| Rocc Property Holdings Ltd | Real estate | 2026 |
| Rocklion Ltd | Real estate | 2023 |
| Rockstown Farm Ltd | Agriculture & fishing | 2026 |
| Rocktown Trading Limited | Wholesale & retail | 2009 |
| Rodgers Music Company Ltd | Information & communication | 2016 |
| Rogers Product Design Ltd | Information & communication | 2026 |
| Rolby Properties Ltd | Real estate | 2023 |
| Romi Engineering Services Ltd | Professional & scientific | 2024 |
| Roosevelt Property Investments Limited | Real estate | 2016 |
| ROR Catering Ltd | Hospitality | 2026 |
| Rosbeg Cottages Limited | Hospitality | 2015 |
| Ross Court Limited | Hospitality | 2024 |
| Ross Nethery Ltd | Wholesale & retail | 2022 |
| Rosvey Joinery & Building Ltd | Construction | 2018 |
| Rover Coffee House Ltd | Manufacturing | 2023 |
| Rowandale Farm Ltd | Manufacturing | 2022 |
| Royale DRY Cleaning Limited | Other services | 2013 |
| Roycroft Management Company Limited | Households | 2020 |
| RPE Radiation Services Ltd | Professional & scientific | 2020 |
| RPM UN Ltd | Construction | 2009 |
| RPS Restaurants PVT Limited | Hospitality | 2016 |
| RR Technical Services Ltd | Manufacturing | 2022 |
| RS Race Prep and Fabrication Ltd | Manufacturing | 2022 |
| RS Road Freight Services Limited | Transport & logistics | 2019 |
| Rtse Ltd | Manufacturing | 2024 |
| Ruairi Connaughton Holdings Ltd | Financial services | 2017 |
| Rubelle Real Estate Ltd | Real estate | 2021 |
| Ruby Hill Caravan Park Ltd | Hospitality | 2025 |
| Ruby Star NI Ltd | Arts & recreation | 2024 |
| Rvfam Limited | Professional & scientific | 2024 |
| Rwhb Industries Ltd | Information & communication | 2024 |
| Ryland Care Ltd | Administrative & support | 2022 |
| Rylandale Farm Limited | Agriculture & fishing | 2019 |
| Rylands Nursing Home Limited | Health & social care | 2006 |
| S & E Builders (Northern Ireland) Ltd | | 2006 |
| S & L Contracts Ltd | Construction | 2016 |
| S Blaney Estates Ltd | Financial services | 2025 |
| S Dooey & Co Limited | Construction | 1999 |
| S G Medical Services Limited | Health & social care | 2026 |
| S Graham Electrical Limited | Construction | 2014 |
| S J M Supermarkets Limited | Information & communication | 2001 |
| S Mcafee & SON | Wholesale & retail | 2022 |
| S Watson Consultancy Ltd | Professional & scientific | 2022 |
| S&E Project Management & Construction Consultancy NI Ltd | Professional & scientific | 2025 |
| S. Blaney Construction Limited | Other services | 2005 |
| S.C. Properties (N.I.) Limited | Real estate | 2018 |
| S.E. Mckay & SON Limited | Wholesale & retail | 2005 |
| S.H. Coleman (Glarryford) Limited | Manufacturing | 1980 |
| SA House Rental Ltd | Real estate | 2025 |
| Sabre FX Signals Limited | Information & communication | 2019 |
| Saffron Solutions Consultancy Ltd | Professional & scientific | 2025 |
| Samantha & Lynsay Limited | Other services | 2020 |
| Samaritans of Ballymena | Other services | 2017 |
| Samuel Getty Limited | Wholesale & retail | 1966 |
| SAP Blinds & Shutters Ltd | Construction | 2022 |
| Sarcon (NO. 376) Limited | Real estate | 2014 |
| Sarcon (NO.213) Limited | Construction | 2006 |
| SB Contracts Ltd | Construction | 2024 |
| SB Fitness Ltd | Arts & recreation | 2015 |
| SC Joinery & Shopfitting Contracts Limited | Construction | 2016 |
| Scanbox (UK & Ireland) Ltd | Manufacturing | 2014 |
| Scanbox Acquisitions Limited | Financial services | 2024 |
| Scholar Healthcare Ltd | Public administration | 2024 |
| Scoops and Shakes (NI) Limited | Wholesale & retail | 2025 |
| Scott Homes (NI) Limited | Construction | 2004 |
| SD Plumbing + Heating Contracts Limited | Construction | 2018 |
| Sean Kyle Properties (Ballymena) Limited | Real estate | 1986 |
| Sean Mcpeake & SON Ltd | Transport & logistics | 2011 |
| Sehen Ltd | Professional & scientific | 2017 |
| Selas.Selas Ltd | Manufacturing | 2018 |
| Selonur Cleaning Ltd | Administrative & support | 2025 |
| Semac Holdings Ltd | Professional & scientific | 2020 |
| Sentry Hollow Management Ltd | Households | 2006 |
| September Developments Limited | Real estate | 2005 |
| Serenity Luxury Hot TUB Hire Ltd | Administrative & support | 2021 |
| Sessia Acquisitions Ltd | Professional & scientific | 2021 |
| Sessia Holdings Ltd | Financial services | 2021 |
| Sessia Ltd | Wholesale & retail | 2008 |
| Seventeen Lions Properties | Real estate | 1977 |
| Sfxni Limited | Professional & scientific | 2017 |
| Shane FM Ltd | Construction | 2023 |
| Shane Mechanical (London) Ltd | Construction | 2018 |
| Shauna Global Trading Limited | Wholesale & retail | 2023 |
| Shaunella Holdings Limited | Construction | 2025 |
| Shaw Power Generation Ltd | Energy | 2024 |
| SHB Commerce Ltd | Wholesale & retail | 2025 |
| Shell Hill Ltd | Construction | 2023 |
| Shelton Meadow (NO.2) Management Limited | Households | 2022 |
| Shift a Yoke Ltd | Transport & logistics | 2025 |
| Shirt & Mcerlain Roofing Ltd | Construction | 2023 |
| Shock Tactics Suspension Services Limited | Wholesale & retail | 2015 |
| Shopmobility Ballymena Limited | Professional & scientific | 1999 |
| Shph Ltd | Other services | 2019 |
| Sigma Secure Solutions Ltd | Administrative & support | 2019 |
| Signature Wraps'N'Maps Ltd | Wholesale & retail | 2020 |
| Silent Pilot Ltd | Professional & scientific | 2026 |
| Silent Valley Farms Ltd | Agriculture & fishing | 2024 |
| Silver Stream Fisheries Limited | Agriculture & fishing | 1969 |
| Simply Seaweed Limited | Hospitality | 2023 |
| Simpson Bros Consultancy Ltd | Professional & scientific | 2025 |