| Oxbrew Taproom Ltd | Hospitality | 2023 |
| Oxbridge Advisers Limited | Professional & scientific | 2023 |
| Oxbridge Business Consultants Ltd. | Professional & scientific | 2022 |
| Oxbridge Capital Property Ltd | Households | 2025 |
| Oxbridge College Limited | Education | 2011 |
| Oxbridge Design & Detailing Services Limited | Professional & scientific | 2005 |
| Oxbridge Exams Ltd | Health & social care | 2013 |
| Oxbridge Global Ltd | Professional & scientific | 2021 |
| Oxbridge Insight | | 2008 |
| Oxbyte Tech Limited | Professional & scientific | 2020 |
| OXC Scientific Limited | Professional & scientific | 2024 |
| Oxcam Properties Ltd | Real estate | 2025 |
| Oxcamb Limited | Professional & scientific | 2007 |
| Oxcarbon Limited | Professional & scientific | 2021 |
| Oxcare Ltd | Health & social care | 2017 |
| Oxccu Tech Ltd | Professional & scientific | 2021 |
| Oxcelerate Engineering Ltd | Professional & scientific | 2025 |
| Oxcell Ltd | Professional & scientific | 2021 |
| Oxcha Limited | Manufacturing | 2024 |
| Oxcis Limited | Real estate | 1998 |
| Oxcon Limited | Real estate | 1966 |
| Oxcontrols Ltd | Information & communication | 2015 |
| Oxcoproduction Ltd | Information & communication | 2022 |
| Oxdevs Ltd | Information & communication | 2026 |
| Oxed UK Trading Ltd | Education | 2020 |
| Oxenaforda Ltd | Real estate | 2017 |
| Oxenford Design Ltd | Construction | 2024 |
| Oxera Consulting (France) LLP | | 2018 |
| Oxera Consulting (Netherlands) LLP | | 2018 |
| Oxera Consulting LLP | | 2014 |
| Oxeyns Limited | Wholesale & retail | 2014 |
| OXF Properties Limited | Real estate | 2025 |
| Oxfam | Health & social care | 1958 |
| Oxfam Activities Limited | Water & waste | 1964 |
| Oxfam Advisory Service Limited | Financial services | 2012 |
| Oxfirst Ltd | Professional & scientific | 2011 |
| Oxfomatic Limited | Administrative & support | 2021 |
| Oxfood International Ltd | Wholesale & retail | 2017 |
| Oxford & Cambridge Education Programmes Ltd | Education | 2022 |
| Oxford & Co. Ltd. | Wholesale & retail | 2016 |
| Oxford & District Indoor Bowls Association Limited | Arts & recreation | 1972 |
| Oxford & Witney Factors (2018) Limited | Real estate | 2018 |
| Oxford (UK) Excellence Limited | Administrative & support | 2006 |
| Oxford 3D Printing Ltd | Manufacturing | 2026 |
| Oxford A.M Cleaning Services Limited | Administrative & support | 2014 |
| Oxford Abstracts Limited | Information & communication | 2001 |
| Oxford Academic Editing Ltd | Extraterritorial | 2021 |
| Oxford Academic Press Limited | Information & communication | 1984 |
| Oxford Academic Programmes Ltd | Education | 2015 |
| Oxford Academic Union Limited | Administrative & support | 2006 |
| Oxford Academy of Education and Cultural Studies Ltd | Information & communication | 2025 |
| Oxford Academy of English Ltd | Information & communication | 2023 |
| Oxford Academy of Management Ltd | Public administration | 1997 |
| Oxford Accelerator Limited | Professional & scientific | 2014 |
| Oxford Accommodation Ltd | Real estate | 2026 |
| Oxford Accountants for Business Ltd | Administrative & support | 2013 |
| Oxford Active Limited | Arts & recreation | 2003 |
| Oxford Advanced Research Centres Limited | Professional & scientific | 2017 |
| Oxford Advisory Group Ltd | Information & communication | 2024 |
| Oxford African Chopz and Food Limited | Hospitality | 2025 |
| Oxford Afrobeats Festival Ltd | Hospitality | 2023 |
| Oxford Aggregates Limited | Construction | 2018 |
| Oxford AI Systems Ltd | Information & communication | 2026 |
| Oxford Airport Transfers Ltd | Transport & logistics | 2025 |
| Oxford Anaesthetic Services Limited | Health & social care | 2009 |
| Oxford Analysis Limited | Information & communication | 2011 |
| Oxford and Bucks Oral Surgery Ltd | Health & social care | 2021 |
| Oxford and London Training Company Limited | Professional & scientific | 2014 |
| Oxford and Swindon Area Quaker Meeting of the Religious Society of Friends (Quakers) in Britain | Other services | 2009 |
| Oxford Antibiotics Limited | Extraterritorial | 2016 |
| Oxford Appliances Limited | Wholesale & retail | 2024 |
| Oxford Archaeology Limited | Professional & scientific | 1982 |
| Oxford Architects LLP | | 2006 |
| Oxford Art Society C.I.C. | Arts & recreation | 2021 |
| Oxford Arts CIC | Arts & recreation | 2016 |
| Oxford Asset Management LLP | | 2006 |
| Oxford Assets Limited | Professional & scientific | 2006 |
| Oxford Atelier Limited | Other services | 2017 |
| Oxford Athletic Football Club Limited | Arts & recreation | 2022 |
| Oxford Atlas Leisure Limited | Hospitality | 2011 |
| Oxford Audio Consultants Limited | Wholesale & retail | 1988 |
| Oxford Autos Ltd | Wholesale & retail | 2020 |
| Oxford Awards Agency Limited | Administrative & support | 2021 |
| Oxford Bakery and Cafe Limited | Manufacturing | 2014 |
| Oxford Beauty Limited | Other services | 2024 |
| Oxford Beauty Parlour Ltd | Other services | 2021 |
| Oxford Best-Tone Consult Ltd | Hospitality | 2012 |
| Oxford Bible Church Trust Limited | Financial services | 2011 |
| Oxford BIO Ventures Limited | Financial services | 2022 |
| Oxford Bioconcepts Ltd | Administrative & support | 2007 |
| Oxford Biodata Ltd | Information & communication | 2026 |
| Oxford Biodiscovery Limited | Education | 2024 |
| Oxford Biodynamics PLC | Manufacturing | 2007 |
| Oxford Biolabs Limited | Professional & scientific | 2009 |
| Oxford Biomaterials Holdings Limited | Professional & scientific | 2014 |
| Oxford Biomaterials Limited | Professional & scientific | 2001 |
| Oxford Biomedica (UK) Limited | Professional & scientific | 1995 |
| Oxford Biomedica PLC | Professional & scientific | 1996 |
| Oxford Biomedical College Ltd | Education | 2025 |
| Oxford Biosciences Ltd | Information & communication | 2013 |