| Repair Experts Bicester Limited | Manufacturing | 2018 |
| Repertoire Limited | Professional & scientific | 2025 |
| Resale Services Limited | Other services | 2007 |
| Research Consultancy Solutions Limited | Professional & scientific | 2022 |
| Research Remora Ltd | Professional & scientific | 2022 |
| Resi Consultancy Ltd | Professional & scientific | 2021 |
| Resow Capital Ltd | Real estate | 2023 |
| Restaurant Ventures Limited | Other services | 1997 |
| RESTOR8IV Limited | Wholesale & retail | 2019 |
| Revo Environmental Limited | Water & waste | 2006 |
| Revs Property Maintenance Ltd | Construction | 2014 |
| Rewild & Bloom CIC | Agriculture & fishing | 2026 |
| REY Ventures Ltd | Real estate | 2025 |
| Reynard Property Limited | Construction | 2013 |
| Reynard Racing Cars Limited | Professional & scientific | 2002 |
| RG Transformations Limited | Information & communication | 2019 |
| RGA Bicester LLP | | 2019 |
| RGW Homes Limited | Real estate | 2017 |
| RH Kerr Ltd | Real estate | 2026 |
| Rhdc Henley Limited | Health & social care | 2012 |
| RHL (Long Crendon) Limited | Construction | 2012 |
| Richard Carver Limited | Education | 2014 |
| Richard Chadwick Sales Limited | Administrative & support | 2006 |
| Richard Owen Plumbing and Heating Limited | Construction | 2014 |
| Ridgemount Technologies Limited | Manufacturing | 1995 |
| Rightstep Mortgages Ltd | Financial services | 2020 |
| Rini Anet Healthcare Limited | Health & social care | 2019 |
| Risebridge Properties Ltd | Real estate | 2024 |
| Risebridge Property Investments LLP | | 2024 |
| Rising Star Properties Limited | Real estate | 2022 |
| Risk to Resolution Ltd | Professional & scientific | 2019 |
| Riverhall Ltd | Construction | 2014 |
| RJ Investments Limited | Real estate | 2016 |
| RJH Landscapes Limited | Administrative & support | 2012 |
| RKC Smiles Ltd | Health & social care | 2022 |
| RKL Estates Ltd | Professional & scientific | 2025 |
| RKS Business Limited | Wholesale & retail | 2017 |
| RKS Transport Services Ltd | Wholesale & retail | 2023 |
| RLB Accountancy Services Limited | Professional & scientific | 2014 |
| RM Engineering Solutions Limited | Professional & scientific | 2014 |
| RML Construction Services Limited | Professional & scientific | 2012 |
| Rmpt Bicester Limited | Manufacturing | 2025 |
| Rncp Ltd | Real estate | 2025 |
| RNR Property Developments Ltd | Real estate | 2014 |
| ROB Troy Limited | Professional & scientific | 2008 |
| Robert Browne's Farms (Tusmore) Limited | Agriculture & fishing | 1978 |
| Robert Lund Building Limited | Construction | 2018 |
| Roberts & Sheppey (Melrose) Ltd. | Wholesale & retail | 2013 |
| Robin Accounting Limited | Professional & scientific | 2025 |
| Robin Herd Limited | Professional & scientific | 1989 |
| Robin Trade Ltd | Information & communication | 2012 |
| Robinson Properties Ltd | Real estate | 2024 |
| Robotech Global Limited | Information & communication | 2006 |
| Rocco-Sienna Ltd | Wholesale & retail | 2020 |
| Rock Capital Group Ltd | Administrative & support | 2018 |
| Rockland Electrical (UK) Ltd | Construction | 2014 |
| Roda Technology Ltd | Information & communication | 2021 |
| Roduch Developments Limited | Construction | 2019 |
| Rodwells Ltd | Information & communication | 2020 |
| Rogue Consulting Limited | Information & communication | 2010 |
| Roof Services Limited | Real estate | 2023 |
| Rooms That Rock Ltd | Real estate | 2016 |
| Roots Educational Psychology Services Limited | Education | 2025 |
| Rosara (Outdoor Style) Ltd | Financial services | 2016 |
| Rosara @ Nicholsons Ltd | Wholesale & retail | 2025 |
| Roseland Garden Centre Ltd | Wholesale & retail | 2025 |
| Roseland Stores Limited | Wholesale & retail | 2014 |
| Rosemaryy Ltd | Wholesale & retail | 2026 |
| Rosford Carpentry Ltd | Construction | 2015 |
| Rosinka - Oxford Children's Centre LLP | | 2010 |
| Rotari Recovery Limited | Transport & logistics | 2025 |
| Rowfit Ltd | Arts & recreation | 2018 |
| RPD Services(Uk) Ltd | Professional & scientific | 2024 |
| RRLJ001 Ltd | Real estate | 2025 |
| Rsji Logistics Limited | Transport & logistics | 2025 |
| RT Construction Services Ltd | Construction | 2018 |
| Ruby Nail and Beauty Ltd | Other services | 2025 |
| Rugs and Lather Ltd | Other services | 2026 |
| Rundle Investments Ltd | Real estate | 2023 |
| Rural Properties (Hindon) Limited | Real estate | 1996 |
| Rural Properties (Holdings) Limited | Real estate | 2009 |
| Rural Small Scale Industry Development UK Limited | Real estate | 2010 |
| Rush Taverns Ltd | Hospitality | 2025 |
| Rushworth Residential Ltd | Real estate | 2026 |
| Rustica Bistrot Bicester Limited | Hospitality | 2025 |
| Rusty Hound Fabrications Ltd | Extraterritorial | 2024 |
| RVJ Healthcare Ltd | Other services | 2016 |
| RVR Informatics Ltd | Transport & logistics | 2014 |
| RVR Properties(Uk) Ltd | Real estate | 2021 |
| RWT Associates Limited | Administrative & support | 2015 |
| Ryan Edwards Exhaust Fabrication Limited | Manufacturing | 2015 |
| RYE Apartments Limited | Households | 2002 |
| RYE Villa Property Limited | Real estate | 2026 |
| S & G Consulting Services Limited | Financial services | 2019 |
| S & G Estates Limited | Real estate | 2014 |
| S & G Investment Property Limited | Real estate | 2019 |
| S & S Frelick Holdings Limited | Information & communication | 2024 |
| S E SKI Club Limited | Arts & recreation | 2012 |
| S F Accountancy & Advisory Ltd | Professional & scientific | 2026 |
| S French Flooring Limited | Construction | 2022 |