| R & R Speirs Ltd | Construction | 2024 |
| R Hill Electrical Ltd | Construction | 2011 |
| R Leadon Construction Ltd | Construction | 2011 |
| R&A Brands International Limited | Wholesale & retail | 2021 |
| R.G. Espie & SON Ltd | Construction | 2003 |
| R.J. Walker Enterprises Ltd | Wholesale & retail | 2023 |
| R.W.S. Private Wealth Limited | Professional & scientific | 2025 |
| Racking & Shelving Limited | Manufacturing | 2002 |
| Rafferty Electrical Services Ltd | Construction | 2026 |
| Railway Hill Adventures Ltd | Arts & recreation | 2016 |
| Railway Karting Ltd | Arts & recreation | 2022 |
| Rainey Endowed Limited | Education | 2020 |
| Rainey Street Ltd | Real estate | 2023 |
| Rainvault Ltd | Water & waste | 2010 |
| RAJ Wallace Limited | Health & social care | 2011 |
| Randalstown Hydro Electric Company Ltd | Energy | 1995 |
| Rathepsom Limited | Hospitality | 2024 |
| Rathvada | Construction | 2021 |
| RC Engineering (N.I.) Ltd | Construction | 2012 |
| RC Flat Roofing Systems Ltd | Construction | 2022 |
| Rcds (NI) Ltd | Construction | 2012 |
| RCM Rentals Ltd | Real estate | 2024 |
| Reagh Group Holdings Ltd | Financial services | 2025 |
| Refresh Face Care Clinic Ltd | Health & social care | 2019 |
| Rehon Holdings Limited | Professional & scientific | 2014 |
| Rengineers Service Team Ltd | Manufacturing | 2015 |
| Research Technology Consulting Limited | Information & communication | 2016 |
| Resilient Pharma Ltd | Professional & scientific | 2023 |
| Responsible Solutions Ltd | Professional & scientific | 2023 |
| Retreat Rentals NI Ltd | Hospitality | 2023 |
| Revive Skin and Aesthetics Ltd | Health & social care | 2026 |
| Revolve Refurbishments Ltd | Professional & scientific | 2026 |
| RGM Electrical Ltd | Construction | 2018 |
| Rhob & Co Limited | Professional & scientific | 2021 |
| RIB Farm Services Ltd | Agriculture & fishing | 2018 |
| RIC Property Services Limited | Administrative & support | 2014 |
| Richview Management Company Limited | Real estate | 2002 |
| River Bann Tours Ltd | Transport & logistics | 2019 |
| Riverbrook Property Ltd | Real estate | 2025 |
| Rjbc Holdings Ltd | Financial services | 2025 |
| RJC Holdings (Ireland) Ltd | Financial services | 2025 |
| RJS Property Estates Ltd | Hospitality | 2022 |
| RMM Forestry Ltd | Transport & logistics | 2015 |
| Robert Campbell Haulage Limited | Transport & logistics | 2018 |
| ROC Contracts Group Ltd | Construction | 2020 |
| ROC Contracts Ltd | Construction | 2017 |
| ROC Facilities Management Ltd | Construction | 2019 |
| Rockbrook Decorators Ltd | Construction | 2023 |
| Rockbrook Limited | Professional & scientific | 2019 |
| Ronan Valley Transport Ltd | Wholesale & retail | 2026 |
| Roof Window Specialists Ltd | Construction | 2018 |
| Roof Window Supplies Ltd | Wholesale & retail | 2024 |
| Roofing & Repair Co Ltd | Construction | 2023 |
| Rosa Polonica K9 Ltd | Administrative & support | 2017 |
| Rosegift 71 Limited | Real estate | 2024 |
| Rosegift 73 Limited | Construction | 2024 |
| Rosegift Holdings Limited | Financial services | 2020 |
| Roshure Limited | Wholesale & retail | 2026 |
| Rossclare Investments | Financial services | 2026 |
| Rotel Belfast Ltd | Real estate | 2015 |
| Rotoryze Limited | Professional & scientific | 2024 |
| Rpkelly Limited | Construction | 2025 |
| RR MC Contracts Ltd | Construction | 2020 |
| Ruby's Bar & Night Club Ltd | Hospitality | 2013 |
| Russell Shiels Tyres Ltd | Wholesale & retail | 2006 |
| Rycon Group Ltd | Professional & scientific | 2025 |
| Ryler Limited | Wholesale & retail | 2018 |
| Ryte Group Ltd | Financial services | 2023 |
| Ryte Property Co Ltd | Real estate | 2023 |
| S & S Energy (N.I.) Ltd | Energy | 2016 |
| S Higgins Construction Ltd | Construction | 2015 |
| S Mccrystal Ltd | Construction | 2005 |
| S&L Clinic Limited | Health & social care | 2022 |
| S&P Rentals Ltd | Real estate | 2015 |
| S.T.E.P.S. Mental Health (Suicide.Talking.Education.Prevention.Support.) | Health & social care | 2023 |
| Safetcert Limited | Education | 2015 |
| Safetycert Ltd | Education | 2018 |
| Sakura Art Therapy Ltd | Health & social care | 2017 |
| Savile ROW Company Limited - the | Wholesale & retail | 1989 |
| Savile ROW Direct Limited | Wholesale & retail | 2005 |
| Savile ROW Holding Company Limited - the | Wholesale & retail | 1972 |
| Scalp INK Ltd | Other services | 2026 |
| Scrabo Energy Limited | Energy | 2011 |
| Screen Clinical Limited | Professional & scientific | 2016 |
| Screen Energy Limited | Energy | 2014 |
| Sculpt Pilates Studio NI Ltd | Arts & recreation | 2025 |
| SD Kerr Holdings Ltd | Financial services | 2025 |
| SD Power Limited | Energy | 2017 |
| SDM Motors Ltd | Wholesale & retail | 2026 |
| Seamus Mcpeake & Sons Ltd | Wholesale & retail | 2002 |
| Sean LEE Motors Ltd | Wholesale & retail | 2019 |
| Seanchai Poitin Ltd | Manufacturing | 2025 |
| Seano Breads Limited | Hospitality | 2019 |
| Seaview Construction Limited | Construction | 2023 |
| Seaview Developments Limited | Construction | 1997 |
| Secure Joint Ltd | Construction | 2023 |
| Seed Business Consulting Limited | Wholesale & retail | 2014 |
| Selko Services Ltd | Extraterritorial | 1999 |
| Serenity Hot Tubs Ltd | Wholesale & retail | 2021 |
| Setanta Holdings Limited | Financial services | 2018 |