| Rock Shelving Limited | Construction | 2023 |
| Rockall Realty Ltd | Real estate | 2023 |
| ROD Car Sales Limited | Wholesale & retail | 2023 |
| ROE Consultancy North West Ltd | Professional & scientific | 2013 |
| ROE Plant Hire Ltd | Construction | 2022 |
| Roll Innovation Ltd | Professional & scientific | 2016 |
| Rolling Hills Investments Ltd | Real estate | 2014 |
| ROM Partitions Ltd | Construction | 2020 |
| Romeos (Derry) Limited | Hospitality | 2019 |
| Rongdirect Limited | Wholesale & retail | 2025 |
| Rooh VCO Ltd | Wholesale & retail | 2023 |
| Rooroo Ltd | Hospitality | 2016 |
| Rory Mclaughlin Education Services Limited | Education | 2017 |
| Rosborough Holdings Limited | Wholesale & retail | 2024 |
| Rosemount Studios Ltd | Manufacturing | 2025 |
| Rosetta Radix Ltd | Health & social care | 2023 |
| Rosewood Grove Estates Co Ltd | Real estate | 2025 |
| Rosslyn Development Ltd | Construction | 2011 |
| Rough Brothers Brewing Limited | Manufacturing | 2018 |
| Rowan DEW Ltd | Health & social care | 2024 |
| Rowangrove Ltd | Professional & scientific | 2023 |
| Roxcam Limited | Real estate | 2025 |
| Roxy Construction Ltd | Construction | 2015 |
| RPB Mobiles Limited | Wholesale & retail | 2006 |
| RPM Lifting Solutions Ltd | Manufacturing | 2025 |
| Rrlb Entertainment Holdings Ltd | Financial services | 2025 |
| RS Beauty Ltd | Other services | 2018 |
| RS Crash Solutions Ltd | Other services | 2021 |
| RS Moore Limited | Professional & scientific | 2025 |
| RSR Contracts Limited | Construction | 2014 |
| RT179 Ltd | Real estate | 2022 |
| RTB Fitness Limited | Arts & recreation | 2024 |
| RTF Properties Ltd | Real estate | 2021 |
| Rthomas Ltd | Professional & scientific | 2023 |
| Rtindre Erway Ltd | Wholesale & retail | 2024 |
| RTL Painting Ltd | Construction | 2024 |
| Rubbertec International Limited | Manufacturing | 2006 |
| Ruben Fabrications Ltd | Construction | 2022 |
| Rumex Trading Limited | Construction | 2005 |
| Rushfield Residential Ltd | Households | 2020 |
| Russell Tiles Ltd | Wholesale & retail | 2010 |
| Russell's (Frozen Foods) Limited | Real estate | 1977 |
| Ruvigny (Northern Ireland) Ltd | Construction | 2001 |
| Rvco Holdings Limited | Financial services | 2024 |
| RW Energy Ltd | Professional & scientific | 2022 |
| Rwcam Ltd | Real estate | 2025 |
| Rwdkc Holdings Ltd | Hospitality | 2022 |
| RWG Fencing Ltd | Construction | 2020 |
| Ryan Mullin Property Solutions Limited | Real estate | 2021 |
| Ryan Ventilation Services Ltd | Manufacturing | 2012 |
| Ryan's Retail Ltd | Wholesale & retail | 2016 |
| Ryandohertymechanical Limited | Construction | 2025 |
| S & E Mclaughlin Limited | Agriculture & fishing | 2012 |
| S & P Ceilings & Partitions Limited | Construction | 2025 |
| S & T Chip Limited | Energy | 2015 |
| S Boyle Civils (NI) Limited | Construction | 2023 |
| S O'Kane Formwork Limited | Construction | 2020 |
| S R Seafood Ltd | Agriculture & fishing | 2015 |
| S&K Properties Ltd | Real estate | 2022 |
| S. & P.S. Kular Limited | Real estate | 1987 |
| S.I.E. Ltd | Administrative & support | 2001 |
| S.M.Devine Homes (NI) Ltd | Construction | 2013 |
| S2 EDC Limited | Professional & scientific | 2022 |
| S3 Alliance Limited | Manufacturing | 2007 |
| S3 Holdings Limited | Financial services | 2021 |
| Sabhal Ltd | Real estate | 2024 |
| Saeso Technologies Ltd | Information & communication | 2025 |
| Safe D Training Limited | Education | 2024 |
| Safe Flue Solutions Limited | Administrative & support | 2021 |
| Safeflow Traffic Management Ltd | Construction | 2024 |
| Safeguard Technical Textiles (NI) Ltd | Wholesale & retail | 2011 |
| Safety Protects N.I. Ltd | Education | 2025 |
| Sailbywire Limited | Manufacturing | 2025 |
| Sailing North Ltd | Other services | 2018 |
| Sales Centric Ltd | Professional & scientific | 2020 |
| Salumeria Mariuccia Ltd | Hospitality | 2023 |
| SAN Big Bites Ltd | Hospitality | 2020 |
| Sandale Park Management Company Limited | Households | 2002 |
| Sandino's Limited | Hospitality | 2003 |
| Sandville Court Management Company Limited | Households | 2016 |
| Sanfran Property Limited | Real estate | 2024 |
| Sang Nails & Spa Ltd | Other services | 2023 |
| Sartep Properties Ltd | Real estate | 2024 |
| Saru Business Consultancy Services Ltd | Professional & scientific | 2024 |
| Saru Homes Limited | Financial services | 2025 |
| Satori Accounting Limited | Professional & scientific | 2012 |
| Sawel Construction Ltd | Professional & scientific | 2005 |
| Saxon Ansgar Ltd | Professional & scientific | 2023 |
| Sbcr Trading Limited | Wholesale & retail | 2018 |
| Sbmac Investments Ltd | Financial services | 2024 |
| SC Cloud Consulting Limited | Information & communication | 2019 |
| SC Cloud Holdings Limited | Financial services | 2025 |
| SC Cloud Limited | Professional & scientific | 2025 |
| SC Enterprise Solutions Ltd | Information & communication | 2021 |
| SCF Drylining Ltd | Construction | 2020 |
| Schos Limited | Hospitality | 2012 |
| Scinect Discovery Ltd | Professional & scientific | 2024 |
| Scoltock Enterprises Ltd | Wholesale & retail | 2024 |
| Scoresby Trading Limited | Wholesale & retail | 2020 |
| Scott Group Construction Limited | Construction | 2017 |