| S.J.Reed and SON Electrical Engineers Ltd | Construction | 2012 |
| Safe Harbour Homecare Limited | Health & social care | 2012 |
| Sailing Hols Limited | Arts & recreation | 2006 |
| Sails Management Company Limited | Households | 2008 |
| Salesplan CRM Ltd | Information & communication | 2018 |
| Sallie Adams Limited | Other services | 2018 |
| Salterns Business Services Limited | Professional & scientific | 2020 |
| Saltwell Candles Limited | Manufacturing | 2025 |
| Salurate Limited | Professional & scientific | 2011 |
| Sandbanks Estates Limited | Other services | 2002 |
| Sandford REX Ltd | Transport & logistics | 2016 |
| Sarah O'Brien Limited | Other services | 2023 |
| Savile Capital Ltd | Financial services | 2009 |
| Savros Investments Limited | Real estate | 2017 |
| SBG Holdings Limited | Financial services | 2015 |
| Scarab Soap Co Limited | Arts & recreation | 1999 |
| Scarfe Lendvai Limited | Administrative & support | 2021 |
| Scenarworld Ltd | Health & social care | 2016 |
| Scout Recruitment Limited | Administrative & support | 1998 |
| Scrabulizer Limited | Information & communication | 2011 |
| SD Integrated Security Systems Limited | Administrative & support | 2011 |
| SD Structures Ltd | Construction | 2022 |
| Sdrm Catering Ltd | Extraterritorial | 2011 |
| SE16 LLP | | 2014 |
| Sean Madgwick Construction Services Ltd | Construction | 2014 |
| Second BED Films Limited | Information & communication | 2015 |
| Self LED Psychology Ltd | Health & social care | 2022 |
| SEO Designed Ltd | Extraterritorial | 2016 |
| Sesys Limited | Manufacturing | 2003 |
| Seven Summits Performance Limited | Administrative & support | 2006 |
| SEW Creative Ltd. | Wholesale & retail | 2012 |
| Seyoki Limited | Agriculture & fishing | 2011 |
| Sharon Francine Slights Limited | Extraterritorial | 2022 |
| Sheldon-Hill Residential Limited | Real estate | 2020 |
| Shelfco NO. 99 Limited | | 1977 |
| Shepherd Contracting West Sussex Ltd | Manufacturing | 2021 |
| Shine Radio Ltd | Information & communication | 2023 |
| Shinsen II Ltd | Hospitality | 2024 |
| Shrunken Head Incorporated Ltd | Other services | 2016 |
| Shrunken Head Skates Ltd | Wholesale & retail | 2021 |
| Sightsize Limited | Education | 2020 |
| Sightsplash Ltd | Real estate | 2015 |
| Signature Kitchen Designs Limited | Manufacturing | 2012 |
| Silvertail Limited | Professional & scientific | 2000 |
| Simon Burles Broadcast Sound Limited | Information & communication | 2004 |
| Simon Constable Limited | Transport & logistics | 2016 |
| Simon Horn Furniture Limited | Manufacturing | 2012 |
| Simon Sound Ltd | Information & communication | 2020 |
| Simon-Paul Land Limited | Construction | 2010 |
| Simplyneat Fire Solutions Ltd | Public administration | 2021 |
| Sinouk Sourcing Ltd | Wholesale & retail | 2022 |
| Sithean Solutions Limited | Professional & scientific | 2009 |
| SJC Software Consulting Ltd | Information & communication | 2012 |
| Skillbase People Development Limited | Extraterritorial | 2022 |
| Skills Depot Ltd | Construction | 2019 |
| Skinner Inns Ltd | Hospitality | 2024 |
| Sky I Images Limited | Extraterritorial | 2022 |
| SL8 Entertainment Limited | Arts & recreation | 2025 |
| Sloth OR Beaver Ltd | Wholesale & retail | 2025 |
| SLT Paving Limited | Administrative & support | 2019 |
| Smarter Business Consultancy Ltd | Professional & scientific | 2015 |
| Smarter Property Investment Ltd | Real estate | 2016 |
| SMI INT Group Limited | Administrative & support | 2011 |
| Smoked Co Ltd | Wholesale & retail | 2025 |
| SND Properties Group Ltd | Real estate | 2026 |
| Snowball Productions Limited | Information & communication | 2022 |
| Soda Guitars Ltd | Manufacturing | 2026 |
| Solent Developments Ltd | Real estate | 2013 |
| Sonnet Technologies Limited | Information & communication | 2024 |
| Sosha Ltd | Wholesale & retail | 2011 |
| Source Code Messaging Ltd | Information & communication | 2026 |
| Source Enterprises Limited | Information & communication | 2000 |
| South Coast Firewood Ltd | Agriculture & fishing | 2013 |
| South Downs Forage & Feeds Limited | Agriculture & fishing | 2018 |
| South Downs Gardens Ltd | Administrative & support | 2026 |
| South Downs Natural Burial Site Ltd | Other services | 2007 |
| South Point Carpentry Ltd | Construction | 2023 |
| Southdowns Hotels & Restaurants Limited | Hospitality | 1983 |
| Southern IT Experts Limited | Information & communication | 2008 |
| Southern Jewellers Limited | Extraterritorial | 2017 |
| Southgold Capital Limited | Administrative & support | 2008 |
| Southover Ltd | Financial services | 2024 |
| Sovereign Protection Ltd | Administrative & support | 2024 |
| Speirs Plumbing & Heating Limited | Construction | 2018 |
| Spire Consultancy Ltd | Real estate | 2012 |
| Spitfire Grills Limited | Manufacturing | 2022 |
| SPK Consulting Ltd | Public administration | 2026 |
| Square Executor and Trustee Company (the) | Extraterritorial | 1969 |
| Squirrel and Magpie Limited | Wholesale & retail | 2021 |
| ST. James Marketing Limited | Professional & scientific | 2003 |
| ST. Martins Lodge Residents Association (Southsea) Limited | Households | 1986 |
| ST. Michael Advisory Limited | Professional & scientific | 2025 |
| Stanhope Cooper Insurance Brokers Limited | Financial services | 2005 |
| Stanley J Property Ltd | Real estate | 2024 |
| Star Light Bridlington Private Trust Limited | Extraterritorial | 2023 |
| Star Light London Private Trust Limited | Extraterritorial | 2025 |
| Star Light Spain Private Trust Limited | Extraterritorial | 2023 |
| Star Wealth Limited | Financial services | 2016 |
| Starline Install Ltd | Construction | 2020 |
| Steadyshare Trading Limited | Real estate | 1993 |