| PWF Construction Limited | Construction | 2020 |
| Q Build Property Limited | Real estate | 2022 |
| Q.S Group Services Ltd | Administrative & support | 2022 |
| Qgril Ltd | Hospitality | 2024 |
| Qjcp Limited | Real estate | 2019 |
| Qlode Ltd | Information & communication | 2024 |
| Quaify Consulting Limited | Information & communication | 2026 |
| Qualyes Ltd | Professional & scientific | 2022 |
| QUE Pasta Ltd | Hospitality | 2025 |
| Quick Cars (Bicester) Limited | Transport & logistics | 2016 |
| Quilk Tech Solutions Ltd | Wholesale & retail | 2024 |
| Quince and Clover at Great TEW Ltd | Hospitality | 2020 |
| Quince and Clover Ltd. | Hospitality | 2018 |
| Quince and Clover on the Square Limited | Hospitality | 2025 |
| Quinrow Limited | Real estate | 2025 |
| Quno Limited | Administrative & support | 2008 |
| R & D Developments (Bicester) Ltd | Construction | 2016 |
| R & J Berry & Sons | | 1990 |
| R & K Major Farm Services Limited | Water & waste | 2011 |
| R & M Properties (Oxford) Limited | Real estate | 2025 |
| R & T Read Limited | Agriculture & fishing | 2020 |
| R a Shayler & SON Limited | Construction | 2014 |
| R Debney Associates Limited | Health & social care | 2013 |
| R H Tank Services Limited | Mining & quarrying | 2013 |
| R J Plested Limited | Construction | 2017 |
| R S Properties (2000) Ltd | Real estate | 2014 |
| R Tyler Roofing Limited | Construction | 2017 |
| R W Machines Limited | Wholesale & retail | 1982 |
| R W V Transportation Limited | Information & communication | 2023 |
| R&F Renewables Limited | Construction | 2025 |
| R&M Couriers Ltd | Transport & logistics | 2022 |
| R&M UK Trading Ltd | Wholesale & retail | 2024 |
| R. Aunins Engineering Ltd | Manufacturing | 2021 |
| R.C. & Sons Limited | Administrative & support | 2014 |
| R.D. Mallory Milking Machines & Dairy Supplies Limited | Manufacturing | 1991 |
| R.S. Assemblies Limited | Manufacturing | 1978 |
| Radius Freehold Limited | Real estate | 2019 |
| Radley Solar Systems Limited | Construction | 2010 |
| RAF Upper Heyford Heritage Centre | Arts & recreation | 2012 |
| Railway Kontrol Design Solutions Limited | Professional & scientific | 2017 |
| Rainbow Homes (Oxford) Ltd | Administrative & support | 2006 |
| Raipiar Limited | Wholesale & retail | 2025 |
| RAM Dental Ltd | Health & social care | 2016 |
| Ramji Care Services Ltd | Health & social care | 2019 |
| Rangecastle Limited | Real estate | 2000 |
| Ranzteq Ltd | Information & communication | 2020 |
| Rapid Design and Prototype Group LLP | | 2025 |
| Rapid Engineering N.E. Limited | Professional & scientific | 2003 |
| Rapid Engineering Supplies Limited | Wholesale & retail | 2025 |
| Rasha Kashou Studio Limited | Wholesale & retail | 2022 |
| Raspio Ltd. | Information & communication | 2017 |
| Ratec Research Limited | Manufacturing | 2001 |
| Ratheruseful Limited | Health & social care | 2017 |
| Ratledge Enterprises Limited | Health & social care | 2021 |
| Raven Media Group Ltd | Information & communication | 2023 |
| Ravendrive Limited | Real estate | 1975 |
| Ravensburger Limited | Manufacturing | 1964 |
| Rawes Estates Ltd | Real estate | 2025 |
| RB Pinsa Bicester Limited | Hospitality | 2026 |
| Rbib Ltd | Financial services | 2019 |
| Rbishwas Ltd | Real estate | 2024 |
| RDA Business Consulting Ltd | Professional & scientific | 2019 |
| RDP Group Investments Ltd | Real estate | 2025 |
| RDR Estates & Holdings Ltd | Real estate | 2025 |
| Re-Universe Group Limited | Information & communication | 2025 |
| Re-Universe Ltd | Information & communication | 2018 |
| React Industrial Solutions Ltd | Professional & scientific | 2015 |
| React(Oxford) Limited | Financial services | 2024 |
| Ready Design and Technology Limited | Professional & scientific | 2008 |
| Readyops Ltd | Wholesale & retail | 2024 |
| Real Driving Ltd | Education | 2014 |
| Real Expert Limited | Real estate | 2005 |
| Rebalance Wellbeing Hub CIC | Health & social care | 2025 |
| Rectory House Dental Practice Limited | Health & social care | 2009 |
| Recycled Audio Limited | Manufacturing | 2004 |
| Red Baboon Studios Limited | Professional & scientific | 2020 |
| Red Chain Games Limited | Information & communication | 2008 |
| Red Stone Retail Recruitment Ltd | Extraterritorial | 2007 |
| Redding Consulting Ltd | Professional & scientific | 2026 |
| Redhill Orthodontics Limited | Health & social care | 2017 |
| Redline Fitness Ltd | Arts & recreation | 2024 |
| Redline Public Relations Limited | Professional & scientific | 1999 |
| Redsky Facilities Management Limited | Administrative & support | 2023 |
| Rees Collison Limited | Hospitality | 2000 |
| Reese Procurement Limited | Professional & scientific | 2013 |
| Regeneration Thame Limited | Construction | 2011 |
| Regents Valley Properties Ltd | Real estate | 2022 |
| REH Kendermann (UK) Limited | Wholesale & retail | 1992 |
| Reign Engineering Solutions Limited | Information & communication | 2025 |
| Reign of Edward Ltd | Information & communication | 2021 |
| Rejuvenate Hub & Wellbeing CIC | Health & social care | 2026 |
| Reklaw Creative Limited | Arts & recreation | 2017 |
| Reliance Auto Test Bicester Limited | Wholesale & retail | 2015 |
| Remy Kruse Ltd | Wholesale & retail | 2023 |
| Remya Ltd | Health & social care | 2021 |
| REN Property Investments Limited | Real estate | 2019 |
| Renace Agency Ltd | Professional & scientific | 2026 |
| Renew Perspectives Limited | Professional & scientific | 2024 |
| Rentrealm Ltd | Real estate | 2025 |
| Repair & Maintenance Group Limited | Wholesale & retail | 2021 |