| Rockyfilm Limited | Information & communication | 2018 |
| Rocma Freight Services Limited | Transport & logistics | 1989 |
| Roddens Aero Ltd | Manufacturing | 2020 |
| Rodi Composite Ltd | Manufacturing | 2026 |
| Rodrigo AC Composites Ltd | Manufacturing | 2019 |
| Roebuck Advisory Limited | Professional & scientific | 2026 |
| Roelectrical Services Ltd | Construction | 2026 |
| Roem Limited | Administrative & support | 2004 |
| Rogan Scott Ltd | Professional & scientific | 2025 |
| Roger Booker & Co Limited | Professional & scientific | 2016 |
| Roger Parker Associates Limited | Construction | 2014 |
| Roger Pierce Consulting Limited | Administrative & support | 2011 |
| Roger Stearn Electrical Contractors Limited | Construction | 2004 |
| Rogers Management Limited | Real estate | 2024 |
| Rogers Ventures Limited | Real estate | 2024 |
| Rogerson Consulting Services Limited | Professional & scientific | 2024 |
| Rokr Electrical Ltd | Wholesale & retail | 2026 |
| Rokudo Limited | Information & communication | 2013 |
| Rolfe Kentish Architect Limited | Professional & scientific | 2018 |
| Roline Technology (UK) Limited | Administrative & support | 2019 |
| Roll on Blank Tapes Ltd | Real estate | 2024 |
| Rollercoaster Publishing Ltd | Information & communication | 2025 |
| Rolls-Strandmann Ltd | Agriculture & fishing | 2017 |
| Rolvic Global Education Ltd | Administrative & support | 2023 |
| ROM4AIR Ltd | Manufacturing | 2025 |
| Roma Acai Limited | Arts & recreation | 2003 |
| Romania International Co., Ltd | Other services | 2021 |
| Romans’ Quarter (Bingham) Residential Management Company Limited | Households | 2021 |
| Romany Theatre Company C.I.C. | Arts & recreation | 2013 |
| Romarong Group Limited | Manufacturing | 2005 |
| Romarong Properties Limited | Real estate | 2010 |
| Romero UK Limited | Construction | 2006 |
| Romi Bear Biotech (Europe) Co., Ltd | Wholesale & retail | 2024 |
| Rommel DAN Ltd | Manufacturing | 2026 |
| Romsey Capital Limited | Professional & scientific | 2008 |
| Romsey Mill Trust | Health & social care | 1998 |
| Ronbei (UK) Industrial Co., Ltd | Professional & scientific | 2015 |
| Rong TAI (HK) Holding Limited | Extraterritorial | 2024 |
| Rongan Outdoor Ltd | Wholesale & retail | 2024 |
| Rongzhen Trading Co., Ltd | Wholesale & retail | 2023 |
| Ronis & Kids Properties Limited | Real estate | 2018 |
| Roocru Limited | Professional & scientific | 2016 |
| Roof Brothers Ltd | Construction | 2022 |
| Roof Gardens by Kris Koper Limited | Administrative & support | 2016 |
| Roofing Cambridge Ltd | Construction | 2024 |
| Roofing Contractors (Cambridge) Limited | Construction | 1963 |
| Roofing Direct Merchants Limited | Wholesale & retail | 2020 |
| Roofing Innovations Ltd | Construction | 2020 |
| Roofmodus Ltd | Construction | 2026 |
| Roofview Estate Limited | Real estate | 2024 |
| Room for ME Ltd | Hospitality | 2015 |
| Room Service Deliveries Limited | Wholesale & retail | 2002 |
| Rooms 101 Ltd | Hospitality | 2022 |
| Rooney Orthopaedics Limited | Health & social care | 2025 |
| Roost Coffee House Ltd | Hospitality | 2025 |
| Roost Coffee House Soham Ltd | Hospitality | 2026 |
| Roosterville Limited | Information & communication | 1999 |
| Root Delta Ltd | Information & communication | 2026 |
| Root International Limited | Wholesale & retail | 2023 |
| Rooted IC Ltd | Administrative & support | 2024 |
| Roots Travel & Tours Ltd | Administrative & support | 2020 |
| Rootstock Wines Ltd | Wholesale & retail | 2013 |
| ROP Trade Ltd | Wholesale & retail | 2025 |
| Ropeworks Management Company Limited | Households | 2013 |
| Roproxy Ltd | Wholesale & retail | 2024 |
| Rorut UK Ltd | Wholesale & retail | 2023 |
| Rory James Construction Limited | Construction | 2020 |
| ROS Stephens Consulting Ltd | Professional & scientific | 2012 |
| Rosamin Ltd Ltd | Professional & scientific | 2022 |
| Rose and Cooper Developments Ltd | Construction | 2005 |
| Rose and DER Software Ltd | Wholesale & retail | 2023 |
| Rose Bathroom Co., Ltd | Manufacturing | 2020 |
| Rose Gardens (Weston) Management Company Limited | Households | 2022 |
| Rose Hometown Limited | Wholesale & retail | 2025 |
| Rose Street Ltd | Wholesale & retail | 2018 |
| Rose Wave Ltd | Manufacturing | 2025 |
| Roseanne Wilkinson Medical Writing Ltd | Professional & scientific | 2016 |
| Rosebrook Developments Limited | Construction | 2014 |
| Rosebuds Nursery Ltd | Education | 2024 |
| Rosebury Housing Limited | Real estate | 2021 |
| Roseey Trade Limited | Extraterritorial | 2014 |
| Rosehill Residential Ltd | Real estate | 2023 |
| Roselead (Wattisham) Limited | Real estate | 2006 |
| Roselead Holdings Limited | Professional & scientific | 2000 |
| Roselead Limited | Real estate | 1999 |
| Roseman Properties Limited | Real estate | 2018 |
| Rosemary Catering Ltd | Hospitality | 2022 |
| Rosemary Events and Catering Limited | Hospitality | 2024 |
| Rosemary Lane Cambridge Management Co. Ltd | Households | 2017 |
| Rosetta Digital Limited | Information & communication | 2020 |
| Rosette Multi-Word Ltd | Professional & scientific | 2018 |
| Rosewood and Stone Ltd | Construction | 2020 |
| Rosewood Stud Limited | Administrative & support | 2007 |
| Rosewood Stud Park Ltd | Hospitality | 2021 |
| Rosie Franks Limited | Information & communication | 2015 |
| Rosie Lettings Ltd | Real estate | 2025 |
| Rositys Limited | Other services | 2016 |
| Roskel Contracts Limited | Construction | 1968 |
| Roskel Holdings 2017 Limited | Construction | 2017 |
| Roskel Holdings 2024 Limited | Construction | 2024 |