| Day and Nightcare Live in Limited | Administrative & support | 2008 |
| Day Mart Ltd | Wholesale & retail | 2021 |
| Daybreak Oxford | Health & social care | 2005 |
| Dayonehr Limited | Administrative & support | 2017 |
| Dayyan Ltd | Wholesale & retail | 2016 |
| Dazley Brickwork Ltd | Construction | 2020 |
| DB Environmental Management Services Limited | Professional & scientific | 2013 |
| DBH & Co. Ltd | Real estate | 2025 |
| DC Consulting (Oxford) Limited | Construction | 2021 |
| DC Europe Ltd | Information & communication | 2020 |
| Dcme Ltd | Information & communication | 2022 |
| DDB Appliances Ltd | Other services | 2022 |
| DDL Building Services Ltd | Construction | 2025 |
| DE Property Group Limited | Real estate | 2018 |
| Deacon Management Consultancy Limited | Information & communication | 2007 |
| Deakin Limited | Professional & scientific | 2025 |
| Dean Court Community Association | Real estate | 2012 |
| Dean House Limited | Households | 2021 |
| Deathblo Ltd. | Professional & scientific | 2012 |
| Debate Chamber Limited | Other services | 2004 |
| Debbie K Therapy Ltd | Health & social care | 2025 |
| Debbie's Beauty Ltd | Other services | 2026 |
| Debohun Ltd | Construction | 2012 |
| Debt Recoveries (Oxfordshire) Limited | Administrative & support | 2016 |
| Decadent Times CIC | Arts & recreation | 2021 |
| DECIMA2 Ltd | Information & communication | 2023 |
| Decisionsoft Limited | Extraterritorial | 2009 |
| Decisive Ltd | Professional & scientific | 2023 |
| Deckhive Ltd | Information & communication | 2020 |
| Decnuk Limited | Wholesale & retail | 2022 |
| Deedit Ltd | Information & communication | 2024 |
| Deekriyo Limited | Administrative & support | 2013 |
| Deep Cover Limited | Arts & recreation | 2016 |
| Deep END Records Limited | Arts & recreation | 2018 |
| Deep Origin Ltd | Information & communication | 2023 |
| Deep Sand Skin Limited | Manufacturing | 2023 |
| Deep Vision Consultants Limited | Information & communication | 2019 |
| Deeper Learning Limited | Professional & scientific | 2013 |
| Deepsense Robotics Limited | Information & communication | 2022 |
| Definitive Applications Limited | Information & communication | 1988 |
| Deft Engineering Solutions Ltd | Professional & scientific | 2018 |
| Deja-Ville Room Lets Ltd. | Real estate | 2019 |
| Delana Ltd | Wholesale & retail | 2024 |
| Delavalle Ltd | Manufacturing | 2020 |
| Deliberai Ltd | Information & communication | 2026 |
| Delight's Kitchen and Bar Ltd | Construction | 2021 |
| Delise Aesthetics Ltd | Other services | 2021 |
| Delity Accountants Limited | Professional & scientific | 2024 |
| Delti Limited | Information & communication | 2020 |
| Demaine Media Limited | Arts & recreation | 2011 |
| Dempsey Property Investments Limited | Real estate | 2023 |
| DEN Boer Properties Ltd | Real estate | 2022 |
| Denefield Homes Ltd | Construction | 2018 |
| Denise Brown Limited | Wholesale & retail | 2001 |
| Dentactics Dental Staff Agency Ltd | Administrative & support | 2021 |
| Dentbooks Limited | Professional & scientific | 2026 |
| Dentify Education Limited | Education | 2019 |
| Denton House Management Company Limited | Households | 1995 |
| Dequorum Technologies Ltd | Information & communication | 2026 |
| Dermalere Skincare Ltd | Wholesale & retail | 2025 |
| Dermex Group Limited | Health & social care | 2017 |
| Dero MN Limited | Transport & logistics | 2025 |
| Derril Developments Limited | Real estate | 2022 |
| Design and Build Oxford Ltd | Construction | 2014 |
| Design Fusion Limited | Extraterritorial | 2001 |
| Design House Oxford Ltd | Real estate | 2018 |
| Design Storey Limited | Construction | 2013 |
| Designer Carbon Materials Limited | Manufacturing | 2014 |
| Designer Food Creations Ltd | Other services | 2019 |
| Designink Oxford Limited | Professional & scientific | 2014 |
| Designity Ltd | Professional & scientific | 2023 |
| Designsbygomes Ltd | Information & communication | 2024 |
| Designthought Ventures Ltd | Professional & scientific | 2024 |
| Designxdm Ltd | Information & communication | 2025 |
| Deson Fire Doors Ltd | Wholesale & retail | 2018 |
| Deson Holdings Ltd | Financial services | 2018 |
| Deson Project Management Consultancy Ltd | Construction | 2018 |
| Deson Property Ltd | Real estate | 2018 |
| Destimada Limited | Professional & scientific | 2023 |
| Destiny Atelier Limited | Manufacturing | 2026 |
| Destiny Groceries Ltd | Wholesale & retail | 2021 |
| Deutsche Samstagsschule North Oxford CIC | Education | 2021 |
| Deva Health Care Services Limited | Health & social care | 2018 |
| Deva Victrix Enterprises Ltd | Education | 2022 |
| Development Analytics Ltd | Professional & scientific | 2014 |
| Development Partners UK Ltd | Professional & scientific | 1999 |
| Deviation Events Limited | Arts & recreation | 2024 |
| Devils in the Detail Limited | Wholesale & retail | 2012 |
| Devine Insulation Limited | Construction | 1997 |
| Devryn Software Engineering Limited | Professional & scientific | 1994 |
| Dewvanie Training Limited | Professional & scientific | 2001 |
| DF Leadwork Limited | Construction | 2004 |
| DF Williams Holding Limited | Financial services | 2020 |
| DG & JG Accountancy Services Limited | Professional & scientific | 2011 |
| Dgnm Group Ltd | Construction | 2019 |
| DGS Carpentry Limited | Manufacturing | 2024 |
| DGS Pharmaceutical Consultancy Ltd | Professional & scientific | 2013 |
| DH Oxford Ltd | Administrative & support | 2025 |
| DH Roofing Solutions Ltd | Construction | 2025 |
| Dhara PVT Ltd | Wholesale & retail | 2026 |