| Richard Hough (Building) Limited | Construction | 1984 |
| Richard J. Balzer & Associates, Inc. | | 2004 |
| Richard Jackson Surgical Enterprise Ltd | Health & social care | 2025 |
| Richard Joyce Ltd | Professional & scientific | 2014 |
| Richard Price Plastic Surgery Ltd | Health & social care | 2003 |
| Richard Sharman Ltd | Professional & scientific | 2004 |
| Richardson’S Properties Ltd | Real estate | 2023 |
| Richmond Hides Limited | Wholesale & retail | 2013 |
| Rickard Animals Company Limited | Other services | 2018 |
| Rickard Cats Company Limited | Other services | 2018 |
| Rickard Development Company Limited | Construction | 2018 |
| Rico Technology Co., Ltd | Wholesale & retail | 2021 |
| Ricos Coffee Ltd | Wholesale & retail | 2017 |
| Ride Cambs Ltd | Transport & logistics | 2023 |
| Ridenova Cars Ltd | Transport & logistics | 2024 |
| Ridgeon Estate (Norwich) Limited | Real estate | 2013 |
| Ridgeon Estate Company Limited | Real estate | 1953 |
| Ridgepoint Consulting Limited | Professional & scientific | 2015 |
| Ridgeshire Limited | Construction | 1986 |
| Ridgeview Financial Services LLP | | 2011 |
| Ridley Hall, Cambridge | Education | 2014 |
| Rigel Star Ltd | Professional & scientific | 2021 |
| Rightroute Ltd | Professional & scientific | 2025 |
| Rigor Precision Engineers Ltd | Professional & scientific | 2018 |
| Rigorous Engineering Ltd | Professional & scientific | 2026 |
| Riiface Limited | Professional & scientific | 2023 |
| Rikar Ltd | Other services | 2015 |
| Rikiaks Ltd | Wholesale & retail | 2023 |
| RIL Consulting Limited | Professional & scientific | 2007 |
| Rilen Executive Chauffeurs Ltd | Transport & logistics | 2019 |
| Riley's Grounds Maintenance Ltd | Administrative & support | 2021 |
| Rima Property Ltd | Real estate | 2025 |
| Ringfenced Ltd | Administrative & support | 2026 |
| Ringfort 2 Management Limited | Households | 2016 |
| Ringstone Management Company Limited | Real estate | 2006 |
| Ringwood Investments Limited | Real estate | 1993 |
| Rinnovo Consulting Limited | Professional & scientific | 2023 |
| Rintoul Company Ltd | Health & social care | 2026 |
| RIO Capital Advisers Ltd | Financial services | 2014 |
| RIO Capital Investments Ltd | Financial services | 2015 |
| Riodove Services Limited | Professional & scientific | 2010 |
| Rippa Machinery Group Company Limited | Manufacturing | 2023 |
| Ripple Capital Ltd | Financial services | 2024 |
| Ripple Enterprises Ltd. | Wholesale & retail | 2014 |
| Ripple Events Limited | Extraterritorial | 2015 |
| Risc OS Open Limited | Information & communication | 2006 |
| Rise Above Partners Ltd | Professional & scientific | 2020 |
| Rise Above Scaffolding Ltd | Construction | 2023 |
| Risel Ltd | Wholesale & retail | 2023 |
| Riseup Innovative Solutions PVT Ltd | Information & communication | 2026 |
| Risilience Limited | Information & communication | 2015 |
| Risingstart Ltd | Arts & recreation | 2025 |
| Risqium Ltd | Information & communication | 2026 |
| Risx Properties Ltd | Real estate | 2015 |
| Risx Ventures Ltd | Financial services | 2015 |
| Rita & Rosario Ltd | Hospitality | 2013 |
| Ritho Limited | Information & communication | 2022 |
| Rito by Valentina Ltd | Wholesale & retail | 2024 |
| Rittel Consulting Ltd | Administrative & support | 2015 |
| Rivelta Limited | Wholesale & retail | 2025 |
| River & Wind Enterprise Ltd | Other services | 2010 |
| River CAM Finco Limited | Financial services | 2025 |
| River CAM Group Ltd | Professional & scientific | 2025 |
| River CAM Punting Limited | Administrative & support | 2015 |
| River Cambs Ltd | Real estate | 2024 |
| River Place (ST. Ives) Management Company Limited | Households | 2004 |
| Riverchurch Property Ltd | Real estate | 2017 |
| Riverdale (Norwich Road) Company Limited | Households | 2004 |
| Riverdene Accounting Ltd | Professional & scientific | 2009 |
| Riverlane Ltd | Information & communication | 2016 |
| Riverside Court Hitchin Management Limited | Households | 2007 |
| Riverside Freehold Management (Cambridge) Limited | Households | 1987 |
| Riverside Marine Renovations Ltd | Manufacturing | 2022 |
| Riverside Radiology Ltd | Health & social care | 2021 |
| Riverside Walk (Surfleet) Management Company Limited | Households | 2022 |
| Riverview Bloodstock Ltd | Agriculture & fishing | 2017 |
| Rivet Bidco Limited | Financial services | 2025 |
| Riveting Solutions Ltd | Manufacturing | 2024 |
| Rivey International LLP | | 2013 |
| Riviana Foods Limited | Professional & scientific | 1951 |
| RIX Racing Ltd | Arts & recreation | 2025 |
| Rixon Architecture Limited | Professional & scientific | 2016 |
| Rizbiz Projects Ltd | Wholesale & retail | 2025 |
| Rizi AI & Biorobotics Community Interest Company | Energy | 2025 |
| Rizwan Enterprises Limited | Hospitality | 2008 |
| RJ Reinforcements Limited | Construction | 2014 |
| RJ Vellacott Consulting Limited | Professional & scientific | 2019 |
| RJC Roofing Solutions Limited | Construction | 2023 |
| RJE Associates Ltd | Professional & scientific | 2019 |
| RJG Holidays Ltd | Administrative & support | 2021 |
| RJH Development Limited | Construction | 2008 |
| Rjmg Consultancy Ltd | Professional & scientific | 2022 |
| RJN Hotels Limited | Hospitality | 2004 |
| RJP Cambridge Limited | Wholesale & retail | 2023 |
| RJP Limited | Wholesale & retail | 2009 |
| RJS Heating Solutions Limited | Construction | 2023 |
| RJS Holdings Ltd | Real estate | 2018 |
| Rjtzz.Cro Ltd | Construction | 2026 |
| RK Detailing Ltd | Manufacturing | 2026 |
| RK Precision Components Ltd | Manufacturing | 2016 |