| Roisin Enterprise Limited | Hospitality | 2014 |
| Roman Gardens Ltd | Administrative & support | 2026 |
| Roop Logistics Ltd | Transport & logistics | 2026 |
| Rose Anderson Limited | Professional & scientific | 2018 |
| Rose Elite Medical Ltd | Health & social care | 2025 |
| Rossengineersuk Ltd | Manufacturing | 2025 |
| Routine Properties Ltd. | Real estate | 2022 |
| Roxys Takeaway Limited | Hospitality | 2024 |
| Royaii Group Ltd | Manufacturing | 2025 |
| RTS Minibuses Limited | Transport & logistics | 2006 |
| Rubber Roofs Limited | Construction | 2013 |
| Ruby Letting Ltd | Real estate | 2013 |
| Rygbiinnovation CYF. | Professional & scientific | 2013 |
| S M Autos Rhyl Limited | Wholesale & retail | 2003 |
| S M W Crane & Hoist Ltd. | Professional & scientific | 2010 |
| S R Beech & Sons Contracting Ltd | Agriculture & fishing | 2012 |
| S. R. Beech and Sons LLP | | 2012 |
| SA Competitions Ltd | Arts & recreation | 2026 |
| Saar Management Advisory Limited | Professional & scientific | 2016 |
| SAC Property Investments Limited | Real estate | 2015 |
| Safe Haven Security Ltd | Administrative & support | 2026 |
| Sage Cleaning Services Ltd | Administrative & support | 2026 |
| Saint Maria Ltd | Real estate | 2024 |
| Salapura Holdings Ltd | Wholesale & retail | 2021 |
| Samco Industrial Merchants Limited | Wholesale & retail | 2006 |
| Samco Products Limited | Wholesale & retail | 1975 |
| Sandra & IAN Melyd Ltd | Hospitality | 2025 |
| Santos Delivery Limited | Other services | 2025 |
| Sapphire Financial Solutions Ltd | Financial services | 2011 |
| Sarchrias Limited | Other services | 2004 |
| SE Hall Homes Ltd | Real estate | 2021 |
| Seaside Accessories Limited | Wholesale & retail | 2025 |
| Secure Security Operations Ltd | Administrative & support | 2025 |
| Seif IT Ltd | Hospitality | 2025 |
| Serene Surprises Ltd | Wholesale & retail | 2015 |
| Sethi Group Limited | Real estate | 2019 |
| Seven Ways Environmental Services Limited | Water & waste | 2001 |
| Shoreline Removals Limited | Transport & logistics | 2012 |
| Shushoo Limited | Wholesale & retail | 2020 |
| Sian Jones Translation Ltd | Other services | 2020 |
| Simply Fish & Chips JM Ltd | Hospitality | 2025 |
| Simply Logo Limited | Manufacturing | 2005 |
| Simply On-Site Solutions Limited | Extraterritorial | 2010 |
| Sit.Stay.Play Ltd | Arts & recreation | 2025 |
| SJK Training Ltd | Education | 2023 |
| Skellys Ice Cream Van Conversions Limited | Wholesale & retail | 2025 |
| Sky Care North Wales Ltd | Health & social care | 2022 |
| Skyline Care Ltd | Health & social care | 2017 |
| Skyline Care Property Ltd | Health & social care | 2018 |
| Slavov Aesthetics Ltd | Financial services | 2017 |
| Sleepy Kitten Ltd | Wholesale & retail | 2017 |
| SLJ Photography Ltd | Professional & scientific | 2020 |
| Smiths Plastering Contractors & Multi - Trade Ltd | Construction | 2025 |
| Snow Foods (Manufacturing) Limited | Manufacturing | 2011 |
| Snow Property Limited | Extraterritorial | 2014 |
| Snowdonia Cheese Company Ltd | Manufacturing | 2001 |
| Snowdonia Export Limited | Wholesale & retail | 2014 |
| Snowdonia Food Company Ltd | Professional & scientific | 2001 |
| Snowdonia Retail Limited | Extraterritorial | 2014 |
| Sohail Properties Holding Limited | Real estate | 2023 |
| Sohail Properties Limited | Construction | 2020 |
| Solace Wake Ltd | Wholesale & retail | 2026 |
| Solar TEK NW Ltd | Construction | 2025 |
| Soldiers OFF the Street | Health & social care | 2009 |
| Splashpoint Apartments (Rhyl) RTM Company Limited | Real estate | 2013 |
| Spot on Cafe Limited | Hospitality | 2018 |
| Spuds and Puds Ltd | Hospitality | 2023 |
| SSJ Martial Arts Limited | Arts & recreation | 2024 |
| SSR Cleaning Services Ltd | Administrative & support | 2022 |
| SSR Exterior Cleaning Limited | Administrative & support | 2025 |
| SSR Property Solutions Limited | Real estate | 2025 |
| SSR Window Cleaning Limited | Administrative & support | 2025 |
| ST Radiology Limited | Health & social care | 2023 |
| Standard Lift (Rhyl) Limited | Other services | 1979 |
| Stanleys Mini Travel Limited | Transport & logistics | 2011 |
| Stanton Powell Group Ltd | Real estate | 2023 |
| Star Barbers Bodfor Ltd | Other services | 2024 |
| Star MOT & Autos Limited | Wholesale & retail | 2025 |
| Starlight North Wales Ltd | Health & social care | 2016 |
| Static Sales Hub Ltd | Professional & scientific | 2025 |
| Stead Medical Ltd | Public administration | 2025 |
| Steakhouse ST. Thomas Ltd | Extraterritorial | 2018 |
| Sterling Global Property Management Ltd | Construction | 2025 |
| Stevens Group Ltd | Wholesale & retail | 2021 |
| Stonebeach Developments Limited | Real estate | 1985 |
| Stonedark Ltd | Wholesale & retail | 2025 |
| Street Peri Peri& Grill Limited | Hospitality | 2025 |
| Structures (W) CYF | Construction | 2018 |
| Stuff & Nonsense Ltd | Information & communication | 1998 |
| Sumang Food Stuff Ltd | Wholesale & retail | 2023 |
| Summerhouse OUT of School Club Ltd. | Education | 2019 |
| Summit Leads Ltd | Professional & scientific | 2026 |
| Sun City Rhyl 168 Ltd | Hospitality | 2026 |
| Sun Network Limited | Wholesale & retail | 2008 |
| Superior Driveways and Roofing Ltd | Construction | 2025 |
| Suruc 63 Limited | Hospitality | 2025 |
| SWA Properties Ltd | Real estate | 2024 |
| Swiftpath Direct Ltd | Transport & logistics | 2025 |
| SY 1 Food Ltd | Hospitality | 2026 |
| Sylavee UK Ltd | Wholesale & retail | 2026 |