| Dockerill Groundworks Ltd | Construction | 2008 |
| Docky Barn Ltd | Hospitality | 2021 |
| Docme Technologies Ltd | Professional & scientific | 2021 |
| Docshop Ltd | Health & social care | 2023 |
| Doctor Rong Chinese Medicine & Acupuncture Ltd | Health & social care | 2023 |
| Doctors Laing Limited | Health & social care | 2023 |
| Doctors Migration Limited | Administrative & support | 2019 |
| Doctors With Africa Cuamm UK | Health & social care | 2017 |
| Documents & Analysis Publishing Limited | Information & communication | 1999 |
| Dodollar Products Limited | Extraterritorial | 2023 |
| Doka & Lenyo Composite Ltd | Manufacturing | 2023 |
| Doka Prepreg Composite Ltd | Manufacturing | 2023 |
| Doksac Ltd | Manufacturing | 2024 |
| Doliba Design Ltd | Professional & scientific | 2016 |
| Dolly's Clubhouse and Studio Limited | Real estate | 2025 |
| Dolphin Cleaning Management Ltd | Administrative & support | 2016 |
| Dolphin Computing (Cambridge) Ltd | Information & communication | 1994 |
| Dolphitech Ltd | Wholesale & retail | 2021 |
| Dolster Ltd | Financial services | 2019 |
| DOM Ventures Limited | Professional & scientific | 2018 |
| Domijia Co., Ltd | Wholesale & retail | 2025 |
| Dominik Composite Ltd | Manufacturing | 2024 |
| Dominion Care Cornwall Limited | Health & social care | 2022 |
| Dominique Brava Limited | Financial services | 2017 |
| Domino Printing Sciences Public Limited Company | Manufacturing | 1978 |
| Domino UK Limited | Manufacturing | 1983 |
| Domo Industry Co., Ltd | Wholesale & retail | 2016 |
| Domus Cantab Limited | Real estate | 2017 |
| Domus Property Holdings Ltd | Real estate | 2020 |
| Domuum Imperium Ltd | Real estate | 2025 |
| Don'T Blame ME Ltd | Arts & recreation | 2024 |
| Dona HAJ Limited | Professional & scientific | 2016 |
| Dona Hangers Ltd | Manufacturing | 2018 |
| Dongassi Ltd | Agriculture & fishing | 2024 |
| Donge Productions Ltd | Financial services | 2025 |
| Dongfang Celain Co., Ltd | Extraterritorial | 2014 |
| Dongfang Import and Export Co., Limited | Manufacturing | 2017 |
| Dongfanghong Trading Co., Ltd | Wholesale & retail | 2023 |
| Dongfeng International Trading Ltd | Wholesale & retail | 2024 |
| Dongguan Edisoneden Gift Co., Ltd | Extraterritorial | 2014 |
| Dongguan Liming Wool Weaving Co., Ltd. | Manufacturing | 2025 |
| Dongguan SYX DIE Casting Tech Co., Ltd | Extraterritorial | 2021 |
| Donghi Ltd | Manufacturing | 2023 |
| Dongkuan Import and Export Co., Ltd | Extraterritorial | 2018 |
| Dongyang Fengye Imp&Exp Co., Ltd | Manufacturing | 2018 |
| Dongyang Jiapeng Import and Export Co., Ltd | Administrative & support | 2021 |
| Donnington NO. 1 Management Limited | Households | 2019 |
| Donovan Medical Services Ltd | Health & social care | 2021 |
| Doodle Video Limited | Information & communication | 2013 |
| Doodlehouses Limited | Manufacturing | 2009 |
| Doorsafe Entry Systems Limited | Construction | 2019 |
| Dora Medica Ltd | Health & social care | 2022 |
| Dorcas Health and Care Ltd | Health & social care | 2023 |
| Dorel Sheet Metal Limited | Manufacturing | 2024 |
| Dorinel Constructions Limited | Other services | 2019 |
| Dormy House Management Company Limited (the) | Households | 1963 |
| Doru Baboi Ltd | Manufacturing | 2024 |
| Doruke Co. Ltd | Manufacturing | 2024 |
| Dorutzxu Ltd | Manufacturing | 2025 |
| Dossorola Tranding Co., Ltd | Wholesale & retail | 2023 |
| DOT Rouge Limited | Professional & scientific | 2004 |
| Dotcom Energy Ltd | Manufacturing | 2020 |
| Dotcom Foods Ltd | Wholesale & retail | 2020 |
| Dotcx Consulting Limited | Information & communication | 2013 |
| Dotothepowertwo Ltd | Professional & scientific | 2022 |
| Dotspace Ltd | Wholesale & retail | 2023 |
| Dotted Dream Ltd | Information & communication | 2020 |
| Double H Management Limited | Real estate | 2019 |
| Double O Safety Consulting Ltd | Professional & scientific | 2023 |
| Double Seven Consulting Ltd | Professional & scientific | 2025 |
| Double Success Limited | Wholesale & retail | 2017 |
| Double Take Ltd | Information & communication | 2026 |
| Double Z Fashion Trading Ltd | Wholesale & retail | 2025 |
| Doublelimit-Tooling Industrial Co., Ltd | Extraterritorial | 2013 |
| Doublescience Ltd | Other services | 2020 |
| Doublewoods Consultants Limited | Information & communication | 2015 |
| Douce Clothing Limited | Wholesale & retail | 2019 |
| Douce Heights Ltd | Hospitality | 2024 |
| Douce Ltd. | Other services | 2015 |
| Doug Williamson Ltd | Education | 2008 |
| Douglas Lodge Investments Ltd | Hospitality | 2021 |
| Douglas Oakervee Consulting Engineers Ltd | Professional & scientific | 2009 |
| Douglas Turner Clinical Group Limited | Health & social care | 2022 |
| Douglas Weston Tradehouse Limited | Professional & scientific | 2016 |
| Douglass Digital Limited | Information & communication | 2014 |
| Dovecote Cellar Limited | Wholesale & retail | 2024 |
| Dovers Farm Estates Limited | Real estate | 1937 |
| Dovetailer Trade Limited | Wholesale & retail | 2025 |
| DOW Dupont (Holland) Agrochemical Products Co., Ltd | Wholesale & retail | 2023 |
| Dowling Energy Limited | Professional & scientific | 2023 |
| Downing College (Regent Street) Limited | Real estate | 2001 |
| Downing Court Estate Management Limited | Other services | 2004 |
| Downing Wealth Management Ltd | Financial services | 2018 |
| Downton Kimberley Import & Export Limited | Wholesale & retail | 2021 |
| Doxa Labs Ltd | Information & communication | 2019 |
| DP Financial Solutions Ltd | Financial services | 2018 |
| DP Industry Co., Ltd | Wholesale & retail | 2025 |
| Dpwr Consulting Ltd | Professional & scientific | 2018 |
| DR a Sardesai Ltd | Health & social care | 2016 |
| DR a Sehgal Limited | Professional & scientific | 2013 |