| Seymour Court Management Company (Trowbridge) Ltd | Real estate | 2017 |
| Sezam Ltd | Manufacturing | 2018 |
| SFJ Systems Limited | Information & communication | 1995 |
| SG Design and Build Ltd | Construction | 2021 |
| SH Property Ltd | Real estate | 2023 |
| Shakuntla Devi Prithi Chand Limited | Hospitality | 2018 |
| Shampu Ltd | Health & social care | 2026 |
| Shamrock Park Farm Limited | Agriculture & fishing | 2014 |
| Shaun Kent Electrical Ltd | Construction | 2021 |
| Shawn Carr Limited | Construction | 2004 |
| Shearson Developments Ltd | Construction | 2025 |
| Sheepsulation Ltd | Wholesale & retail | 2020 |
| Shelled Limited | Real estate | 2024 |
| Shepherd Ellis Accounts and Consultancy Ltd | Professional & scientific | 2018 |
| Shepherds Retreat Farm Ltd | Agriculture & fishing | 2026 |
| Sheppard Safety Engineering Consultancy Ltd | Professional & scientific | 2020 |
| Sheridan Decorating Ltd | Construction | 2026 |
| Shermans & Co Limited | Construction | 2011 |
| Shippa Ltd | Financial services | 2026 |
| Shire Consultants Limited | Administrative & support | 2017 |
| Shodann Limited | Information & communication | 2012 |
| Shov Limited | Health & social care | 2020 |
| Sidhan Food Services Ltd | Hospitality | 2023 |
| Silcoa Limited | Construction | 2014 |
| Silica Developments Ltd | Construction | 2011 |
| Silk Money Limited | Financial services | 2014 |
| Simax Scaffolding Limited | Construction | 2017 |
| Simon Cole Abs/Ebs Specialist Limited | Wholesale & retail | 2016 |
| Simon Shanks Tour Golf Coaching Limited | Education | 2017 |
| Simtrans Ltd | Transport & logistics | 2025 |
| SIN Taxi Limited | Transport & logistics | 2024 |
| Sinceris Atelier Ltd | Professional & scientific | 2026 |
| Sing ME Happy Birthday Ltd | Wholesale & retail | 2020 |
| Sirox Limited | Hospitality | 2009 |
| Sisters of Skinn Limited | Other services | 2025 |
| Sjbrake Properties Limited | Real estate | 2016 |
| SJC Consultancy (UK) Limited | Information & communication | 2013 |
| SJH Improvements Limited | Construction | 2026 |
| Skills Direct Ltd | Administrative & support | 2007 |
| Skip 2 IT Limited | Water & waste | 2021 |
| Skips 4 U Ltd | Water & waste | 2020 |
| Skwizz Ltd | Information & communication | 2024 |
| Skye Wind Limited | Manufacturing | 2025 |
| Skyforge Limited | Wholesale & retail | 2023 |
| Skysure Investments Ltd | Hospitality | 2023 |
| Slayline Drips Ltd | Health & social care | 2025 |
| SLK Bars Ltd | Hospitality | 2025 |
| Slts (Southwest) Ltd | Construction | 2015 |
| Smallbrook Court (Staverton) Management Company Ltd | Households | 2015 |
| Smart Letting Property Management Ltd | Real estate | 2003 |
| Smart Moves Property Rentals Limited | Real estate | 2023 |
| Smartdesignershopper Ltd | Wholesale & retail | 2015 |
| Smartohmic Ltd | Manufacturing | 2021 |
| Smiles Marketing Ltd | Professional & scientific | 2025 |
| Smith and Arbor Ltd | Administrative & support | 2020 |
| SMP Artizan Ltd | Professional & scientific | 2013 |
| Smyan Food Services Ltd | Hospitality | 2023 |
| Snappy Catering Limited | Hospitality | 2013 |
| Snaya Food Services Ltd | Hospitality | 2023 |
| Snaya&Sidhan Limited | Hospitality | 2019 |
| Snnzozdmr Ltd | Wholesale & retail | 2025 |
| Snuggy Hoods Limited | Manufacturing | 2002 |
| SO Smug Ltd | Real estate | 2025 |
| So-Cleaning Service Ltd | Administrative & support | 2026 |
| Software Safety Limited | Information & communication | 2015 |
| Solide Online Store Ltd | Wholesale & retail | 2025 |
| Solridout Construction Ltd | Construction | 2021 |
| Soma Limited | Health & social care | 2024 |
| Soma Supplements Ltd | Manufacturing | 2025 |
| SON of Jesse Ltd | Information & communication | 2022 |
| South West Business Advisors Ltd | Professional & scientific | 2005 |
| South West Care Services Ltd | Public administration | 2024 |
| South West Drone Media Ltd | Information & communication | 2025 |
| South West Project Management Limited | Professional & scientific | 2004 |
| South West Property Surveys Ltd | Households | 2024 |
| Southdown Developments Limited | Construction | 2016 |
| Southfield Apartments Management Company Limited | Real estate | 2001 |
| Southwell-Sander Consulting Limited | Professional & scientific | 2017 |
| Southwest Scaffolding Sheeting Ltd | Construction | 2024 |
| Southwick 60'S Ltd | Wholesale & retail | 2021 |
| Southwick Allotment Association Limited | Other services | 2014 |
| Southwick Car Centre Limited | Wholesale & retail | 2004 |
| Southwick Tractor Co. Limited | Wholesale & retail | 1984 |
| Southwick Window Warehouse Limited | Wholesale & retail | 2012 |
| Sowhat Security Ltd | Information & communication | 2023 |
| Spba Property Ltd | Real estate | 2024 |
| Speich Limited | Professional & scientific | 2023 |
| Spencer Moulton BC Limited | Arts & recreation | 2022 |
| Sphere Management Consultancy Limited | Information & communication | 2011 |
| Spire Digital Solutions Limited | Wholesale & retail | 2003 |
| Sporting Family Change Enterprises Limited | Administrative & support | 2020 |
| Sportsbug Limited | Wholesale & retail | 2011 |
| Sportsbug Trowbridge Ltd | Real estate | 2017 |
| Sportswear International Limited | Wholesale & retail | 1977 |
| Springleaze Trading Company Limited | Agriculture & fishing | 1996 |
| Sprint Manufacturing Limited | Wholesale & retail | 2016 |
| SPS Bar Ltd | Hospitality | 2024 |
| SPS Properties Investment Ltd | Real estate | 2023 |
| Sree RAM Food Ltd | Hospitality | 2021 |
| Sreg Products Limited | Manufacturing | 2020 |