| Screwfix Direct Limited | Wholesale & retail | 1995 |
| Screwfix Spares Limited | Wholesale & retail | 1998 |
| Scruffs Workwear Ltd | Wholesale & retail | 2023 |
| Seaborough Manor Limited | Agriculture & fishing | 1959 |
| Seahorse Futures Ltd | Professional & scientific | 2025 |
| Sealteam Limited | Real estate | 2018 |
| Searches - Direct Ltd | Administrative & support | 2024 |
| Secret to Beauty Ltd | Other services | 2021 |
| Secure Holdings (Yeovil) Limited | Real estate | 2016 |
| Securearm Technology Ltd | Information & communication | 2016 |
| Security & Electrical Services (Yeovil) Limited | Wholesale & retail | 2002 |
| Security (Southwest) Ltd | Administrative & support | 2024 |
| Security Solutions and Services Ltd | Administrative & support | 2026 |
| Sedgesmith Limited | Professional & scientific | 2021 |
| Seepex UK Limited | Professional & scientific | 1981 |
| Seika Group Ltd | Information & communication | 2026 |
| SEM Change Ltd | Professional & scientific | 2026 |
| Senior Farming Limited | Agriculture & fishing | 2014 |
| Senyah Limited | Construction | 2007 |
| Sequel Agency Ltd | Information & communication | 2019 |
| Serfino Ltd | Professional & scientific | 2024 |
| Serfino Services Ltd | Information & communication | 2026 |
| SEVINDI68 Ltd | Hospitality | 2024 |
| SFD Ltd | Extraterritorial | 2006 |
| SGC LC Limited | Professional & scientific | 2025 |
| Shadow and Spice Smash Burgers Ltd | Hospitality | 2026 |
| Shahs (UK) Limited | Real estate | 2013 |
| Shane Aherne Hair Studio LLP | | 2021 |
| Shapesmiths Fitness Ltd | Arts & recreation | 2015 |
| Sharelead Limited | Wholesale & retail | 2008 |
| Shark - Gutter and Window Cleaning Ltd | Administrative & support | 2020 |
| Shearbarn Holiday Park Limited | Hospitality | 2013 |
| Shelden Glass Ltd | Manufacturing | 2025 |
| Shellard Electrical Ltd | Construction | 2023 |
| Sheq Services Limited | Administrative & support | 2012 |
| Sherborne Castle Country Fair | Arts & recreation | 2003 |
| Sherborne Developments LLP | | 2016 |
| Sherborne House Enterprises Limited | Hospitality | 2021 |
| Sherborne House Trust 2018 | Real estate | 2018 |
| Sherborne Mortgages Limited | Administrative & support | 2016 |
| Shieldunion Official CIC | Information & communication | 2025 |
| Shilcock Holdings Limited | Financial services | 2026 |
| Shine Line Support Solutions Ltd | Administrative & support | 2025 |
| Ship and Sherry Limited | Real estate | 1932 |
| Shipley Limited | Professional & scientific | 1997 |
| Shlm Limited | Information & communication | 2025 |
| Shoetrees Limited | Other services | 2005 |
| Signal Coding Limited | Information & communication | 2026 |
| Signature Group Events Ltd | Professional & scientific | 2023 |
| Significa Heritage Consulting Limited | Professional & scientific | 2025 |
| Silladar Estate Limited | Agriculture & fishing | 1986 |
| Silly Sausage Grill Ltd | Hospitality | 2023 |
| Silver FOX Software Ltd | Information & communication | 2020 |
| Silverline Tools Limited | Professional & scientific | 2004 |
| Silverstone Parks Limited | Real estate | 2018 |
| Silvester Property Holdings Ltd | Real estate | 2026 |
| Simon Helm Artist Limited | Arts & recreation | 2022 |
| Simon Says Retail Ltd | Wholesale & retail | 2024 |
| Simonite Ltd | Professional & scientific | 2022 |
| Simosvio Ltd | Wholesale & retail | 2022 |
| Simply Racing Limited | Extraterritorial | 2017 |
| Simply Serve Limited | Administrative & support | 2017 |
| Simshack Ltd | Information & communication | 2022 |
| Sintasworld Limited | Professional & scientific | 2015 |
| Sister by Studio Ashby Ltd | Wholesale & retail | 2020 |
| SIT and Strengthen Ltd | Arts & recreation | 2024 |
| Site Diesel Limited | Information & communication | 2014 |
| Sitruna Logistics Ltd | Transport & logistics | 2020 |
| Sizwe Enterprise Ltd | Health & social care | 2018 |
| SJB Group Holdings Ltd | Financial services | 2024 |
| Sjmc Consultancy Services Ltd | Information & communication | 2022 |
| SJO and PLO Consultancy Ltd | Administrative & support | 2013 |
| Skcm Property Ltd | Real estate | 2026 |
| Skirton Lawrence Ltd | Real estate | 2020 |
| Skool Beanz CIC | Education | 2021 |
| Skyward Digital Limited | Information & communication | 2017 |
| Skyway Enterprices 4U Ltd | Transport & logistics | 2023 |
| SL Publications Ltd | Manufacturing | 2023 |
| Slade Parry Limited | Professional & scientific | 2005 |
| Slades Developments Ltd | Construction | 2025 |
| Slades Property Holdings Ltd | Real estate | 2022 |
| Slide Systems Limited | Wholesale & retail | 2013 |
| SLK CC Limited | Manufacturing | 2005 |
| Smallfield Electrical Services Limited | Construction | 2015 |
| Smart Home Addict Ltd | Information & communication | 2021 |
| Smart Tech Engineering Ltd | Manufacturing | 2017 |
| Smartrium UK Ltd | Administrative & support | 2024 |
| Smile Coffee Limited | Financial services | 1993 |
| Smiling Rays Ltd | Construction | 2017 |
| Smith & Smith Holdings Limited | Real estate | 2021 |
| Smith Carpentry and Construction Limited | Construction | 2012 |
| Smiths Kitchen Dorset Limited | Hospitality | 2026 |
| SML Lettings Limited | Hospitality | 2019 |
| Snell Print Limited | Manufacturing | 2003 |
| SO Pampered Ltd | Health & social care | 2018 |
| Soab Ltd | Professional & scientific | 2025 |
| Social Media Management Ltd | Professional & scientific | 2022 |
| Sokal Enterprises Limited | Real estate | 2014 |
| Solarhydrogenfuel.Co.Uk Limited | Extraterritorial | 2009 |
| Solomon Home Improvement Ltd | Construction | 2024 |