| RCA Industries Ltd | Arts & recreation | 2023 |
| Red Cottage Enterprises Ltd | Hospitality | 2014 |
| Red Housing Ltd | Real estate | 2025 |
| Red Residential Ltd | Real estate | 2016 |
| Reelspeed Ltd | Wholesale & retail | 2023 |
| REI Services Ltd | Construction | 2005 |
| Rektify Limited | Professional & scientific | 2006 |
| Rent-Right (N.I.) Ltd. | Administrative & support | 2011 |
| Response Network Systems Limited | | 1999 |
| Restore Dromore Ltd | Real estate | 2025 |
| Retail North Ltd | Wholesale & retail | 2018 |
| Revolution Security Ltd | Administrative & support | 2022 |
| RGA Accountants Ltd | Professional & scientific | 2013 |
| Rice Property Holdings Limited | Real estate | 2025 |
| Richard Clarke Painter Decorator Ltd | Construction | 2021 |
| Richtee Limited | Real estate | 2006 |
| Ristretto Limited | Manufacturing | 2005 |
| Rjni Ltd | Real estate | 2021 |
| RL Hold Co Ltd | Financial services | 2025 |
| RLR Estates Ltd | Real estate | 2013 |
| RM Agri Supplies Ltd | Wholesale & retail | 2023 |
| RMA96 Ltd | Real estate | 2025 |
| RMC Property Holdings Ltd | Real estate | 2021 |
| Rmcg Tools Limited | Wholesale & retail | 2015 |
| ROB & AR Limited | Manufacturing | 2021 |
| Robert Martin Fixings Ltd | Wholesale & retail | 2017 |
| Robust Cyber Solutions Ltd | Financial services | 2025 |
| Rock Generator Services Ltd | Manufacturing | 2021 |
| Rockdene Properties Limited | Hospitality | 2021 |
| Rockmount Services Ltd | Transport & logistics | 2015 |
| Roisin MC Avoy Ltd | Professional & scientific | 2024 |
| ROQ Properties Ltd | Real estate | 2021 |
| Rosies Bakes Ltd | Manufacturing | 2021 |
| Ross Electrical & Lighting Ltd | Wholesale & retail | 2019 |
| RSW Estates Ltd | Real estate | 2024 |
| Rubicon (NI) Ltd | Professional & scientific | 2002 |
| RUG Lounge Ltd | Wholesale & retail | 2025 |
| Russell Accountancy Services Ltd | Professional & scientific | 2016 |
| Russell Consultancy Ltd | Professional & scientific | 2017 |
| Rycon Landscapes Limited | Real estate | 2012 |
| S MCB Services Limited | Professional & scientific | 2018 |
| S R Racing Ltd | Arts & recreation | 2021 |
| S&P Building Contracts Ltd | Construction | 2017 |
| S.Henning Transport Limited | Transport & logistics | 2015 |
| S.Kerr & Sons Limited | Real estate | 1955 |
| Safari Grill Ltd | Hospitality | 2018 |
| Safari Steak Burgers Ltd | Extraterritorial | 2015 |
| Safetec Services Limited | Professional & scientific | 2024 |
| Salon SIX (N.I.) Limited | Other services | 2019 |
| Salon Soleil Limited | Other services | 2021 |
| Salt Kitchen Ltd | Hospitality | 2016 |
| Samuel J Esler Ltd | Real estate | 2026 |
| Sands Plant & Utilities Ltd | Construction | 2024 |
| Sasa 1958 Ltd | Other services | 2016 |
| SBP Property Solutions Ltd | Real estate | 2026 |
| Scarva Pottery Supplies Limited | Wholesale & retail | 2024 |
| Scarva Storage & Services Ltd | Administrative & support | 2016 |
| Scarva Street Properties Limited | Real estate | 2013 |
| Sce(Ni) Ltd | Wholesale & retail | 2012 |
| Scissor Sister Banbridge Limited | Other services | 2024 |
| Scott Financial Solutions Ltd | Financial services | 2025 |
| Sculptéclo Ltd | Manufacturing | 2025 |
| Seafin Consultancy Ltd | Professional & scientific | 2025 |
| SEE More Cleaning Services Ltd | Administrative & support | 2019 |
| Selcora Ltd | Wholesale & retail | 2026 |
| Sentry Motors Ltd | Wholesale & retail | 2018 |
| Seven Social Limited | Professional & scientific | 2019 |
| Seven Stars by JMK Limited | Hospitality | 2025 |
| Shahs Kebab Ltd | Hospitality | 2026 |
| Shan 2026 Ltd | Hospitality | 2026 |
| SHAN76 Ltd | Hospitality | 2024 |
| Shanaghan Hill Farm C.I.C. | Education | 2026 |
| Shanrod Farm Ltd | Agriculture & fishing | 2012 |
| Shanroe Limited | Real estate | 2025 |
| Shay-Mac Limited | Arts & recreation | 2012 |
| Shefix Solutions Ltd | Construction | 2021 |
| Shine FM | Information & communication | 2006 |
| Shooter & Co (NI) LLP | | 2014 |
| Shortt Tours Ireland Ltd | Administrative & support | 2023 |
| Show ME the Money (Ireland) Ltd | Arts & recreation | 2025 |
| Silver Ford Developments Ltd | Construction | 2025 |
| Silverwood (Jubilee) Investments Limited | Real estate | 2015 |
| Simply Irresistible Ltd | Hospitality | 2004 |
| SJM Healthcare Solutions Ltd | Financial services | 2023 |
| SK 1 Restaurants Ltd | Hospitality | 2025 |
| Skelton Retail Services Limited | Wholesale & retail | 2018 |
| Skypoint Aerial Ltd | Professional & scientific | 2026 |
| Slaney Estates Ltd | Real estate | 2013 |
| Smart Global Business Ltd. | Professional & scientific | 2022 |
| Smart Global Online Ltd | Professional & scientific | 2016 |
| Smarter Concepts UK & Ireland Ltd | Manufacturing | 2023 |
| Smartsellni Ltd | Real estate | 2025 |
| Smca Property Ltd | Real estate | 2025 |
| Smcv Carpentry Limited | Manufacturing | 2023 |
| Smetric Risk Limited | Financial services | 2012 |
| SMJ Copas Holdings Limited | Financial services | 2025 |
| Smooth Gelato Ltd | Manufacturing | 2024 |
| SMT Agri Diagnostics Limited | Wholesale & retail | 2022 |
| Snack Engineering Ltd | Manufacturing | 2017 |
| Snapp Property Limited | Real estate | 2025 |