| SSS Basandrai Limited | Real estate | 2025 |
| SSS Caterers Ltd | Hospitality | 2023 |
| SSW Logistics Limited | Health & social care | 2011 |
| ST Claire Interiors Limited | Other services | 2017 |
| ST George's Mews Trowbridge LLP | | 2018 |
| ST Martins Court (New Block) Management Limited | Households | 2005 |
| ST. Augustine's Charitable Trust | Administrative & support | 1995 |
| ST. Augustine's Enterprises Limited | Administrative & support | 1993 |
| ST. Peter's Hall Management Limited | Real estate | 2008 |
| Stack the Deck Learning Ltd | Education | 2023 |
| Stag Furniture Ltd | Manufacturing | 2020 |
| Stag Knitwear Company Limited | Wholesale & retail | 1974 |
| Stagwood Enterprises Ltd | Real estate | 2018 |
| Stagwood Limited | Administrative & support | 2012 |
| Stanley Kirk Ltd | Professional & scientific | 2013 |
| Star Butchers Limited | Wholesale & retail | 2017 |
| Star Construction Complex Ltd | Construction | 2020 |
| Star East 3 Limited | Hospitality | 2017 |
| Starfield Court Management Company Limited | Households | 2001 |
| Starlight Buys Ltd | Wholesale & retail | 2024 |
| Starlite Electrics Limited | Arts & recreation | 2006 |
| Starr Doors Limited | Construction | 2020 |
| Starry Eyes CIC | Arts & recreation | 2026 |
| Staverton Marina RTM Company (Trowbridge) Limited | Households | 2009 |
| Steadi Pace Ltd | Information & communication | 2018 |
| Stephen Walkey Ltd | Construction | 2014 |
| Stepping Stones - West Wiltshire Opportunity Group for Children With Special Needs | Education | 1992 |
| Steve Hughes IT Solutions Ltd | Information & communication | 2014 |
| Stockall Precision Sheet Metalwork Limited | Manufacturing | 2004 |
| Stone Circle Development Company Limited | Construction | 2019 |
| Stone Circle Energy Company Limited | Energy | 2020 |
| Stone Circle Holding Company Limited | Financial services | 2019 |
| Stone Circle Housing Company Limited | Real estate | 2019 |
| Stone Circle Supported Housing Company Limited | Real estate | 2023 |
| Stone Developments Holdings Ltd | Real estate | 2023 |
| Stone Developments Wiltshire Limited | Construction | 2014 |
| Stone Homes SW Ltd | Construction | 2020 |
| Stone Vision Consulting Limited | Professional & scientific | 2024 |
| Stones Court Limited | Real estate | 2015 |
| Storm Board LLP | | 2016 |
| Stormhaven Ltd | Wholesale & retail | 2024 |
| STR Retail Ltd | Wholesale & retail | 2022 |
| STR18 Homes Ltd | Real estate | 2026 |
| Straburg Consulting Ltd | Information & communication | 2017 |
| Studio 3 Storage Ltd | Transport & logistics | 2025 |
| Studio 67 Limited | Arts & recreation | 2020 |
| Sugar Hill Limited | Wholesale & retail | 2021 |
| Sumer Probate Limited | Professional & scientific | 2023 |
| Summit Chairs Limited | Manufacturing | 1977 |
| Summit Workspace Limited | Wholesale & retail | 2025 |
| Sunflower Home Support Ltd | Transport & logistics | 2026 |
| Sunny Online Limited | Administrative & support | 2002 |
| Supersonic Delivery & Cleaning Services PVT Ltd Ltd | Transport & logistics | 2025 |
| Surge Ahead Ltd | Administrative & support | 2016 |
| Sussex Uniforms Limited | Wholesale & retail | 2011 |
| Sustainable Image LAB CIC | Professional & scientific | 2023 |
| Suzie Turner X Limited | Wholesale & retail | 2023 |
| Swedish House at Home Limited | Wholesale & retail | 2008 |
| Swft Apparel Limited | Wholesale & retail | 2021 |
| Swindon & Wiltshire Carpets Ltd | Wholesale & retail | 2022 |
| Sword Wealth Management Ltd | Financial services | 2020 |
| SWR Publishing Limited | | 2008 |
| Syndicateaero Ltd | Professional & scientific | 2026 |
| Synergistic Security & Electrical Services Ltd | Professional & scientific | 2012 |
| Sztuczna Polska Ltd | Information & communication | 2025 |
| T 1 Barn Limited | Hospitality | 2017 |
| T Deacon Ltd | Construction | 2004 |
| T Pang Roofing Ltd | Construction | 2026 |
| T.R. Milton Limited | Construction | 1985 |
| Taca Homes Ltd | Real estate | 2025 |
| Tadicare Limited | Health & social care | 2025 |
| Tailor-Made Cafe Ltd | Hospitality | 2024 |
| Talon Consulting (Melksham) Ltd | Manufacturing | 2023 |
| TAO Property Ltd | Real estate | 2021 |
| Tapfuma Limited | Health & social care | 2015 |
| Tapley Furniture Ltd | Manufacturing | 2006 |
| Taproom Arcades Ltd | Manufacturing | 2025 |
| Tarq and Tarq Limited | Manufacturing | 2017 |
| Taste of Great India Ltd | Hospitality | 2020 |
| Taurus Building Ltd | Construction | 2023 |
| Tav's Cars Ltd | Transport & logistics | 2023 |
| Tax Nanny Payroll Limited | Professional & scientific | 2010 |
| Tbdetailing&Autostyling Ltd | Administrative & support | 2025 |
| Tbwc Limited | Information & communication | 2022 |
| TDH Engineering Ltd | Information & communication | 2012 |
| Tdsat Solutions Ltd | Construction | 2022 |
| TEAM4YOUTH Ltd | Health & social care | 2015 |
| Tech and Tyres Mobile Vehicle Services Ltd | Wholesale & retail | 2023 |
| Tech Connect Services Ltd | Construction | 2023 |
| Tech-Unique Services Limited | Professional & scientific | 2012 |
| Technical Expectations Ltd | Professional & scientific | 2013 |
| Technology and Strategy Consulting Limited | Professional & scientific | 2019 |
| Technology Leaders Club Ltd | Administrative & support | 2018 |
| Tecnique Ltd | Professional & scientific | 2010 |
| Telimore Limited | Hospitality | 2016 |
| Tennco Distribution Limited | Other services | 1997 |
| Ternary Services Limited | Professional & scientific | 2024 |
| Tesla-Rides Limited | Transport & logistics | 2026 |
| Teyim Ltd | Administrative & support | 2024 |
| THE ASK Agency Group Ltd | Manufacturing | 2025 |