| PGP Decorators Limited | Construction | 2020 |
| Photon Design Ltd | Information & communication | 1998 |
| Picnic Academy Limited | Other services | 2023 |
| Picola Properties Limited | Construction | 2006 |
| Piermont Digital Consultancy Limited | Information & communication | 2020 |
| Pierre Optique Limited | Wholesale & retail | 2005 |
| Pink Recruitment Limited | Administrative & support | 2004 |
| PJS Roofing Limited | Construction | 2004 |
| Plowden Consulting Limited | Information & communication | 2007 |
| Plumbbob Limited | Other services | 2005 |
| Plumer Management Limited | Real estate | 1964 |
| Pogo Tattoo Ltd | Other services | 2021 |
| Portfolio Media Management Limited | Professional & scientific | 2003 |
| Power Fitness Limited | Real estate | 1999 |
| Power Isolators Limited | Manufacturing | 2005 |
| POWER2SMS Limited | Information & communication | 2016 |
| Premium Service Limited | Financial services | 2006 |
| Pretzkow Limited | Real estate | 1997 |
| Pride Mobility Home Store Limited | Wholesale & retail | 2023 |
| Pride Mobility Products Limited | Wholesale & retail | 1996 |
| Priory Orchard Limited | Professional & scientific | 2005 |
| Pro Espresso Ltd | Wholesale & retail | 2018 |
| Procare Healthcare Ltd | Health & social care | 2013 |
| Productive Consulting Limited | Information & communication | 1993 |
| Project Developments (UK) Limited | Construction | 1999 |
| Prokem (UK) Limited | Professional & scientific | 1998 |
| Prolificstore Limited | Wholesale & retail | 2026 |
| Promoting Sports in Community CIC | Arts & recreation | 2024 |
| Property Investment Management & Marketing Services Limited | Real estate | 2001 |
| Prosper 21 Limited | Professional & scientific | 2002 |
| Przybylski Consultations Ltd | Professional & scientific | 2022 |
| Purple Architects Limited | Professional & scientific | 2002 |
| Python Technology Limited | Information & communication | 1998 |
| QD Oxford UK Limited | Financial services | 2025 |
| Quality Outcomes Limited | Education | 2004 |
| Qume Ltd | Real estate | 2016 |
| Qytek Limited | Professional & scientific | 2006 |
| R & S Carpentry & Building Services Limited | Construction | 2006 |
| R Adams Limited | Extraterritorial | 2007 |
| R J Clarke Computing Limited | Information & communication | 1996 |
| R M Electrical Services Ltd. | Construction | 2003 |
| R N Pounds Limited | Construction | 2003 |
| R.P. Baker (Oxford) Limited | Real estate | 1980 |
| Ra-Co Securities Limited | Construction | 2001 |
| Raceparts Direct Limited | Financial services | 1997 |
| Racescene Limited | Arts & recreation | 1990 |
| Racetech Design Limited | Manufacturing | 1982 |
| Radcot Armoured Components | Manufacturing | 1998 |
| Radhan Ltd | Wholesale & retail | 2026 |
| Raptor Informatics Limited | Information & communication | 2004 |
| Ravenschild Ltd | Information & communication | 2008 |
| RAW Group Limited | Arts & recreation | 2005 |
| RAW World Ltd | Arts & recreation | 2005 |
| Rawlings Products Ltd | Administrative & support | 2021 |
| Rayer Limited | Administrative & support | 2006 |
| Realmusicrebels C.I.C. | Professional & scientific | 2026 |
| Recovery Support Services Ltd | Health & social care | 2018 |
| Red Horse Team Ltd | Health & social care | 2001 |
| Redshear Ltd | Information & communication | 2004 |
| Reesrussell Taxation Services Limited | Professional & scientific | 2006 |
| Refresh Websites Ltd | Information & communication | 2004 |
| Regal Engineering (Witney) Ltd | Construction | 1994 |
| Remarx Limited | Other services | 1996 |
| Renewable Energy Innovations Limited | Manufacturing | 2001 |
| Residential Projects Limited | Wholesale & retail | 1987 |
| Restal House Residents Association Limited | Real estate | 1981 |
| RGT Consultancy Limited | Real estate | 2023 |
| Richard Coxeter Limited | Wholesale & retail | 1993 |
| Richard Fortey Writing Limited | Administrative & support | 1998 |
| Richard Kirby: Quality Methods Limited | Professional & scientific | 2003 |
| Richardsons Financial Group Limited | Professional & scientific | 2003 |
| Richardsons Financial Services Limited | Financial services | 1987 |
| Richlee Deserved Limited | Information & communication | 2004 |
| Ringlease Limited | Real estate | 1986 |
| Riteweld Engineering Limited | Manufacturing | 2002 |
| River & Rowing Museum (Trading) Limited | Wholesale & retail | 1993 |
| River and Rowing Museum Foundation | Education | 1990 |
| River GOD Rvgd Limited | Other services | 2021 |
| Rj's Barbers Banbury Ltd | Other services | 2009 |
| Roam Developments Limited | Construction | 2025 |
| Roboto Studio Ltd | Information & communication | 2017 |
| Rock Solid Knowledge Ltd | Information & communication | 2009 |
| Rockstone Consultants Limited | Information & communication | 2002 |
| Rockwood Productions Ltd | Information & communication | 2021 |
| Rockwood Studios Limited | Information & communication | 2021 |
| Rogers & Rogers (Oxford) Limited | Real estate | 2000 |
| Rokos Capital Management LLP | | 2015 |
| Rokos Services (UK) Limited | Administrative & support | 2015 |
| Rolo Ltd | Real estate | 2015 |
| Roman Home Improvements Limited | Construction | 2018 |
| Rose Cottage Carpentry and Building Contractors Limited | Construction | 2011 |
| Rose Properties Limited | Real estate | 1998 |
| Rowland Plant Limited | Administrative & support | 2024 |
| Rowse Trading Limited | Wholesale & retail | 2002 |
| RPF Consultancy Limited | Professional & scientific | 2002 |
| Rspec Performance Products Ltd | Wholesale & retail | 2007 |
| Runrite Services Limited | Manufacturing | 1998 |
| S.A.S Developments Limited | Wholesale & retail | 2005 |
| Sahbaz Tailoring Services Ltd | Other services | 2022 |
| Sallins Limited | Information & communication | 1997 |