| Simon Interiors Limited | Wholesale & retail | 1997 |
| Simon Thornley Limited | Other services | 2005 |
| Simong Limited | Professional & scientific | 1999 |
| Singh Inc Ltd | Transport & logistics | 2021 |
| Sinova International Trading Co., Ltd. | Wholesale & retail | 2025 |
| Siyu Cross Border Business Service Co., Ltd | Wholesale & retail | 2022 |
| SJ Steel Fitters Ltd | Construction | 2019 |
| Sjrp Group Holdings Limited | Financial services | 2025 |
| SJT Building Work Ltd | Construction | 2015 |
| SK Heathrow Lodge Ltd | Hospitality | 2022 |
| SK8HIRE Ltd | Arts & recreation | 2017 |
| Skilled Manufacturing Limited | Manufacturing | 1990 |
| Skyline Foam & Fibre (UK) Ltd | Manufacturing | 2019 |
| Slice Pizza & Grill Limited | Hospitality | 2022 |
| SLR Software Accountancy Services Limited | Professional & scientific | 1999 |
| Slug and Lettuce Trading Limited | Hospitality | 2025 |
| SM Locum Services Limited | Health & social care | 2003 |
| SM Properties (Estates) Limited | Real estate | 1997 |
| Smallbone & SON Service Station Limited | Wholesale & retail | 1949 |
| Smart Bodyshop Solutions (Exeter) Ltd | Wholesale & retail | 2019 |
| Smart Holdings Solutions Ltd | Real estate | 2019 |
| Smart Investment Properties Limited | Real estate | 2004 |
| Smartfit Blinds Limited | Manufacturing | 2006 |
| Smarto Trading UK Ltd | Information & communication | 2024 |
| SMB Refrigeration Limited | Administrative & support | 2005 |
| Smestow Pattern & Tool Company Limited | Other services | 1991 |
| Smethwick Coatings Limited | Professional & scientific | 2003 |
| Smethwick Fabrications Limited | Manufacturing | 1963 |
| Smethwick Industrial Services Limited | Construction | 1972 |
| Smethwick Security Services Limited | Professional & scientific | 1978 |
| Smethwick Youth & Community Centre Limited | Health & social care | 2001 |
| Smile Grape Ltd | Information & communication | 2023 |
| Smith Rook Associates Limited | Professional & scientific | 2017 |
| Smithsons Limited | Administrative & support | 2006 |
| Smkm (Holdings) Limited | Financial services | 2001 |
| Snobs Management Limited | Financial services | 2002 |
| Snow Leopard E-Commerce Group Co., Limited | Wholesale & retail | 2023 |
| SO Solve Limited | Information & communication | 2002 |
| Sobach Lighting Ltd | Wholesale & retail | 2023 |
| Solar & Wind Integration Limited | Professional & scientific | 2025 |
| Solar Energy (GB) Limited | Wholesale & retail | 2006 |
| Solar RGB Ltd | Construction | 2007 |
| Solid Engineering Limited | Manufacturing | 1951 |
| Solid Investment Company Limited | Real estate | 2002 |
| Solid Stampings Limited | Manufacturing | 1971 |
| Solid Swivel Company Limited(The) | Manufacturing | 1950 |
| Solihull Community Housing Limited | Real estate | 2002 |
| Solihull Cricket & Tennis Ground Limited | Arts & recreation | 1953 |
| Solihull Projects Ltd | Professional & scientific | 2007 |
| Solihull Properties Limited | Real estate | 2003 |
| Solihull Rifle & Pistol Club | Arts & recreation | 2012 |
| Solihull School | Education | 2007 |
| Solmax Geosynthetics (UK) Ltd | Wholesale & retail | 1992 |
| Solomon Europe Ltd | Administrative & support | 2006 |
| Solutions Acrylic and Display Limited | Manufacturing | 1993 |
| Sonique International Limited | Wholesale & retail | 2023 |
| Sorted Direct Group Limited | Financial services | 2022 |
| Sorted Direct Mail Limited | Professional & scientific | 2009 |
| Soundtek Limited | Professional & scientific | 2006 |
| South East Galvanizers Limited | Manufacturing | 1996 |
| South Ribble Timber Co. Limited | Professional & scientific | 1963 |
| South Staffordshire Water PLC | Water & waste | 1991 |
| South West Galvanizers Limited | Manufacturing | 1985 |
| Southrock Limited | Real estate | 1993 |
| Spain Peloge Especiales Limited | Manufacturing | 2023 |
| Sparmanor Limited | | 1974 |
| Spearhead Property Developments Limited | Real estate | 1995 |
| Specialist Jewellery Services Limited | Manufacturing | 2006 |
| Speech Therapy Central Ltd | Health & social care | 2021 |
| Speedform Tools (Midlands) Limited | Manufacturing | 1972 |
| Speedway Garage (1983) Limited | Wholesale & retail | 1983 |
| Spice Inn Balti Ltd | Hospitality | 2021 |
| Spices (Catshill) Ltd | Hospitality | 2006 |
| Spilman Associates Limited | Professional & scientific | 2000 |
| Spire Manufacturing Limited | Financial services | 2012 |
| Spirevalley Ltd | Real estate | 1999 |
| Spirotech Environmental Energy Technology Co., Ltd | Extraterritorial | 2023 |
| SPM Associates (West Midlands) Limited | Professional & scientific | 2001 |
| Sponmech Safety Systems Limited | Manufacturing | 1991 |
| Sportio Limited | Wholesale & retail | 1995 |
| Sports Education Development Ltd | Education | 2000 |
| Springfield Architectural Services Limited | Professional & scientific | 2004 |
| Springsphere Limited | Extraterritorial | 2012 |
| Sprinkler Irrigation Systems Limited | Construction | 2002 |
| Spunalloys Limited | Manufacturing | 1988 |
| Squeezyjazzy Ltd | Administrative & support | 2020 |
| SR Commercial Limited | Construction | 2003 |
| SR2D2 Properties Ltd | Real estate | 2021 |
| SR7-EG Ltd | Wholesale & retail | 2025 |
| SS7 Services Ltd | Administrative & support | 2026 |
| ST Cecilia's Limited | Real estate | 1995 |
| ST Jude Hospitals & Clinics Limited | Health & social care | 2007 |
| ST Katharine Estate NO.1 Limited Partnership | | 2002 |
| ST Katharine Estate NO.2 Limited Partnership | | 2002 |
| ST. Paul's Printing & Label Co. Limited | Manufacturing | 1949 |
| ST. Pauls Mint Limited | Manufacturing | 2003 |
| ST. Philip's Chambers Limited | Administrative & support | 1998 |
| Staff Select Ltd | Education | 1993 |
| Staging Services Limited | Arts & recreation | 2000 |
| Stainless Steels (Processing) Limited | Extraterritorial | 1968 |