| Rowan Garden Centre Limited | Wholesale & retail | 2007 |
| Rowant Ltd | Professional & scientific | 2008 |
| Rowe and Rowe Consultancy Limited | Professional & scientific | 2020 |
| Rowes News Ltd | Administrative & support | 2017 |
| Rowsell Property Ltd | Real estate | 2020 |
| ROX Piri Piri Ltd | Hospitality | 2024 |
| Royale College of Oxford Ltd | Administrative & support | 2019 |
| Royale International Education Group Limited | Education | 2019 |
| Rozaara London Ltd | Wholesale & retail | 2025 |
| Rozana Oxford Limited | Hospitality | 2022 |
| RP Tyler Consulting Limited | Information & communication | 2003 |
| RQA Properties Ltd | Construction | 2025 |
| RR Alden Group Limited | Financial services | 2017 |
| RR Alden Oxford Limited | Wholesale & retail | 2003 |
| Rrclg Limited | Professional & scientific | 2006 |
| RS Jericho Trading Limited | Wholesale & retail | 2015 |
| RSB Marketing Limited | Professional & scientific | 2010 |
| Rsbmg Group Ltd | Real estate | 2023 |
| RSG Pharma Consultants Limited | Administrative & support | 2004 |
| RSH Developments (Oxford) Limited | Administrative & support | 2023 |
| Rste Consultancy Ltd | Construction | 2013 |
| RT Consultants (Oxford) Ltd | Professional & scientific | 2025 |
| RTH Harris Trading Limited | Financial services | 2018 |
| Rubicon Coaching Limited | Professional & scientific | 2011 |
| Rubies Kiddies World Ltd | Information & communication | 2026 |
| Ruby's Hair Studio Limited | Other services | 2023 |
| Ruchi's Dosapark Ltd | Hospitality | 2009 |
| Ruci Constructions Oxon Ltd | Construction | 2020 |
| Ruci Real Estate Ltd | Real estate | 2026 |
| Rudman & COX Ltd | Construction | 2024 |
| Rudman Electrical Limited | Construction | 2018 |
| Ruhaya Ltd | Construction | 2023 |
| Ruhazel and Co Ltd | Hospitality | 2018 |
| Rukard Medical Limited | Wholesale & retail | 2021 |
| Rule of Three Communications Limited | Information & communication | 2008 |
| Rulesolve Limited | Information & communication | 2014 |
| Run AI DM Consulting Ltd | Information & communication | 2025 |
| Rupani Investments Limited | Real estate | 2025 |
| Ruskin College | Education | 1900 |
| Ruskin England Limited | Wholesale & retail | 2023 |
| Ruslan Lialyk Limited | Construction | 2025 |
| Russell Acott Limited | Real estate | 1912 |
| Russell Whitlock Accountancy Ltd | Professional & scientific | 2011 |
| Russian Food Oxford Ltd | Wholesale & retail | 2011 |
| Rvad 108 Limited | Real estate | 2020 |
| Rvad Consultancy Limited | Professional & scientific | 2018 |
| Rvad Investments Limited | Real estate | 2020 |
| RW Accountancy Ltd | Extraterritorial | 2011 |
| RX Clin Research Limited | Administrative & support | 2013 |
| Ryan Thornton Limited | Professional & scientific | 2014 |
| Ryebeck Assets Holding Company Ltd | Financial services | 2015 |
| RYM Engineering Design Ltd | Professional & scientific | 2018 |
| Rytork Limited | Professional & scientific | 2003 |
| Ryze Power Europe Limited | Administrative & support | 2023 |
| Ryze Power Group Limited | Financial services | 2023 |
| Ryze Power Limited | Administrative & support | 2021 |
| S & C Carpentry Contractors Limited | Construction | 2017 |
| S & I Qureshi Limited | Real estate | 2023 |
| S & L Food Co. Ltd | Hospitality | 2021 |
| S & S Green Grocers Ltd | Wholesale & retail | 2017 |
| S & S Smart Construction Ltd | Construction | 2020 |
| S 1 Direct Ltd | Professional & scientific | 2013 |
| S and C Cafe Limited | Hospitality | 2025 |
| S Copley Communications Limited | Professional & scientific | 2024 |
| S Crowther Properties Ltd. | Real estate | 2016 |
| S F Willow Limited | Real estate | 2021 |
| S J Webb Electrical (Oxford) Limited | Construction | 2019 |
| S L G Charitable Trust Limited | Other services | 1970 |
| S L Smyth Ltd | Health & social care | 2024 |
| S N Chahal Ltd | Transport & logistics | 2026 |
| S P Alden Limited | Financial services | 2025 |
| S P L (Oxford) Limited | Real estate | 2015 |
| S Q Limited | Extraterritorial | 2000 |
| S Saproo Consultants Ltd | Other services | 2021 |
| S Silver Limited | Administrative & support | 2026 |
| S Sinclair's Ltd | Other services | 2014 |
| S&V Limited Company Limited | Health & social care | 2014 |
| S-Curve Economics Communications Ltd | Professional & scientific | 2026 |
| S. B. Sarr Painting Ltd | Construction | 2016 |
| S.A & O Limited | Real estate | 2019 |
| S.A.M Giorgio Ltd | Households | 2024 |
| S.A.S. (Business Equipment) Limited | | 1986 |
| S.E. Ison & Sons Ltd | Extraterritorial | 2015 |
| S.E.E. Collective Ltd | Hospitality | 2024 |
| S.J. Contracting Services Limited | Administrative & support | 1988 |
| S2 Beauty Limited | Other services | 2023 |
| S27 Events Limited | Administrative & support | 2012 |
| SA Building & Property Maintenance Limited | Construction | 2025 |
| SA Housing Ltd | Real estate | 2022 |
| SAB Property Renovation Limited | Construction | 2021 |
| Sabatini Homes (Oxford) Limited | Real estate | 2016 |
| Sabina DO Research Limited | Professional & scientific | 2023 |
| Sadlers Court Residents Association Limited | Households | 1977 |
| Sadm Limited | Information & communication | 2016 |
| SAF International Ltd | Wholesale & retail | 2019 |
| SAF Media Group Ltd | Wholesale & retail | 2024 |
| Safe Delivery Ltd | Transport & logistics | 2014 |
| Safe Home Removals Ltd | Transport & logistics | 2025 |
| Safe Port Engineering Solutions Ltd | Professional & scientific | 2026 |
| Safe Security and Events Limited | Administrative & support | 2004 |