| Stretch FL Ltd | Real estate | 2005 |
| Strictly Cars Limited | Transport & logistics | 2025 |
| Strike Force International Ltd | Transport & logistics | 2000 |
| String Virtuoso Limited | Information & communication | 2020 |
| Stronger Together Wellbeing CIC | Arts & recreation | 2024 |
| Strongstock Ltd | Wholesale & retail | 2025 |
| Struktee Ltd | Professional & scientific | 2020 |
| Stuart Ferris Limited | Manufacturing | 2008 |
| Stuart Rolt Specialist Cars Limited | Wholesale & retail | 2010 |
| Stuart Viggers Master Thatchers Limited | Construction | 2015 |
| Stud Farm Services Ltd | Households | 2024 |
| Studio 321 Ltd | Administrative & support | 2025 |
| Studio Anima Limited | Professional & scientific | 2024 |
| Studio Capelli Limited | Other services | 2016 |
| Studio Hoiho Limited | Information & communication | 2025 |
| Studio KOI Ltd | Arts & recreation | 2025 |
| Studio Wylder Limited | Manufacturing | 2021 |
| SU Banbury Ltd | Hospitality | 2026 |
| Sudfole Limited | Hospitality | 2008 |
| SUE Allan Freelance Ltd | Administrative & support | 2016 |
| Suebase Limited | Health & social care | 2025 |
| Suesam Services Banbury Limited | Transport & logistics | 2013 |
| Sugarboo Limited | Manufacturing | 2023 |
| Sugarswell Ltd | Financial services | 2026 |
| Sugarswell Studios Limited | Information & communication | 2016 |
| Sulgrave Manor Trading Company Limited | Real estate | 1999 |
| Summerville Limited | Real estate | 2000 |
| Summerville Properties Limited | Real estate | 2024 |
| Sun by ANN Limited | Other services | 2025 |
| Sunbeam Alpine Owners Club Limited | Other services | 2012 |
| Sunkissed Salon Limited | Other services | 2016 |
| Sunny Training Limited | Education | 2020 |
| Sunpor Taylor Limited | Wholesale & retail | 2025 |
| Sunset Displays Limited | Arts & recreation | 2021 |
| Sunshine Flower Limited | Hospitality | 2021 |
| Sunshine the Horse Limited | Arts & recreation | 2024 |
| Supacrops Arable Limited | Agriculture & fishing | 2020 |
| Super Finn Limited | Wholesale & retail | 2026 |
| Super Scanlon Ltd | Transport & logistics | 2025 |
| Supported by Research Community Interest Company | Professional & scientific | 2025 |
| Supra Steel Ltd | Construction | 2021 |
| Sure FIX Roofing Ltd | Construction | 2023 |
| Surgical Training Academy Ltd | Education | 2022 |
| Surplus Test Equipment Limited | Administrative & support | 2001 |
| Susan Dunstall Limited | Administrative & support | 2015 |
| Sushi ME Ltd | Hospitality | 2026 |
| Sutherland Car Care Ltd | Wholesale & retail | 2021 |
| Sutherland Home Care (Banbury) Limited | Administrative & support | 2022 |
| Sutton Westerman Limited | Professional & scientific | 2025 |
| Svml London Ltd | Professional & scientific | 2017 |
| SW Powder Coating Ltd | Manufacturing | 2016 |
| SW Technology Consulting Limited | Professional & scientific | 2021 |
| Swakara Ltd | Arts & recreation | 2015 |
| Swalcliffe Park Equestrian Ltd | Agriculture & fishing | 2011 |
| Swalcliffe Park Livery Ltd | Agriculture & fishing | 2007 |
| Swan Precision Castings and Engineering Ltd | Manufacturing | 1953 |
| Swan PUB Banbury Limited | Hospitality | 2013 |
| Swan Shephard Limited | Manufacturing | 1999 |
| Swann PUB Banbury Limited | Hospitality | 2013 |
| Swanton-Boyd Holdings Limited | Real estate | 2019 |
| Sweet Celebrations Limited | Wholesale & retail | 2007 |
| Sweet Comms Limited | Professional & scientific | 2014 |
| Swere Valley Ltd | Construction | 2020 |
| Swerford Advisors Limited | Real estate | 2015 |
| Swerford Limited | Professional & scientific | 2006 |
| Swift Ecology Ltd | Administrative & support | 2007 |
| Swift Go Ltd | Transport & logistics | 2020 |
| Swift Lift Rescue and Recovery Limited | Transport & logistics | 2025 |
| Swift Powered Access Ltd | Professional & scientific | 2024 |
| Swiftmove ASR Ltd | Transport & logistics | 2026 |
| Swiftsure Properties Limited | Administrative & support | 2013 |
| Swimming Pool Engineering Limited | Construction | 2015 |
| Swisslogo Manufacturing Ltd | Manufacturing | 2024 |
| Swisslogo UK Ltd | Manufacturing | 2024 |
| Switchpower Limited | Information & communication | 2005 |
| Sword Training Solutions Ltd | Professional & scientific | 2020 |
| SWT London Ltd | Financial services | 2025 |
| Sylla Development Ltd | Real estate | 2025 |
| Sylvester Oxford Limited | Wholesale & retail | 2002 |
| Sylvonne Healthcare Services Limited | Health & social care | 2018 |
| Symnel Consulting Ltd | Information & communication | 2014 |
| Symphony Change Ltd | Information & communication | 2024 |
| Synergy Clinical Ltd | Professional & scientific | 2017 |
| Synex Drivers Ltd | Transport & logistics | 2012 |
| Syston Ventures Limited | Hospitality | 2024 |
| SZK International Ltd | Construction | 2016 |
| T & B Building Ltd | Construction | 2020 |
| T & C Scaffolding Ltd | Construction | 2025 |
| T & K (Bicester) Ltd | Other services | 2026 |
| T & M Cooper Limited | Agriculture & fishing | 2007 |
| T a Birks Limited | Financial services | 2019 |
| T C Graham Ltd | Extraterritorial | 2023 |
| T C Rowan Co Ltd | Manufacturing | 2023 |
| T Jeffs Accounting Services Limited | Professional & scientific | 2021 |
| T L Hall Limited | Financial services | 2018 |
| T M Humphrey Limited | Financial services | 2019 |
| T P Building Services (Banbury) Ltd | Construction | 2024 |
| T&C Property Group Ltd. | Construction | 2019 |
| T&F Developments Ltd | Real estate | 2025 |
| T&S Music Limited | Administrative & support | 2016 |