| ST. George's Laundry Ltd | Other services | 2013 |
| ST. Michael Limited | Wholesale & retail | 2004 |
| ST. Nicholas Court (Crawley) Management Company Limited | Households | 1988 |
| ST. Noha Services Limited | Extraterritorial | 2000 |
| St.Kyrillos Ltd | Wholesale & retail | 2016 |
| Stack for Business Ltd | Professional & scientific | 2017 |
| Stairbridge Court Management Limited | Real estate | 2015 |
| Stalwart Trading Ltd | Wholesale & retail | 2014 |
| Stamford Lodge Limited | Real estate | 2004 |
| Stanbridge House Limited | Health & social care | 2012 |
| Standing Investment Ltd | Real estate | 2017 |
| Standing Management Ltd | Real estate | 2016 |
| Standing Trading Ltd | Construction | 2024 |
| Stanford Burn Ltd | Professional & scientific | 2018 |
| Stanger Road Management Limited | Real estate | 2002 |
| Stanhope Solutions Limited | Information & communication | 2007 |
| Stanley 2014 Limited | Energy | 2014 |
| Stanley RE Commercial Limited | Real estate | 2021 |
| Stanley RE Investments Ltd | Real estate | 2017 |
| Stanton Beach Ltd | Professional & scientific | 2024 |
| Stanza RTM Company Limited | Extraterritorial | 2025 |
| Star BM Ltd | Real estate | 2019 |
| Star Brunswick Limited | Real estate | 2018 |
| Star Camelford Limited | Real estate | 2018 |
| Star Community Housing CIC | Real estate | 2019 |
| Star Cromwell Limited | Real estate | 2021 |
| Star Education Services Limited | Education | 2022 |
| Star Events Sussex Ltd | Hospitality | 2019 |
| Star Garages (Brighton) Limited | Wholesale & retail | 1971 |
| Star IC Limited | Financial services | 2020 |
| Star PAY Benefits Limited | Administrative & support | 2025 |
| Star Performance (Brighton) Limited | Arts & recreation | 2012 |
| Star Property Capital Investments Limited | Real estate | 2021 |
| Star Property Capital Limited | Real estate | 2022 |
| Star Property Investment & Management Limited | Real estate | 2015 |
| Star Racing Limited | Arts & recreation | 2008 |
| Star Sports (on Course) Limited | Arts & recreation | 2010 |
| Star Sports Limited | Extraterritorial | 2009 |
| Star Sports Recruitment Limited | Administrative & support | 2018 |
| Star Sports Retail Limited | Arts & recreation | 1984 |
| Starah Ltd | Information & communication | 2007 |
| Starfish Kids Club Limited | Education | 2000 |
| Starling Co-Op Limited | Hospitality | 2017 |
| Starnes & Co Ltd | Real estate | 2013 |
| Starns Labs Limited | Information & communication | 2018 |
| Start to Scale Talent Services Ltd | Administrative & support | 2024 |
| Start Trade Limited | Hospitality | 2010 |
| Station Mews Ltd | Administrative & support | 2014 |
| Station Taxis Lewes Ltd | Transport & logistics | 2025 |
| Staveley Court Eastbourne Limited | Households | 2004 |
| Stay and Play Ltd | Education | 2015 |
| Stay Puft Properties Limited | Real estate | 2025 |
| STE Property Investment Ltd | Real estate | 2024 |
| Steady Flow Consulting Ltd | Professional & scientific | 2021 |
| Steam Rocket Ltd | Wholesale & retail | 2020 |
| Stearns Communications Limited | Professional & scientific | 2024 |
| Stefan Surf Shop Brighton Limited | Wholesale & retail | 2025 |
| Stellar Domestic Services Limited | Administrative & support | 2012 |
| Stellar Pharma Ltd | Professional & scientific | 2011 |
| Stellarmann Group Ltd | Financial services | 2019 |
| Stellarmann Professional Services Ltd | Professional & scientific | 2019 |
| Stencil Audio Ltd | Manufacturing | 2026 |
| Stephen K Spears Limited | Wholesale & retail | 2008 |
| Stepney Trading Limited | Wholesale & retail | 2019 |
| Sterk Properties Ltd | Real estate | 2023 |
| Sterlingcleanenergy Limited | Professional & scientific | 2026 |
| Sterny Limited | Hospitality | 2014 |
| Steve Darby Associates Limited | Professional & scientific | 2020 |
| Steve Gray GAS Services Ltd | Construction | 2023 |
| Steve Rooke Limited | Construction | 1998 |
| Steve Tempia Editor Limited | Information & communication | 2003 |
| Steven Cymbler & Associates Ltd | Professional & scientific | 2025 |
| Steven Edwards Ltd | Administrative & support | 2016 |
| Steven Maiden Engineering Ltd | Professional & scientific | 2022 |
| Stevenson & Sons Construction Ltd | Construction | 2024 |
| Stevenson Electrical Limited | | 1980 |
| Stevie Britton Limited | Construction | 2019 |
| Stewart House Hove Limited | Real estate | 2006 |
| Stewart Mouland Motor Caravans Limited | Wholesale & retail | 1990 |
| Stickyback Pictures Limited | Information & communication | 2011 |
| Stitch Group Holdings Limited | Extraterritorial | 2013 |
| Stitch Group Limited | Wholesale & retail | 2008 |
| Stock Development Limited | Real estate | 2004 |
| Stockcape Investments Ltd | Real estate | 2025 |
| Stockcape Ltd | Real estate | 2019 |
| Stockleigh Road Ltd | Construction | 2020 |
| Stockshed Limited | Professional & scientific | 2013 |
| Stockshed Metering Limited | Wholesale & retail | 2024 |
| Stompstamps Ltd | Wholesale & retail | 2014 |
| Stone & Co People Management Ltd | Administrative & support | 2025 |
| Stone & Co Property Investment Ltd | Real estate | 2025 |
| Stone Carpets (Sussex) Ltd | Wholesale & retail | 2016 |
| Stone Court (Hove) Limited | Real estate | 2008 |
| Stone Enterprises Limited | Wholesale & retail | 1962 |
| Stone House Property Holdings Limited | Real estate | 2022 |
| Stone Street Limited | Households | 2010 |
| Stonechris Properties Limited | Real estate | 2014 |
| Stoneglade Property Management Limited | Households | 2009 |
| Stoneham Bakehouse CIC | Manufacturing | 2015 |
| Stoneman Properties Limited | Other services | 2019 |