| Oxlivia Ltd | Wholesale & retail | 2025 |
| Oxon Accountancy Ltd | Professional & scientific | 2012 |
| Oxon Accounting Ltd | Professional & scientific | 2006 |
| Oxon Car Centre Limited | Wholesale & retail | 2019 |
| Oxon Oven Cleaning Limited | Administrative & support | 2024 |
| Oxonclean Ltd | Administrative & support | 2025 |
| Oxpath Limited | Health & social care | 2020 |
| Oxtrades Directory Ltd | Information & communication | 2025 |
| OXV Holding Co Ltd | Wholesale & retail | 2013 |
| Oxygen Investments Ltd | Financial services | 2020 |
| Oxygen Lets Ltd | Real estate | 2019 |
| Ozcan Cinar Ltd | Wholesale & retail | 2025 |
| OZN Digital Ltd | Wholesale & retail | 2025 |
| P & M Facilities Limited | Construction | 2018 |
| P C Painter & Decorator Limited | Construction | 2017 |
| P R Whittington Ltd | Administrative & support | 2003 |
| P&C Milestone Developments Limited | Construction | 2026 |
| P&N Cleaning Limited | Administrative & support | 2023 |
| P. Sharp Holdings Limited | Financial services | 2026 |
| P.C. Support Centre Limited | Information & communication | 1998 |
| P.O.Dunbar and Company Limited | Real estate | 1963 |
| P2I Holdings Ltd | Financial services | 2025 |
| P2I Ltd | Manufacturing | 2003 |
| Pacer Hub Limited | Administrative & support | 2025 |
| Pacewell Developers Ltd | Construction | 2012 |
| Padworth Estates Limited | Financial services | 1945 |
| Paijh LLP | | 2025 |
| Palcon Engineering Services Limited | Construction | 2020 |
| Pallant Orthodontics Ltd | Health & social care | 2021 |
| Pandaville Ltd | Administrative & support | 2024 |
| Panther Business IT Services Ltd | Information & communication | 2016 |
| Panzo Ltd | Manufacturing | 2008 |
| Papyon Media Ltd | Wholesale & retail | 2026 |
| Parachute Solutions Ltd | Professional & scientific | 2024 |
| Parity Productions Limited | Information & communication | 2021 |
| Park Court Management (Didcot) Limited | Real estate | 1980 |
| Park Farm (Oxford) Limited | Agriculture & fishing | 2021 |
| Parklaine Ltd | Construction | 2020 |
| Parklands Manor Oxfordshire Limited | Households | 2025 |
| Parsons Close Stables Ltd | Agriculture & fishing | 2023 |
| Parsons Mead (Abingdon) Management Company Limited | Administrative & support | 2000 |
| Partner Commercial Finance Limited | Administrative & support | 2005 |
| Party Carter Limited | Arts & recreation | 2021 |
| PAT Dobbs Limited | Arts & recreation | 2010 |
| Path & Pace Ltd | Professional & scientific | 2026 |
| Pathios Therapeutics Limited | Professional & scientific | 2017 |
| Patina Classics Ltd | Wholesale & retail | 2018 |
| Paton Land Ltd | Real estate | 2023 |
| PATON5 Limited | Real estate | 2023 |
| Paul Butt Planning Limited | Professional & scientific | 2012 |
| Paul Byles Wealth Management Limited | Financial services | 2010 |
| Paul Franklin Construction Limited | | 1993 |
| Paul Mason Consulting Limited | Information & communication | 2001 |
| Paul O'Brien Racing Limited | Arts & recreation | 2023 |
| Paul Pounds Glazing Limited | Construction | 2021 |
| Paul Sutton Ltd | Information & communication | 2014 |
| Paws Galore Pet Sitters Limited | Households | 2015 |
| Pawsandplayatwillows Limited | Hospitality | 2024 |
| Paylode Limited | Professional & scientific | 2025 |
| PCC Technical Solutions Limited | Professional & scientific | 2015 |
| Peachcroft House Limited | Hospitality | 2025 |
| Pedal Power (Abingdon) Limited | Wholesale & retail | 2008 |
| Pendon Museum Sales Limited | Wholesale & retail | 1976 |
| Pendon Museum Trust Limited(The) | Arts & recreation | 1961 |
| Penlon Limited | Manufacturing | 1996 |
| People Shop Ltd | Information & communication | 2006 |
| Pepperfry Ltd | Administrative & support | 2017 |
| Pera Holdings Limited | Financial services | 2008 |
| Perah Limited | Information & communication | 2018 |
| Pereira Casey Enterprise Limited | Real estate | 2005 |
| Perfect Buid Ltd | Construction | 2022 |
| Perfect Party Packages Ltd | Education | 2024 |
| Perry Group Limited | Construction | 2016 |
| Peter Kemp Ltd | Professional & scientific | 2009 |
| Peter L Mansbridge & SON Limited | Construction | 2004 |
| Peter Sumner Consulting Ltd | Professional & scientific | 2017 |
| Peter the Heater Limited | Manufacturing | 2008 |
| Petroplas Limited | Extraterritorial | 1986 |
| Pettet Composites Ltd | Manufacturing | 2024 |
| Pewsey Oral Care Services Ltd | Health & social care | 2022 |
| Pfbc Limited | Professional & scientific | 2019 |
| PG Surveying Limited | Professional & scientific | 2020 |
| Pharmaprice International Limited | Professional & scientific | 2004 |
| Philomena MYD Properties Ltd | Real estate | 2024 |
| Phoebe AI Limited | Hospitality | 2020 |
| Phorensis Ltd | Professional & scientific | 2019 |
| Phymacs Tutoring Ltd | Professional & scientific | 2016 |
| Physiomics PLC | Professional & scientific | 2001 |
| Pickards Flooring Limited | Wholesale & retail | 2025 |
| Pigeon Ventures Ltd | Wholesale & retail | 2025 |
| Pineapple Foundry Limited | Professional & scientific | 2018 |
| Pineapple Homes Partnership Limited | Professional & scientific | 2025 |
| Pineapple Management Limited | Professional & scientific | 2017 |
| Pineapple Sustainable Partnerships Limited | Professional & scientific | 2017 |
| Pioneer Quality Solutions Ltd | Professional & scientific | 2024 |
| PIP IOT Ltd | Information & communication | 2018 |
| Pipes.Studio Ltd | Professional & scientific | 2025 |
| Pippins Property Ltd | Real estate | 2022 |
| Pitchmarking.Com Limited | Administrative & support | 2025 |
| Pixprop Ltd | Households | 2025 |