| Rink Construction Ltd | Construction | 2021 |
| Rinns Ventures Limited | Real estate | 2024 |
| Rinsey Drive Management Company Limited | Households | 2023 |
| RIO Property Group Ltd | Real estate | 2026 |
| Rise Factory Ltd | Manufacturing | 2020 |
| Risehivedigital Ltd | Wholesale & retail | 2026 |
| Rishi Traders & Co Ltd | Hospitality | 2026 |
| Rising Spirit Enterprises LLP | | 2020 |
| Risinghurst Superstore Ltd | Wholesale & retail | 2020 |
| Risk Management Options Ltd | Professional & scientific | 2012 |
| Risq Fitness Ltd | Wholesale & retail | 2023 |
| Ritan Enterprises Limited | Real estate | 2013 |
| Ritetech Limited | Wholesale & retail | 2017 |
| River GEM Ltd | Real estate | 2024 |
| River Hotel Limited | Hospitality | 2008 |
| River Learning Trust | Education | 2012 |
| River Productions Limited | Information & communication | 1998 |
| River Thame Conservation Trust | Professional & scientific | 2013 |
| River Therapeutics Ltd | Professional & scientific | 2022 |
| RIVERBEACH85 Limited | Hospitality | 2014 |
| Riverside Park Portfolio One Limited | Real estate | 2021 |
| Riverside Park Portfolio Two Limited | Real estate | 2021 |
| Riverside Sunrise Services Limited | Professional & scientific | 2025 |
| Rivett Technologies Ltd | Wholesale & retail | 2023 |
| RJS Medical Services Ltd | Health & social care | 2019 |
| RJS Removals Ltd | Transport & logistics | 2023 |
| RK Asset Group Ltd | Financial services | 2025 |
| RK Associates (Oxford) Ltd | Professional & scientific | 2017 |
| RK Food Production Ltd | Manufacturing | 2025 |
| RLB Brothers Property Ltd | Real estate | 2020 |
| RLK Heating Services Ltd | Professional & scientific | 2024 |
| RMA Estates Limited | Real estate | 2005 |
| RMA Investments Limited | Real estate | 2000 |
| RME Consultants Limited | Administrative & support | 2019 |
| RMH Estates Ltd | Real estate | 2025 |
| RMZ Heating & Electrical Ltd | Construction | 2019 |
| RND Advisory Limited | Professional & scientific | 2026 |
| Roadcircles Limited | Wholesale & retail | 2018 |
| Roadway Construction Ltd | Construction | 2019 |
| Robash Limited | Health & social care | 2023 |
| Robert a J Matthews Limited | Professional & scientific | 2008 |
| Robert DRE Support Services Ltd | Administrative & support | 2016 |
| Robert Jones Rare Books Limited | Administrative & support | 2005 |
| Robertson's Homes Ltd | Construction | 2020 |
| Robin's Court (Wheatley) Limited | Households | 2014 |
| Robiz Solutions Limited | Other services | 2026 |
| Robotime Leisure UK Limited | Wholesale & retail | 2021 |
| Robust Services Ltd | Administrative & support | 2021 |
| Rockedge Holdings Limited | Real estate | 2021 |
| Rocknrollyogi Ltd | Arts & recreation | 2026 |
| Rocky's Food Corner Limited | Wholesale & retail | 2024 |
| Rodeena Ltd | Wholesale & retail | 2020 |
| Roderick a Smith Consulting Engineer Ltd | Professional & scientific | 2015 |
| Rohma Consultancy Ltd | Health & social care | 2021 |
| Rohme Limited | Wholesale & retail | 2026 |
| Rokalin Pharmaceuticals Ltd | Manufacturing | 2024 |
| Rolix Properties Ltd | Real estate | 2024 |
| Roller Films Limited | Information & communication | 2021 |
| Rolsarguy Limited | Professional & scientific | 2023 |
| Romagnoli Cleaning Services Ltd | Administrative & support | 2026 |
| Roman Bogdan Ltd | Transport & logistics | 2018 |
| Roman's Renovations Ltd | Construction | 2012 |
| Romat Ventures Ltd | Manufacturing | 2026 |
| Romeyo Ltd | Professional & scientific | 2025 |
| Rona Food Ltd | Hospitality | 2020 |
| Ronin Theatre Productions Community Interest Company | Arts & recreation | 2017 |
| Roof Doctor Oxford Limited | Construction | 2012 |
| Rooftest Limited | Construction | 2007 |
| Root & Rise Soul Fuel Ltd | Hospitality | 2025 |
| Rooted and Rising KJT Ltd | Wholesale & retail | 2026 |
| Rooted in Place CIC | Professional & scientific | 2025 |
| Roots Farm Limited | Real estate | 2010 |
| Roots Funding Ltd | Financial services | 2023 |
| Ropat Services Limited | Other services | 2013 |
| Rory Carnegie Photography Limited | Arts & recreation | 2008 |
| Rosa Productions Ltd | Information & communication | 2011 |
| Rosamund Court Management Company Limited | Hospitality | 2000 |
| Rosati Ltd | Manufacturing | 2017 |
| Rose & Barber Ltd | Real estate | 2024 |
| Rose Blessed Limited | Health & social care | 2022 |
| Rose Court Freehold Company Limited | Real estate | 2012 |
| Rose Garden Food Ltd | Hospitality | 2025 |
| Rose Hill and Donnington Advice Centre Limited | Other services | 2007 |
| Rosemount Accountancy Ltd | Professional & scientific | 2014 |
| Rosenburg Gold Ltd | Manufacturing | 2021 |
| Rosepalm Properties Limited | Real estate | 1994 |
| Rosepine Limited | Professional & scientific | 2015 |
| Roseview Property Management Limited | Real estate | 2026 |
| Rosewood Accommodations Ltd | Real estate | 2023 |
| Rosewood Joinery Oxford Ltd | Manufacturing | 2017 |
| Rosneath Consulting Limited | Professional & scientific | 2018 |
| Ross G J Henderson Ltd. | Manufacturing | 2016 |
| Roth Rail Consultancy Ltd | Professional & scientific | 2022 |
| Rotherslade Limited | Professional & scientific | 2017 |
| Rotonda Coffee Ltd | Wholesale & retail | 2024 |
| Rougemont Security Ltd | Administrative & support | 2023 |
| Roundtheclocksmith Ltd | Manufacturing | 2025 |
| Routes Coffee Limited | Hospitality | 2015 |
| Routes Coffee Roasters Ltd | Manufacturing | 2018 |
| Rover + Toil Ltd | Manufacturing | 2020 |