| Qabas Centre for Research and Development Ltd | Information & communication | 2021 |
| Qandil Food Ltd | Hospitality | 2018 |
| QD Living Limited | Real estate | 2022 |
| Qmsconfig Limited | Professional & scientific | 2023 |
| Qneiform UK Limited | Wholesale & retail | 2024 |
| QOC (Southsea) Holdings Limited | Financial services | 2026 |
| QOC (Southsea) Limited | Hospitality | 2025 |
| Quad Healthcare Solutions Limited | Administrative & support | 2018 |
| Quadcan Ltd | Wholesale & retail | 2016 |
| Quadrant Lettings Ltd | Real estate | 2025 |
| Qualit-Ambulance Ltd | Transport & logistics | 2020 |
| Qualitcare 24-7 Ltd | Health & social care | 2016 |
| Qualitcare Ltd | Administrative & support | 2013 |
| Quality Care Management Limited | Health & social care | 1993 |
| Quality GAS (Portsmouth) Ltd | Construction | 2018 |
| Quanta Dynamics Ltd | Professional & scientific | 2023 |
| Quantifyhr Consultancy Ltd | Administrative & support | 2025 |
| Quantised Media Ltd | Professional & scientific | 2024 |
| Quarrybanx Systems Limited | Professional & scientific | 2025 |
| Quarterdeck Residents Limited | Households | 2004 |
| Quattro Foods Limited | Manufacturing | 2010 |
| Quattro Haulage Limited | Transport & logistics | 2014 |
| Quay Digital Marketing Ltd | Information & communication | 2017 |
| Quay Eyeware Limited | Wholesale & retail | 2016 |
| Quay House (Portsmouth) Limited | Administrative & support | 2010 |
| Quay Lashes Ltd | Other services | 2019 |
| Quaypoint Decorators Limited | Construction | 2014 |
| Quayside Assets Ltd | Real estate | 2025 |
| Quayside Building Supplies Ltd | Wholesale & retail | 2022 |
| Quayside Property Developments Ltd | Real estate | 2024 |
| Quaystone Services Ltd | Construction | 2025 |
| Qude Property Limited | Real estate | 2017 |
| Queens Close RTM Company Ltd | Hospitality | 2012 |
| Queens Hotel (Portsmouth) Limited | Hospitality | 2017 |
| Queens Keep Management Company Limited | Hospitality | 2003 |
| Queensgate 1 Osborne Road Management Company Ltd | Households | 2008 |
| Queensway Property Management Limited | Real estate | 2008 |
| Quick Dynamics Ltd | Information & communication | 2024 |
| Quickcoat Solutions Ltd | Construction | 2025 |
| Quil & Co. Ltd | Administrative & support | 2016 |
| Quintessential Craft Ltd | Wholesale & retail | 2015 |
| Quorium Limited | Construction | 2017 |
| Quote Velocity Ltd | Professional & scientific | 2023 |
| Qvis Lighting & Security Limited | Manufacturing | 2014 |
| Qvis Security Limited | Information & communication | 2012 |
| R & C Technologies Ltd | Information & communication | 2026 |
| R & G Canvas Prints Ltd | Manufacturing | 2026 |
| R & H Consultancy Ltd | Transport & logistics | 2016 |
| R & J Motor Trader Ltd | Wholesale & retail | 2024 |
| R & L Rail Services Limited | Transport & logistics | 2020 |
| R & R Civils (South) Ltd | Construction | 2021 |
| R & S Property Developments Limited | Construction | 2019 |
| R & Z Treat Ltd | Wholesale & retail | 2024 |
| R a Locum Limited | Health & social care | 2005 |
| R B Construction Limited | Wholesale & retail | 2000 |
| R Bonner Services Limited | Construction | 2017 |
| R Burdon Engineering Limited | Construction | 2023 |
| R Carters & Co Ltd | Financial services | 2022 |
| R COX Building and Maintenance Limited | Construction | 2023 |
| R Evans Construction Ltd | Construction | 2017 |
| R Future Developments Ltd | Construction | 2023 |
| R Future Groundworks and Construction Limited | Construction | 2025 |
| R Future Letting Agents Ltd | Real estate | 2025 |
| R J Water Pipes Ltd | Water & waste | 2015 |
| R M Saunders Ltd | Construction | 2025 |
| R P Interiors Ltd | Construction | 2018 |
| R S W Joinery Limited | Administrative & support | 2003 |
| R Sullivan Carpentry Ltd | Construction | 2025 |
| R T Software Limited | Information & communication | 2004 |
| R T Trade Ltd | Wholesale & retail | 2024 |
| R Turner Consultancy Ltd | Information & communication | 2016 |
| R Ways Services Ltd | Other services | 2026 |
| R&B Slow Jams Ltd | Professional & scientific | 2023 |
| R&D Tax Services Southern Ltd | Professional & scientific | 2021 |
| R&J Car Body Repair Ltd | Wholesale & retail | 2024 |
| R&J Signs Limited | Professional & scientific | 2014 |
| R&R Medical Ltd | Health & social care | 2019 |
| R&S Mechanical Ltd | Construction | 2021 |
| R&S Roofing & Cladding (South) Limited | Construction | 2022 |
| R&S Tech Ltd | Manufacturing | 2016 |
| R. and E. Furnishings (Buxton) Limited | Transport & logistics | 1989 |
| R. Rawlins Limited | Construction | 1997 |
| R. Sandilands Limited | Real estate | 1936 |
| R.& W.Holdings Limited | Real estate | 1961 |
| R.H. Insulation Services Holdings Ltd | Financial services | 2024 |
| R.H. Insulation Services Limited | Construction | 1986 |
| R.W.B. & Associates Limited | Administrative & support | 2013 |
| R3 Carpentry Southern Ltd | Construction | 2023 |
| R3 Property Ltd | Households | 2023 |
| R3ENERGISE Ltd | Professional & scientific | 2022 |
| R4C Consultancy Ltd | Professional & scientific | 2024 |
| RA Safety Ltd | Public administration | 2019 |
| RAC Insulation Ltd | Construction | 2021 |
| Rachel Lowe Distribution Limited | Manufacturing | 2017 |
| Rachel Staggs Limited | Professional & scientific | 2013 |
| RAD Heating Solutions Ltd | Professional & scientific | 2016 |
| RAD66 Cars Ltd | Wholesale & retail | 2020 |
| Radh Interiors Ltd | Construction | 2015 |
| Radial Marketing Ltd | Administrative & support | 2008 |
| Radical Darshan Ltd | Education | 2021 |