| Richard Robert Hairdressing Limited | Other services | 2017 |
| Riches Advisory Limited | Professional & scientific | 2024 |
| Rickmansworth Sports Cars Limited | Wholesale & retail | 2008 |
| Rickmansworth Aesthetics Limited | Other services | 2005 |
| Rickmansworth Artificial Grass Pitch Limited | Arts & recreation | 2016 |
| Rickmansworth Bookkeeping and Accountancy Services Ltd | Professional & scientific | 2014 |
| Rickmansworth Bowls Club Limited | Arts & recreation | 2025 |
| Rickmansworth Enterprises Limited | Extraterritorial | 2013 |
| Rickmansworth Hockey Club Limited | Arts & recreation | 2016 |
| Rickmansworth Homes and Lettings Limited | Real estate | 2013 |
| Rickmansworth Properties Limited | Professional & scientific | 2000 |
| Rickmansworth School | Education | 2011 |
| Rickmansworth School Enterprises Limited | Arts & recreation | 2018 |
| Rickmansworth Waterways Trust Limited | Education | 1991 |
| Rickshaw Travels (UK) Limited | Administrative & support | 2009 |
| Ridgelodge Estates Ltd | Real estate | 2021 |
| RIG FX Ltd | Information & communication | 2018 |
| Rigger Ralph Services Ltd | Other services | 2025 |
| RIK Medical Services Ltd | Health & social care | 2015 |
| Riley IT Consulting Ltd | Information & communication | 2019 |
| Risha Care Ltd | Health & social care | 2018 |
| Rituals of Chai Ltd | Wholesale & retail | 2025 |
| Rituandco Ltd | Wholesale & retail | 2026 |
| River Commercial Limited | Professional & scientific | 2014 |
| River Property Advisors Ltd | Real estate | 2020 |
| Riverbay Properties Limited | Real estate | 2015 |
| Riverbirch Limited | Professional & scientific | 2024 |
| Riverside Dental Spa Limited | Health & social care | 2025 |
| Rivingtons Lifestyle Management Limited | Administrative & support | 2006 |
| Riyastealstop Limited | Wholesale & retail | 2026 |
| RIZ Capital Limited | Professional & scientific | 2006 |
| Rjnickelsserviceslimited Ltd | Construction | 2026 |
| RJS Group Ltd | Households | 2020 |
| Rk&W Properties Limited | Real estate | 2023 |
| RLT Management Limited | Real estate | 2022 |
| RMR Consultancy Ltd | Professional & scientific | 2026 |
| RMS Consulting Services Limited | Professional & scientific | 2024 |
| RN 78 Building Services Ltd | Construction | 2023 |
| Rnbn Limited | Information & communication | 2016 |
| Robert Construction & Consulting Limited | Manufacturing | 2026 |
| Robofun Ltd | Education | 2020 |
| Rocco's Pizza (UK) Limited | Professional & scientific | 1998 |
| Rocha Investment Ltd | Real estate | 2017 |
| Rocket Graphics Limited | Arts & recreation | 1995 |
| Rocket Motorsport Ltd | Arts & recreation | 2026 |
| Rocketworld Limited | Administrative & support | 1996 |
| Rofant Road Ltd | Real estate | 2024 |
| Rolf Wilson Limited | Arts & recreation | 2011 |
| Roman Education & Careers Ltd | Education | 2024 |
| Ronak Ltd | Hospitality | 2024 |
| Ronald Searle Cultural Estate Limited | Other services | 2012 |
| Roni C Bernstorff Electrical Ltd | Construction | 2025 |
| Roocovery Ltd | Education | 2017 |
| ROOM442 Limited | Administrative & support | 2012 |
| Rooney Ltd | Transport & logistics | 2013 |
| Roosevelt Properties Limited | Real estate | 2019 |
| Ropemakers Ltd | Other services | 2017 |
| Rosanna Rubin Coaching & Consulting Ltd | Professional & scientific | 2026 |
| Rose Insure & Protect Limited | Financial services | 2021 |
| Roshanuk Limited | Information & communication | 2014 |
| Roughwood Ventures Ltd | Wholesale & retail | 2026 |
| Roundsco Ltd | Real estate | 2025 |
| Route Portal Limited | Information & communication | 2025 |
| Router This World Scenery Ltd | Construction | 2025 |
| RP Bellegrove Ltd | Real estate | 2016 |
| RP UK Holdings Limited | Construction | 2022 |
| RP Wealth Limited | Financial services | 2024 |
| RPG13 Ltd | Hospitality | 2018 |
| RR Investment Enterprises Limited | Real estate | 2024 |
| RRR Group Limited | Construction | 2025 |
| RSJ Electricals Limited | Manufacturing | 2023 |
| RSJ Fisheries 2 Limited | Hospitality | 2017 |
| RSJ Fisheries Limited | Hospitality | 2012 |
| RSM Consultants Limited | Health & social care | 2007 |
| RST Global Solutions Holdings Limited | Mining & quarrying | 2015 |
| RT Support Ltd | Health & social care | 2019 |
| RTB Investments Limited | Arts & recreation | 2008 |
| Rubbish Brother’S Ltd | Water & waste | 2025 |
| Rubble Master UK Limited | Manufacturing | 2006 |
| Rubinstein Taybi Syndrome Support Group | Health & social care | 2011 |
| Ruby Grange Homecare Limited | Health & social care | 2016 |
| RUD Trading Limited | Wholesale & retail | 2017 |
| Ruislip Press Limited | Manufacturing | 1947 |
| Ruislip Press Properties Limited | Real estate | 1949 |
| Ruse Constructions Ltd | Manufacturing | 2024 |
| Russell Logistics (UK) Limited | Transport & logistics | 2007 |
| Rusty CJ Services Ltd | Information & communication | 2008 |
| Ruth Munroe Consulting Limited | Administrative & support | 2012 |
| Ruth Patel Coaching Ltd | Professional & scientific | 2025 |
| Rutherford Projects (London) Ltd | Real estate | 2016 |
| RW Lamont Ltd | Arts & recreation | 2014 |
| RYE Group Limited | Financial services | 2018 |
| Rytex Ltd | Wholesale & retail | 2020 |
| Ráfa Padel Ltd | Wholesale & retail | 2025 |
| S & J Beckley Services Ltd | Administrative & support | 2025 |
| S & J Events Catering Limited | Hospitality | 2015 |
| S and J Inns Limited | Hospitality | 2009 |
| S D Advisory Limited | Administrative & support | 2010 |
| S Thompson Creative Ltd | Professional & scientific | 2012 |
| S&S Business Ltd | Other services | 2020 |