| Sheerin Electrical (NI) Ltd | Construction | 2021 |
| Shengguigg Ltd | Wholesale & retail | 2025 |
| Sherekan Holdings Limited | Financial services | 2023 |
| Sherex Asset Management Ltd | Real estate | 2026 |
| Sherex Tractors & Tyres Ltd | Wholesale & retail | 2026 |
| Sheridan Bros Agri Ltd | Agriculture & fishing | 2026 |
| Shinelle Care Support Ltd | Health & social care | 2022 |
| Shinerite Solutions Limited | Manufacturing | 2018 |
| Shop Coco Limited | Manufacturing | 2026 |
| Shopmobility Enniskillen | Other services | 2016 |
| Siaky DG Limited | Wholesale & retail | 2025 |
| Signature Scoops Ltd | Manufacturing | 2023 |
| Signs Design Ltd | Professional & scientific | 2018 |
| Silver Dollar Takeaway Limited | Hospitality | 2015 |
| Silverhill House Ltd | Extraterritorial | 2006 |
| Silverhill Maintenance Limited | Administrative & support | 2017 |
| Simpli Automation Ltd | Information & communication | 2024 |
| Simply Fresh Grocery Limited | Wholesale & retail | 2025 |
| Sinead Sheils Consultancy Services Limited | Administrative & support | 2006 |
| SJ Football Services Ltd | Arts & recreation | 2024 |
| Sjpc Enterprises Ltd | Manufacturing | 2026 |
| Skea Construction Ltd | Construction | 2011 |
| Skea EGG Farms Limited | Manufacturing | 1996 |
| Skea Trading Limited | Financial services | 2021 |
| Skeafreight Ltd | Wholesale & retail | 2019 |
| Skeoge Holdings Ltd | Construction | 2020 |
| Skintown Tattoo Studio Ltd | Arts & recreation | 2023 |
| Skip Services Enniskillen Limited | Water & waste | 2003 |
| Skipton Trading Ltd | Real estate | 2011 |
| SL8R Auto Limited | Wholesale & retail | 2026 |
| Slieve Rushen Landowners Limited | Energy | 2024 |
| Slisgarrow Consultants Limited | Administrative & support | 2011 |
| Smart and Creative Solutions Group Technology Ltd | Information & communication | 2022 |
| SMB DAN Developments Limited | Construction | 2015 |
| SMC Services IRL Limited | Other services | 2014 |
| Smcc Consultancy Limited | Professional & scientific | 2025 |
| SMG IT Limited | Information & communication | 2014 |
| Smylie Properties Ltd | Real estate | 2004 |
| Smyth Enterprises Ltd | Wholesale & retail | 2021 |
| Smyth Leslie & Co Limited | Real estate | 2025 |
| Snip Doctors Ltd | Health & social care | 2023 |
| SO Medic Limited | Administrative & support | 2024 |
| Solus Insight Limited | Professional & scientific | 2025 |
| Sonde Music Limited | Information & communication | 2019 |
| Soraghan International Transport Ltd | Transport & logistics | 2016 |
| Soton Properties Limited | Construction | 2013 |
| SOW 2 Reap Trust | Other services | 2006 |
| SP Brady Properties Limited | Real estate | 2020 |
| SP Enniskillen Ltd | Wholesale & retail | 2024 |
| Spa Road (Ballynahinch) Management Ltd | Households | 2023 |
| Spark Enterprises Limited | Real estate | 2011 |
| Specialist Export Solutions Ltd | Professional & scientific | 2021 |
| Speedy Registrations Company Limited | Wholesale & retail | 1998 |
| Sperrin Meats Limited | Wholesale & retail | 2021 |
| Spic N Span Cleaning (NI) Limited | Administrative & support | 2019 |
| Spiceland Enniskillen Limited | Wholesale & retail | 2025 |
| Spinnaker Investments Limited | Real estate | 2005 |
| Springtown Psychological Services Limited | Education | 2021 |
| Sprinkles Delights Ltd | Hospitality | 2023 |
| Square 12 Limited | Real estate | 2012 |
| SRC Jointing Ltd | Construction | 2018 |
| Stacey Cakes Limited | Hospitality | 2026 |
| Stamina Sports Limited | Arts & recreation | 2026 |
| Station Green Enniskillen Ltd | Construction | 2017 |
| Steel Holdco Limited | Professional & scientific | 2013 |
| Stepping Stone Timber Products Limited | Manufacturing | 2005 |
| Sterling Software Productions Limited | Information & communication | 2026 |
| STF Group Ltd | Professional & scientific | 2025 |
| Stlo Holdings (UK) Unlimited | Financial services | 2026 |
| Stoneflow Technologies Ltd | Information & communication | 2025 |
| Stonefort Consultants Ltd | Professional & scientific | 2025 |
| Strapping Investments Limited | Financial services | 2024 |
| Stratus IT Limited | Information & communication | 2023 |
| Stroke Warriors Shop Limited | Wholesale & retail | 2025 |
| Strong Investment Ltd | Real estate | 2026 |
| Struct Steel Engineering Limited | Construction | 2017 |
| Struct Steel Limited | Financial services | 2017 |
| Struct Steel Plant Limited | Administrative & support | 2017 |
| Struserv NI Ltd. | Manufacturing | 2018 |
| Stuart Allen Engineering Ltd | Professional & scientific | 2026 |
| Suanc Limited | Financial services | 2021 |
| Sugar Mill Estates Co Limited | Real estate | 1976 |
| Sugarprojects Ltd | Information & communication | 2014 |
| Sun Holidays Avignon Ltd | Administrative & support | 2018 |
| Sun Holidays Europe Ltd | Administrative & support | 2016 |
| Sun Hols LE Galoubet Ltd | Administrative & support | 2025 |
| Sunnyside Court (E) Management Company Limited | Households | 2003 |
| Sunrise Fast Food Limited | Hospitality | 2022 |
| Sunsetridge Limited | Real estate | 2006 |
| SUP Lough Erne Ltd | Arts & recreation | 2021 |
| Surf Supp Ltd | Wholesale & retail | 2026 |
| SW Financial Holdings Limited | Financial services | 2018 |
| Swan Farm UK Limited | Agriculture & fishing | 2026 |
| Swart Solutions Ltd | Professional & scientific | 2026 |
| Swift & Mccaffrey Funeral Directors Ltd | Other services | 2021 |
| Swifts Retail Holding Ltd | Financial services | 2020 |
| Swifts Supermarkets Ltd | Wholesale & retail | 1999 |
| Swiftsoft Computer Systems (Northern Ireland) Limited | Information & communication | 1976 |
| T Chambers & Sons (Bellanaleck) Limited | Real estate | 2025 |
| T Chambers & Sons (Letterbreen) Limited | Real estate | 2025 |