| Oxfordshire Assessments Ltd | Construction | 2018 |
| Oxfordshire Auto's & Recovery Ltd | Wholesale & retail | 2019 |
| Oxfordshire Bookkeeping Ltd | Professional & scientific | 2023 |
| Oxfordshire Chainsaw Training Ltd | Education | 2024 |
| Oxfordshire Chauffeurs Oxford UK Ltd | Transport & logistics | 2019 |
| Oxfordshire Cleaning Company Ltd | Administrative & support | 2023 |
| Oxfordshire Drinks Ltd | Wholesale & retail | 2022 |
| Oxfordshire Electrical Services Limited | Construction | 2014 |
| Oxfordshire Fire and Security Services Ltd | Administrative & support | 2022 |
| Oxfordshire Fire Extinguishers Ltd | Public administration | 2022 |
| Oxfordshire Leaflet Ltd | Professional & scientific | 2019 |
| Oxfordshire Pilates Limited | Arts & recreation | 2014 |
| Oxfordshire Plastering Company Limited | Construction | 2022 |
| Oxfordshire Property Care Co Ltd | Construction | 2025 |
| Oxfordshire Security Ltd | Administrative & support | 2022 |
| Oxfordshire Security Services Ltd | Administrative & support | 2020 |
| Oxfordshire Throat Clinic Limited | Health & social care | 2026 |
| Oxfordshire Web Services Limited | Information & communication | 2013 |
| Oxfordshire WET Rooms & Showers Limited | Construction | 2014 |
| Oxfordtimberwindows Limited | Construction | 2012 |
| Oxheat Limited | Construction | 2024 |
| Oxis Media Limited | Professional & scientific | 2012 |
| Oxlets Limited | Real estate | 2009 |
| Oxmanor Properties Limited | Real estate | 2024 |
| Oxon Care Supplies Ltd | Wholesale & retail | 2024 |
| Oxon Classic Cars Ltd | Wholesale & retail | 2019 |
| Oxon Exterior Cleaning Limited | Administrative & support | 2026 |
| Oxon Holdings Limited | Financial services | 2025 |
| Oxon Modern House Ltd | Wholesale & retail | 2024 |
| Oxon Snacks Ltd | Extraterritorial | 2021 |
| Oxon Transport Services Limited | Transport & logistics | 2010 |
| Oxoniensis Limited | Professional & scientific | 2006 |
| OXP Limited | Manufacturing | 2003 |
| Oxpac-Oxon Ltd | Wholesale & retail | 2012 |
| Oxsecure Services Ltd | Administrative & support | 2008 |
| Oxwolds Ltd | Construction | 2023 |
| Oxygen Management Ltd | Construction | 2017 |
| Ozlantic Limited | Professional & scientific | 2014 |
| P & L Carpentry Limited | Construction | 2013 |
| P & R Daniel Ltd | Other services | 2010 |
| P and S Building Limited | Construction | 2021 |
| P Creed Investments Ltd | Financial services | 2026 |
| P Godfrey Landscaping & Fencing Limited | Administrative & support | 2007 |
| P J Hare (Osas) Limited | Manufacturing | 2021 |
| P J Martin Carpet Specialist Ltd | Other services | 2011 |
| P Mullins Lettings Ltd | Real estate | 2023 |
| P Whetton Plumbing and Heating Ltd | Construction | 2018 |
| P&D Group Gold Properties Limited | Real estate | 2021 |
| P-Cubed Solutions Ltd | Extraterritorial | 2023 |
| P. Bruno Car Repairs Limited | Wholesale & retail | 2023 |
| P. S. King & Co. (Finance) Limited | Real estate | 1959 |
| P.D. Buckingham Tipper Hire Limited | Transport & logistics | 2010 |
| P2PL Holdings Ltd | Financial services | 2025 |
| Paddy Labs (UK) Limited | Information & communication | 2024 |
| Padzzz Limited | Real estate | 2017 |
| PAF Poultry Consultancy Limited | Professional & scientific | 2014 |
| Paget Computing Consultants Limited | Manufacturing | 2022 |
| Pagetech Ltd | Information & communication | 2026 |
| Palace Cuisine Limited | Manufacturing | 2002 |
| Palmer Batting App Limited | Professional & scientific | 2023 |
| Paloma Solutions Limited | Professional & scientific | 2016 |
| Pams Holdings Limited | Real estate | 2018 |
| Panda Smith Limited | Other services | 2024 |
| Pandamonium Group Ltd | Financial services | 2026 |
| Pandemonium Software Ltd | Information & communication | 2026 |
| Pankas Foods Ltd | Hospitality | 2015 |
| Pant Y Maen Wind Limited | Energy | 2013 |
| Pantheon Finance Limited | Professional & scientific | 2017 |
| Papa Romeo Public Relations Ltd | Professional & scientific | 2013 |
| Paradise Windows (Lechlade) Limited | Construction | 2013 |
| Paragon Kitchen Catering Ltd | Hospitality | 2026 |
| Parakore Limited | Manufacturing | 2022 |
| Parasang Ltd | Financial services | 2023 |
| Parenting With Passion Ltd | Information & communication | 2017 |
| Park END Events Limited | Professional & scientific | 2022 |
| Park House Antiques Limited | Wholesale & retail | 2002 |
| Park Town Homes Ltd | Construction | 2019 |
| Park's Edge Developments Ltd | Construction | 2016 |
| Park's Edge Homes Ltd | Construction | 2022 |
| Parker-Jones Estates & Developments Ltd | Administrative & support | 2022 |
| Parkram Limited | | 1985 |
| Parktown Consulting Limited | Professional & scientific | 2013 |
| Parnham Estates Limited | Administrative & support | 2020 |
| Parnham House LLP | | 2020 |
| Parnham Interiors Limited | Extraterritorial | 2003 |
| Parrhesia Care Services Limited | Administrative & support | 2023 |
| Partial Software Ltd | Information & communication | 2021 |
| Passacaglia Consulting Limited | Professional & scientific | 2015 |
| Pattison Consulting Ltd | Professional & scientific | 2020 |
| Patton Limited | Real estate | 2022 |
| Paul Hopkins Ltd | Professional & scientific | 2018 |
| Paul Jordan Investments Limited | Real estate | 2016 |
| Paul Jordan Limited | Construction | 2012 |
| Paul Maltby Enterprises Ltd | Wholesale & retail | 2021 |
| Paws Wholesale Ltd | Wholesale & retail | 2023 |
| Paxford Engineering Limited | Manufacturing | 2008 |
| PB Industries Limited | Professional & scientific | 2026 |
| PC Scaffolding Limited | Construction | 2010 |
| PD AVC Limited | Extraterritorial | 2018 |
| PD4 Consulting Ltd | Information & communication | 2021 |