin Farms Limited | Salisbury | 1972 |
| Dolphinston Limited | Scotland | 2013 |
| Dolwen Farms Ltd | Welshpool | 2008 |
| Dolwen Fawr Farms Ltd | Carmarthenshire | 2015 |
| Doma (NI) Limited | Newcastle | 2014 |
| Domaine of the Rose and Bear Ltd | London | 2025 |
| Domaines Bournet-Lapostolle UK Limited | Godalming | 2022 |
| Domesticated K-9'S Ltd | Cranleigh | 2021 |
| Dominic Harrington Nurseries Limited | Wisbech | 2002 |
| Domon Ltd | Fetcham | 2023 |
| Domus Botanica Ltd | Glasgow | 2022 |
| DON Agri Services Limited | Tayside | 2006 |
| DON Catchment Rivers Trust | Driffield | 2008 |
| DON Green (Farms) Ltd. | York | 1992 |
| DON Plant Limited | Renfrewshire | 1972 |
| DON Valley Limited | Inverurie | 2004 |
| DON Van Meat Limited | Aberdeen | 2025 |
| Don'T Buy, Adopt Ltd | Northampton | 2022 |
| Don'T Throw in the Trowel! Ltd | Bolton | 2023 |
| Donal Bingham T/A Active Tree Care Limited | Taunton | 2017 |
| Donald Baron Limited | Herts | 1939 |
| Donald Byford Limited | Leicester | 1973 |
| Donald Dunbar Limited | | 2002 |
| Donald Farms Limited | Aberdeen | 1997 |
| Donald Ferguson & SON Limited | Essex | 1980 |
| Donald Galt Bloodstock Ltd | Banbury | 2023 |
| Donald Maclarty Limited | Ross-Shire | 2006 |
| Donald Moodie Fishing Ltd. | Livingston | 2003 |
| Donald Morrison Marine Services Ltd | Tain | 2022 |
| Donald Nicol (Farriers) Limited | Aberdeen | 2003 |
| Donald PIG & Poultry Ltd | Northallerton | 2012 |
| Donald Racey & Sons Limited | Cambridgeshire | 1976 |
| Donald Shanks Contractors Limited | Lairg | 2019 |
| Donaldson Livestock Limited | Okehampton | 2017 |
| Donaldson's Dairy Limited | Cleator Moor | 2017 |
| Donard View Farms Ltd | Downpatrick | 2011 |
| Doncaster Farm Limited | Newark | 1997 |
| Doncaster Fishing Centre Limited | South Yorkshire | 2006 |
| Dondelion Ltd | London | 2024 |
| Done & Go Services Ltd | Walthamstow | 2024 |
| Done & Hampson Limited | Wrexham | 2025 |
| Donegal Rapeseed Company Limited | 50 Campsie Road | 2009 |
| Doner Maker Limited | Milton Keynes | 2019 |
| Dongassi Ltd | Cambridge | 2024 |
| Dongbeinianyumi Ltd | Cardiff | 2021 |
| Dongpo Capital (UK) Limited | Aldermaston | 2016 |
| Donington CFC Limited | Donington Spalding | 2002 |
| Donington Housing Development Ltd | Boston | 2015 |
| Donkey Firewood Ltd | Walkerburn | 2023 |
| Donkeys Grazing Co Ltd | Clitheroe | 2009 |
| Donkeywell Farm Limited | Cirencester | 2025 |
| Donkleywood Farm Limited | Hexham | 2008 |
| Donlynx Cattery Limited | Bradford | 2021 |
| Donmac Farms Ltd | Cookstown | 2002 |
| Donnas Doggy Hotel Limited | Mansfield | 2025 |
| Donnelly Farms (NI) Ltd | Dungannon | 2015 |
| Donnewell Farm Limited | Stockton On Tees | 2025 |
| Donny KOI Ltd | Doncaster | 2023 |
| Donside Native Hedging Ltd | Inverurie | 2024 |
| Donto Marine Limited | Paignton | 2017 |
| Doon Valley Carp Ltd | Glasgow | 2025 |
| Doon-By Ltd. | Shetland | 2011 |
| Doonan Farms Ltd | Enniskillen | 2014 |
| Doonby Shorey Ltd | Fraserburgh | 2025 |
| Dooneen Farms Ltd | Islandmagee | 2014 |
| Door 343 Limited | Shetland | 2014 |
| Doorat Farms Limited | Strabane | 2022 |
| Doorstep Blooms Ltd | Bourne End | 2016 |
| DORACK9SERVICES Ltd | Bolton | 2025 |
| Doran Farming Ltd | Aughnacloy | 2019 |
| Doras Explorers Ltd | Chester Le Street | 2023 |
| Doraville Farms Limited | Luton | 2017 |
| Dorchester Meat Company Limited | Sturminster Newton | 1971 |