| Oxford Contemporary Music | Arts & recreation | 1996 |
| Oxford Contract Cleaning Ltd | Administrative & support | 2018 |
| Oxford Counselling Centre Limited | Other services | 2013 |
| Oxford Craft Beer Company Limited | Extraterritorial | 2014 |
| Oxford Creative Hub Ltd | Information & communication | 2018 |
| Oxford Cryotechnology Limited | Professional & scientific | 2023 |
| Oxford Curtains and Alterations Ltd | Manufacturing | 2024 |
| Oxford Dental & Aesthetics Limited | Health & social care | 2010 |
| Oxford Dermatology Limited | Health & social care | 2022 |
| Oxford Design Limited | Professional & scientific | 2002 |
| Oxford Development Solutions Ltd | Construction | 2020 |
| Oxford Devepopments Ltd | Construction | 2025 |
| Oxford Diagnostics Limited | Information & communication | 2009 |
| Oxford Digital Collective Limited | Information & communication | 2025 |
| Oxford Digital Education Academy Ltd | Education | 2015 |
| Oxford Digital Enterprises Limited | Information & communication | 1983 |
| Oxford Digital Learning Limited | Education | 2000 |
| Oxford Digital Marketing Limited | Information & communication | 2009 |
| Oxford Digital Media Limited | Information & communication | 2005 |
| Oxford Diocesan Board of Finance(The) | Other services | 1916 |
| Oxford Diocesan Bucks Schools Trust | Education | 2017 |
| Oxford Direct Services Limited | Administrative & support | 2017 |
| Oxford Direct Services Trading Limited | Water & waste | 2017 |
| Oxford Dive Centre (UK) Limited | Administrative & support | 2002 |
| Oxford Dogs Ltd | Hospitality | 2025 |
| Oxford Doko Fashion Limited | Wholesale & retail | 2025 |
| Oxford Driveways and Roofing Limited | Construction | 2024 |
| Oxford Driving School Limited | Other services | 2009 |
| Oxford Drug Design Limited | Professional & scientific | 2001 |
| Oxford Duplication Centre Limited | Manufacturing | 2013 |
| Oxford Dyslexia Consultancy Ltd | Professional & scientific | 2016 |
| Oxford Ebooks Limited | Information & communication | 2012 |
| Oxford Eco Houses Ltd | Construction | 2025 |
| Oxford Economic Consulting Ltd | Professional & scientific | 2025 |
| Oxford Economic Forecasting Limited | Information & communication | 1996 |
| Oxford Economics Group Limited | Professional & scientific | 2019 |
| Oxford Economics Limited | Professional & scientific | 1981 |
| Oxford Education and Service Ltd | Professional & scientific | 2008 |
| Oxford Educational Books Limited | Information & communication | 1984 |
| Oxford Educational Limited | Education | 1984 |
| Oxford Educational Partnership Limited | Education | 1999 |
| Oxford Educational Psychology Practice Ltd | Education | 2013 |
| Oxford Electrical Services Ltd | Construction | 2025 |
| Oxford Electrical Solutions Ltd | Construction | 2010 |
| Oxford Electronic Publishing Limited | Information & communication | 1984 |
| Oxford Empire Ventures Limited | Real estate | 2025 |
| Oxford Endeavours Limited | Professional & scientific | 2002 |
| Oxford Endovascular Limited | Professional & scientific | 2015 |
| Oxford Energy Intelligence Limited | Financial services | 2025 |
| Oxford Engineering Consultants Limited | Professional & scientific | 2023 |
| Oxford Engineering Design Limited | Professional & scientific | 2025 |
| Oxford Engineering Services Ltd | Information & communication | 2016 |
| Oxford English Football Limited | Education | 2019 |
| Oxford English Language Teaching Limited | Information & communication | 1984 |
| Oxford English Learning Limited | Information & communication | 1984 |
| Oxford English Limited | Information & communication | 1984 |
| Oxford English Teaching Limited | Information & communication | 1984 |
| Oxford Engtech Ltd | Professional & scientific | 1997 |
| Oxford ENT Ltd | Real estate | 2011 |
| Oxford Enterprise Ltd | Wholesale & retail | 2024 |
| Oxford Epidemiology Associates Limited | Professional & scientific | 2020 |
| Oxford ERP Services Ltd | Information & communication | 2017 |
| Oxford Esol Academy Ltd | Education | 2022 |
| Oxford Estates & Holdings Ltd | Real estate | 2024 |
| Oxford Event Hire Ltd | Administrative & support | 2005 |
| Oxford Evidentia Limited | Professional & scientific | 2009 |
| Oxford Excel College Limited | Education | 2013 |
| Oxford Executive Transfers Ltd | Transport & logistics | 2024 |
| Oxford Experience Limited | Wholesale & retail | 1987 |
| Oxford Expert Psychiatry Ltd | Health & social care | 2011 |
| Oxford Extensions Ltd | Construction | 2016 |
| Oxford Exterior Restoration Limited | Professional & scientific | 2024 |
| Oxford EYE Clinic Limited | Health & social care | 2022 |
| Oxford EYE Limited | Health & social care | 2022 |
| Oxford Facilities Management Ltd | Professional & scientific | 2024 |
| Oxford Fairings Limited | | 1975 |
| Oxford Fast Foods Limited | Hospitality | 2025 |
| Oxford Fertility Limited | Health & social care | 2004 |
| Oxford Fiber Ltd | Manufacturing | 2000 |
| Oxford Film and Video Makers Limited | Information & communication | 1986 |
| Oxford Film Festival Limited | Information & communication | 2016 |
| Oxford Film School Ltd | Education | 2016 |
| Oxford Finance Education Ltd | Education | 2021 |
| Oxford Finance Services Ltd | Administrative & support | 2017 |
| Oxford Finest Limited | Hospitality | 2019 |
| Oxford Finishing Touch Limited | Construction | 2026 |
| Oxford Fire Assessments Limited | Professional & scientific | 2018 |
| Oxford Floors and Tiles Ltd | Construction | 2017 |
| Oxford Football Partnership Limited | Arts & recreation | 2017 |
| Oxford Foundation for Neurorehabilitation Science (Oxfcns) Ltd | Professional & scientific | 2025 |
| Oxford Foundation for Theoretical Neuroscience and Artificial Intelligence | Professional & scientific | 2006 |
| Oxford Fresh Food Ltd | Wholesale & retail | 2021 |
| Oxford Fruits & VEG Ltd | Wholesale & retail | 2023 |
| Oxford FX Limited | Professional & scientific | 2012 |
| Oxford Garage and MOT Ltd | Wholesale & retail | 2022 |
| Oxford Garden Company Limited | Administrative & support | 2018 |
| Oxford GAS Services Limited | Administrative & support | 2007 |
| Oxford Gateway Limited | Extraterritorial | 2002 |
| Oxford Gifts & Souvenirs Limited | Wholesale & retail | 2013 |
| Oxford Glam Enterprises Limited | Administrative & support | 2025 |