| DG Developments (Dorset) Limited | Construction | 2014 |
| DG Plant Limited | Water & waste | 2026 |
| DH Building Services (Oxford) Limited | Construction | 2010 |
| DH Development Services Limited | Construction | 2021 |
| DH Plant Hire Ltd | Administrative & support | 2020 |
| Dhana Balaji Ltd | Hospitality | 2017 |
| DHE Design Ltd | Professional & scientific | 2019 |
| Dhph Oxfordshire Ltd | Construction | 2019 |
| DI Macdonald Limited | Education | 2025 |
| Dial-A-Van (Oxon) Limited | Transport & logistics | 2010 |
| DIG a Hole With ME Ltd | Construction | 2025 |
| Digital Dispatch (Intl) Ltd | Information & communication | 1981 |
| Digital JEM Ltd | Professional & scientific | 2016 |
| Digital PR Ltd | Professional & scientific | 2021 |
| Digitalphobia Ltd | Information & communication | 2016 |
| Dinton Homes Limited | Other services | 2024 |
| Discountpk Ltd | Wholesale & retail | 2026 |
| Discover Momenta Ltd | Health & social care | 2013 |
| Disk Archive Corporation Limited | Information & communication | 2011 |
| Diva Nails & Beauty Ltd | Other services | 2024 |
| Dixey Gerrans Ltd | Professional & scientific | 2019 |
| DJE Building Contractors Ltd | Professional & scientific | 2013 |
| DJF Properties and Lettings Ltd | Real estate | 2024 |
| Djliftstraining Ltd | Other services | 2022 |
| Dlamini &Cooper Limited | Health & social care | 2020 |
| Dlbb Developments Limited | Construction | 2010 |
| DLS Plastering Ltd | Construction | 2025 |
| Dlweston Ltd | Real estate | 2018 |
| DMC Build Ltd | Construction | 2022 |
| DNA Compliance Ltd | Professional & scientific | 2026 |
| DNA Safety Solutions Ltd | Professional & scientific | 2021 |
| DNS Property Holdings Limited | Real estate | 2017 |
| Domestic Appliance World Repairs Ltd | Other services | 2024 |
| Dominic Grace Ltd | Professional & scientific | 2020 |
| Don'T Break Character Ltd | Manufacturing | 2025 |
| Donaldson Timber Systems Limited | Manufacturing | 2016 |
| Donchimo Consultancy Ltd | Construction | 2020 |
| Dono Venator Limited | Extraterritorial | 2024 |
| Donson Consultancy Ltd | Construction | 2018 |
| Dorchester Assets Ltd | Administrative & support | 2024 |
| Dorchester Freehold Ltd | Financial services | 2020 |
| Dorchester Management Ltd | Real estate | 2015 |
| DOT to DOT Psychology Ltd | Education | 2025 |
| Dotcar Ltd | Transport & logistics | 2019 |
| Double Sky Ltd | Real estate | 2022 |
| Double-Jump Innovation Limited | Professional & scientific | 2025 |
| Dove Air Conditioning Services Ltd | Construction | 2011 |
| Dove Court Management Company Limited | Households | 1986 |
| Dovecote Place Management Company Limited | Households | 2017 |
| Down Land Traditional Meats Ltd | Wholesale & retail | 2021 |
| Dpel Limited | Professional & scientific | 2013 |
| DR BEE Ltd | Administrative & support | 2009 |
| DR C Wood Ltd | Health & social care | 2025 |
| DR Kerry Sissins Chiropractor Limited | Health & social care | 2008 |
| DR Michael Hickman Ltd | Health & social care | 2012 |
| DR. Colin Tidy Medico-Legal Limited | Professional & scientific | 2011 |
| DR. Schubert Ltd | Professional & scientific | 2018 |
| DR. Stuart Mckechnie Limited | Health & social care | 2017 |
| Dragonsoft Business Solutions Limited | Information & communication | 2020 |
| Drakers Property Limited | Construction | 2024 |
| Dreamoir Ltd | Wholesale & retail | 2024 |
| Drew Warren Building Contractors Limited | Construction | 2005 |
| Drewett Signs Limited | Manufacturing | 2003 |
| Drewtech Limited | Professional & scientific | 2016 |
| Drift Woodworking Ltd | Construction | 2025 |
| Drive by US Ltd | Administrative & support | 2025 |
| Drive Engagement Limited | Professional & scientific | 2017 |
| Drive on Go Ltd | Administrative & support | 2025 |
| DRM Management Services Limited | Real estate | 2014 |
| DRN Energy Solutions Ltd | Professional & scientific | 2024 |
| Droplume Ltd | Wholesale & retail | 2025 |
| Drummers Bar Ltd. | Hospitality | 2018 |
| DSA Accounting Ltd | Professional & scientific | 2022 |
| DSA Prospect Audit Limited | Professional & scientific | 2010 |
| DSA Prospect Limited | Professional & scientific | 2013 |
| Dsap Holdings Limited | Financial services | 2023 |
| DSC Fitness Ltd | Arts & recreation | 2023 |
| DSR Management Services Ltd | Professional & scientific | 2020 |
| DSR Residential (Leasehold) Ltd | Real estate | 2025 |
| DSR Residential Ltd | Real estate | 2024 |
| Dtac Holdings Ltd | Financial services | 2026 |
| Ducker & Young Scaffolding Limited | Construction | 2009 |
| Ducroz Ltd | Professional & scientific | 2014 |
| Dudley Court (Oxford) Management Limited | Households | 1972 |
| Duncan Crine Mediation Limited | Professional & scientific | 2022 |
| Dunne Demolition Limited | Construction | 2017 |
| Dunne Haulage & Plant Hire Limited | Water & waste | 2015 |
| Durga Ltd | Construction | 2023 |
| Durham Enterprises (Oxford) Limited | Real estate | 2018 |
| Dustscan Limited | Professional & scientific | 2004 |
| Dustscan Trustees Limited | Professional & scientific | 2018 |
| Duttons Building Management Company Limited | Households | 2018 |
| DWD Developments Limited | Wholesale & retail | 1986 |
| DY Access Solutions Limited | Construction | 2024 |
| Défi Consultancy Services Limited | Real estate | 2017 |
| D’Oilly Manor Construction Ltd | Construction | 2023 |
| E D Glass Limited | Manufacturing | 2008 |
| E Sherry Ltd | Health & social care | 2010 |
| E&O Aviation Limited | Transport & logistics | 2018 |
| E-Collaboration Limited | Information & communication | 2006 |