| Sherborne Optical Limited | Wholesale & retail | 2017 |
| Sherborne Retail Limited | Wholesale & retail | 2024 |
| Sherborne School (Leisure) Limited | Arts & recreation | 2001 |
| Sherborne School (Overseas Education) Limited | Administrative & support | 2009 |
| Sherborne School (Overseas Trading) Limited | Administrative & support | 2009 |
| Sherborne School (Trading) Limited | Other services | 1992 |
| Sherborne Schools Group | Education | 2000 |
| Sherborne Schools Worldwide Limited | Education | 2017 |
| Sherborne Sports and Leisure Limited | Arts & recreation | 2006 |
| Sherborne Stone Limited | Mining & quarrying | 2002 |
| Sherborne Storage Limited | Real estate | 2013 |
| Sherborne Tennis Club Limited | Arts & recreation | 2024 |
| Sherborne Turf Limited | Wholesale & retail | 1997 |
| Sherborne Utilities Ltd | Construction | 2011 |
| Sherborne Web Design Ltd | Information & communication | 2015 |
| Sicotronic (UK) Ltd | Information & communication | 2019 |
| Sidbury LVA LLP | | 2014 |
| Sidford LVA LLP | | 2022 |
| Sierra Sounds Ltd | Administrative & support | 2024 |
| Sigma (Accounting Tax & Business Advice) LLP | | 2004 |
| Sikder Trading Ltd | Hospitality | 2019 |
| Silbury Accountants Limited | Professional & scientific | 1978 |
| Silverstars Care Ltd | Transport & logistics | 2017 |
| Silverstars Estates Ltd | Construction | 2026 |
| Silverstars Group Ltd | Real estate | 2024 |
| Simcoe Advisory Ltd | Professional & scientific | 2025 |
| Simon Gillett Building Contractor Limited | Construction | 2003 |
| Simonyx Limited | Manufacturing | 2012 |
| Simply Advice Ltd | Professional & scientific | 2017 |
| Sixty 8 Solutions Ltd | Administrative & support | 2024 |
| Size Five Games Limited | Information & communication | 2008 |
| SJL Consulting Ltd | Professional & scientific | 2023 |
| SJN Decorating Services Ltd | Construction | 2020 |
| Skinny Dipper Clothing Ltd | Wholesale & retail | 2020 |
| Skunk Goods Trading Ltd | Wholesale & retail | 2016 |
| SLB (SW) Limited | Wholesale & retail | 2025 |
| Smart Treasure Limited | Real estate | 2023 |
| Smartees Day Care Nursery Limited | Health & social care | 2011 |
| Smarter Home Systems Limited | Wholesale & retail | 2017 |
| Smithsonian Grips Rigging Limited | Information & communication | 2024 |
| SMJ Fire & Security Ltd | Administrative & support | 2025 |
| SO Awkward Academy Series 2 Limited | Information & communication | 2023 |
| SO Awkward Movie Limited | Information & communication | 2022 |
| Soccer Star World Limited | Construction | 2001 |
| Sock Monkey Enterprises Limited | Information & communication | 2007 |
| Sollicker Limited | Administrative & support | 2001 |
| Somerset Hand Clinic Ltd | Health & social care | 2020 |
| Somerset Joinery & Design Ltd | Manufacturing | 2024 |
| Somerset Tyres & Servicing Ltd | Wholesale & retail | 2020 |
| Somerton LVA LLP | | 2022 |
| Somervilles Limited | Construction | 2004 |
| Sonoheart Diagnostics Limited | Health & social care | 2025 |
| Source Material Studio Limited | Professional & scientific | 2024 |
| South & West Wilts Farmers Collection Ltd | Agriculture & fishing | 2014 |
| South Facing Communications Ltd | Professional & scientific | 2021 |
| South Petherton Estates Ltd | Construction | 2026 |
| South Somerset Agricultural Preservation Club Limited | Arts & recreation | 1995 |
| South West Art Courses Ltd | Arts & recreation | 2022 |
| South West Electric Vehicles Ltd | Wholesale & retail | 2020 |
| Southern First AID Training Limited | Health & social care | 2007 |
| SP Massage Therapy Ltd | Other services | 2024 |
| Spalding LVA LLP | | 2017 |
| Sparcs (South West) Limited | Manufacturing | 2017 |
| Spark R&D UK Ltd | Wholesale & retail | 2026 |
| Sparkford LVA LLP | | 2015 |
| Sparkford Two LVA LLP | | 2019 |
| Sparks Media Publishing Ltd. | Information & communication | 2000 |
| Spatial Thinking Limited | Wholesale & retail | 2017 |
| SPC 2004 Holdings Limited | Financial services | 2013 |
| Spch Limited | Financial services | 2022 |
| Specialised Technologies Europe Ltd | Administrative & support | 2011 |
| Sports Select Ltd | Arts & recreation | 2009 |
| Sprocc Management Ltd | Real estate | 2025 |
| Square Hole Design Consultancy Limited | Professional & scientific | 2012 |
| SQUARE2CIRCLE Limited | Financial services | 2015 |
| SSC Group Holdings Ltd | Administrative & support | 2026 |
| SSS Limited Partnership | | 2001 |
| ST Swithin's Close Maintenance Limited | Households | 1967 |
| Stalbridge LVA LLP | | 2017 |
| Star House Financial Services Limited | Financial services | 2005 |
| Statement Property Group Ltd | Real estate | 2014 |
| Station RD Traders Limited | Real estate | 1998 |
| Stefan Shaw Studio Limited | Professional & scientific | 2018 |
| Stella Weatherall Limited | Professional & scientific | 2020 |
| Stephen Akins Consultancy Limited | Information & communication | 1990 |
| Steven John Holdings Limited | Professional & scientific | 2024 |
| Stitch Away Ltd | Wholesale & retail | 2025 |
| Stockwood Lettings Limited | Real estate | 2012 |
| Stoke ST Michael LVA LLP | | 2014 |
| Stone Facilities Management Ltd | Information & communication | 2024 |
| Storage Barn Ltd | Other services | 2017 |
| Store Your Stuff Limited | Transport & logistics | 2024 |
| Stour Carp Farm Limited | Agriculture & fishing | 2023 |
| Stour Hill House Estates Limited | Households | 2001 |
| Stour Management (Dorset) Limited | Other services | 2001 |
| Stream Design Limited | Professional & scientific | 2023 |
| Stud-Starter Ltd | Manufacturing | 2025 |
| Studio Colab Ltd | Professional & scientific | 2020 |
| Studio Dera Limited | Professional & scientific | 2020 |
| Studio Farbrother Ltd | Professional & scientific | 2025 |