| Rococo Windows & Doors Ltd | Construction | 2022 |
| Rods Electrical Limited | Construction | 2026 |
| ROE Buck Holdings Limited | Real estate | 2020 |
| Roger Ward Building Ltd | Construction | 2019 |
| Rogers EV Ltd | Professional & scientific | 2019 |
| Roke Manor Research Limited | Information & communication | 1932 |
| Rokk Demolition & Salvage Limited | Construction | 2017 |
| Rokk Demolition Ltd | Construction | 2023 |
| Rolwey Group Limited | Manufacturing | 1990 |
| Rolwey Holdings Limited | Financial services | 2021 |
| Roman Children's Cardiology Ltd | Health & social care | 2017 |
| Romsey and Chandlers Ford Tree and Landscape Services Ltd | Administrative & support | 2021 |
| Romsey Bridal Boutique Limited | Wholesale & retail | 2015 |
| Romsey Business Consortium | Administrative & support | 2005 |
| Romsey Conservatory Company Limited | Construction | 2022 |
| Romsey Developments Limited | Construction | 2013 |
| Romsey Drum HUT Ltd | Arts & recreation | 2022 |
| Romsey E & J Limited | Hospitality | 2023 |
| Romsey Electrical Services Limited | Construction | 2019 |
| Romsey Fast Fit Limited | Wholesale & retail | 2007 |
| Romsey Garage Services Ltd | Wholesale & retail | 2024 |
| Romsey Ice Cream Ltd | Wholesale & retail | 2025 |
| Romsey Kebab House Ltd | Hospitality | 2021 |
| Romsey Perfusion Limited | Health & social care | 2024 |
| Romsey Property Investments Ltd | Real estate | 2018 |
| Romsey Property Management Limited | Real estate | 2022 |
| Romsey Property Services Ltd | Construction | 2016 |
| Romsey Rental Repairs & Refurbishment Ltd | Construction | 2022 |
| Romsey Riverwalk Restoration CIC | Administrative & support | 2017 |
| Romsey Self Storage Ltd | Transport & logistics | 2017 |
| Romsey Storage Ltd | Transport & logistics | 2026 |
| Romsey Structural Engineering Ltd | Construction | 2017 |
| Romsey Tree Surgeons Limited | Agriculture & fishing | 2009 |
| Romsey Trustees Limited | Professional & scientific | 2013 |
| Romsey Van Sales Limited | Wholesale & retail | 2013 |
| Romsey Vehicle Services Limited | Wholesale & retail | 2020 |
| Romtree Limited | Professional & scientific | 2020 |
| Rooido Content Marketing LLP | | 2019 |
| Roots Countryside Management Ltd | Administrative & support | 2025 |
| Roqstar Holdings Ltd | Financial services | 2020 |
| Rosa Estates Limited | Real estate | 2023 |
| Rose Asbestos Ltd | Other services | 2023 |
| Rosebourne Limited | Wholesale & retail | 2014 |
| Rosiben Ltd | Professional & scientific | 2019 |
| Rosy Rentals Ltd | Real estate | 2023 |
| Rothalcourt Limited | Construction | 1973 |
| Roxanne Campbell Ltd | Professional & scientific | 2012 |
| RPE Trading Ltd | Wholesale & retail | 2025 |
| RSD Surgical Limited | Health & social care | 2018 |
| Rsse Properties Limited | Real estate | 2022 |
| RTM Nominee Directors Limited | Extraterritorial | 2006 |
| Ruakhomes Ltd | Real estate | 2025 |
| Rubaka World Federation | Arts & recreation | 2021 |
| Ruka Works Limited | Health & social care | 2024 |
| Ruman Consulting Ltd | Financial services | 2011 |
| Runix Systems Limited | Information & communication | 2025 |
| Rural Pizza Company Limited | Hospitality | 2015 |
| RWJ Consultancy Ltd | Professional & scientific | 2018 |
| RXZ Ltd | Financial services | 2024 |
| RYL John Jupp Ltd | Professional & scientific | 2026 |
| Rymer Commercials Limited | Wholesale & retail | 2002 |
| S & S Ahmed Consulting Ltd | Health & social care | 2025 |
| S & T Engineering Limited | Manufacturing | 2000 |
| S a Investment Properties Limited | Real estate | 2016 |
| S a Roofing and Build Ltd | Construction | 2025 |
| S Bucknole Electrix Ltd | Construction | 2014 |
| S D Perera Limited | Health & social care | 2022 |
| S J Penney Decorating Limited | Construction | 2025 |
| S&B Construction (South) Limited | Construction | 2015 |
| S&T Heating Services Ltd | Construction | 2020 |
| S.O. Wallace Fencing Limited | Construction | 2020 |
| S.R. Walser Limited | Wholesale & retail | 1990 |
| S2 Internet Limited | Information & communication | 2004 |
| S78 Ltd | Manufacturing | 2024 |
| S7T Labs Ltd | Information & communication | 2024 |
| Safe Spaces Group Limited | Information & communication | 2025 |
| Safeguarding & Support Services Limited | Education | 2023 |
| Safetywear Products Ltd | Wholesale & retail | 2014 |
| SAJ Anaesthetics Limited | Health & social care | 2015 |
| Salialco Ltd | Professional & scientific | 2021 |
| Salisbury Car Centre Ltd | Wholesale & retail | 2019 |
| Salv Solutions Limited | Construction | 2009 |
| SAM Barber Shop Ltd | Other services | 2024 |
| SAM Richards Aviation Services Ltd. | Transport & logistics | 2014 |
| Samkad Ltd | Financial services | 2019 |
| Sammy Peach Ltd | Manufacturing | 2020 |
| Sandbox Civils Holdings Ltd | Financial services | 2022 |
| Sandbox Contracting Ltd | Construction | 2019 |
| Sandcrest Medical Limited | Education | 2017 |
| Santley & Ducie Property Management Company | Households | 2003 |
| Sapphire EYE Bidco Limited | Other services | 2023 |
| Sapphire EYE Midco Limited | Other services | 2023 |
| Sapphire EYE Topco Limited | Financial services | 2023 |
| Sapphire Eyecare Limited | Health & social care | 2009 |
| Sapphire Gynae Care Limited | Health & social care | 2024 |
| SAS Lettings Limited | Extraterritorial | 2020 |
| Saufte Ltd | Professional & scientific | 2026 |
| Saulire Procurement Consulting Limited | Professional & scientific | 2017 |
| Savage and Holdsworth Limited | Financial services | 1998 |
| Savages Family Ltd | Wholesale & retail | 2026 |