| Dhriti Limited | Information & communication | 2019 |
| Diagne Shipment Ltd | Wholesale & retail | 2024 |
| Diamedia Plus Ltd | Health & social care | 2024 |
| Diamond Cars Oxford Ltd | Transport & logistics | 2024 |
| Diamond Estates & Homes Ltd | Real estate | 2020 |
| Diamond H20 Compliance Ltd | Water & waste | 2023 |
| Diamond Nails D&N Limited | Other services | 2025 |
| DIAMONDFLEX92 Limited | Manufacturing | 2018 |
| Diamondland Ltd | Wholesale & retail | 2021 |
| Diamondplus Care and Support Ltd | Public administration | 2025 |
| Diamondsure Limited | Administrative & support | 2019 |
| Diane Stevens Advanced Aesthetic Solutions Ltd | Other services | 2023 |
| Diane Wilding & Associates Limited | Professional & scientific | 1999 |
| Diaspora Housing Group Ltd | Real estate | 2025 |
| Dice Marine Ltd | Manufacturing | 2023 |
| Dicketts Development Consulting Limited | Professional & scientific | 2022 |
| Didcot LOW Carbon Hydrogen Limited | Administrative & support | 2022 |
| Diettree Ltd | Hospitality | 2020 |
| Difference Engine Ventures Limited | Financial services | 2023 |
| Different Duck Limited | Other services | 2018 |
| Dighton Developments Limited | Construction | 2012 |
| Dighton Lettings Limited | Administrative & support | 2018 |
| Digiecon Advisors Limited | Professional & scientific | 2013 |
| Digisell Ltd | Wholesale & retail | 2025 |
| Digital Business & Technology Partners Limited | Information & communication | 2013 |
| Digital Knowledge Ltd | Information & communication | 2012 |
| Digital Nest Limited | Information & communication | 2015 |
| Digital Remit Limited | Information & communication | 2013 |
| Digital Tax Records Limited | Professional & scientific | 2016 |
| Digital Veneer Limited | Information & communication | 2018 |
| Digitalfoundr Ltd | Education | 2022 |
| Digitizelectric Limited | Information & communication | 2016 |
| Digiverz Ltd | Information & communication | 2025 |
| Diligencia Consulting Limited | Information & communication | 2008 |
| Diligencia Group Limited | Financial services | 2023 |
| Diligent Agile Synthesis (DAS) Limited | Professional & scientific | 2017 |
| Dime Limited | Professional & scientific | 2007 |
| Dimensionworx Ltd | Health & social care | 2021 |
| Dimensionworx Properties Ltd | Real estate | 2023 |
| Diminas Ltd | Construction | 2025 |
| Dino Private Hire Limited | Transport & logistics | 2026 |
| Dinosaur TV and Video Limited | Information & communication | 2014 |
| Diocesan Trustees (Oxford) Limited | Other services | 1965 |
| Diomedon Ltd | Information & communication | 2025 |
| Dionach Ltd | Information & communication | 2000 |
| Diop Logistics 2025 Ltd | Transport & logistics | 2025 |
| DIP Sea Swimwear Ltd | Wholesale & retail | 2022 |
| Direct Construction (Oxford) Limited | | 1987 |
| Direct Publicity Limited | Administrative & support | 2003 |
| Disabled Countryside Access CIC | Health & social care | 2025 |
| Diseno Coffee Ltd | Hospitality | 2025 |
| Dishion Oxford Ltd | Hospitality | 2023 |
| Display-Fridge Wholesale Ltd. | Administrative & support | 2020 |
| Distant Object Productions Limited | Administrative & support | 2009 |
| Divergency Limited | Extraterritorial | 2005 |
| Diverse Thinking Limited | Professional & scientific | 2003 |
| Diversity Football League Ltd | Arts & recreation | 2018 |
| DIX Capital Partners Limited | Financial services | 2018 |
| DIX PIT Limited | Professional & scientific | 2005 |
| Dixon Holdings (Bishops Stortford) Limited | Financial services | 2023 |
| Dixon Holdings (Chichester) Limited | Financial services | 2023 |
| Dixon Holdings (Crawley) Limited | Financial services | 2023 |
| Dixon Holdings (Huntingdon) Limited | Financial services | 2024 |
| Dixon Holdings (Lawrence Baker) Limited | Financial services | 2024 |
| Dixon Holdings (ST Neots) Limited | Financial services | 2023 |
| Dixon Holdings (Stratford-Upon-Avon) Limited | Financial services | 2023 |
| Dixon Holdings (Uckfield) Limited | Financial services | 2023 |
| Dixon Holdings (Wichelstowe) Limited | Financial services | 2023 |
| Dixon Holdings Limited | Financial services | 2023 |
| Diya Developments Limited | Real estate | 2025 |
| Diya Enterprise Group Ltd | Wholesale & retail | 2025 |
| DJ Engineering Oxford Limited | Administrative & support | 2006 |
| DJG Wealth Planning Limited | Administrative & support | 2019 |
| DJM Solutions and Services Limited | Households | 2025 |
| DJO E-Commerce Ltd | Wholesale & retail | 2024 |
| DJS Antibodies Ltd | Professional & scientific | 2014 |
| DJT Business Solutions Ltd | Professional & scientific | 2024 |
| DJT Oxford Limited | Real estate | 2019 |
| DJW Contracting Limited | Agriculture & fishing | 2008 |
| DK BIO Ltd | Professional & scientific | 2025 |
| DK Landscaping Oxford Limited | Administrative & support | 2021 |
| DKM Developments Ltd | Real estate | 2024 |
| DKM Homes (Oxford) Ltd | Real estate | 2025 |
| Dkug Ltd | Administrative & support | 2022 |
| DM Car Wash Ltd | Administrative & support | 2019 |
| DM ED Solutions Ltd | Financial services | 2026 |
| Dmag Logistics Limited | Transport & logistics | 2025 |
| Dmcc Racing (UK) Limited | Arts & recreation | 2025 |
| DMR Technology Limited | Manufacturing | 2023 |
| DMU Catering UK Ltd | Hospitality | 2024 |
| DMU Construction Ltd | Construction | 2017 |
| DNA Boozers Ltd | Hospitality | 2025 |
| DNA Television Limited | Professional & scientific | 2007 |
| DNC Designs Ltd | Professional & scientific | 2024 |
| DND Investments Limited | Real estate | 2026 |
| Dnlms Limited | Professional & scientific | 1999 |
| Dnmx Limited | Professional & scientific | 2009 |
| DNS Building Ltd | Construction | 2024 |
| DO Nothing Books Limited | Information & communication | 2021 |
| Dobson & Young Ltd | Health & social care | 2025 |