| Speaking Truth to Power(S) Limited | Information & communication | 2023 |
| Speccy Shop Ltd | Wholesale & retail | 2024 |
| Special Project Group Ltd | Administrative & support | 2025 |
| Special Treasures Childcare Limited | Health & social care | 2009 |
| Special Treasures Foundation Ltd | Other services | 2011 |
| Specialised Microelectronics Limited | Professional & scientific | 2025 |
| Specialist Car House Ltd | Wholesale & retail | 2022 |
| Specialists Accident Repair Group Ltd | Wholesale & retail | 2024 |
| Spectra Rope Access NDT Limited | Professional & scientific | 2011 |
| Spectra Properties Limited | Real estate | 1996 |
| Spectral X Limited | Professional & scientific | 2014 |
| Spectre BIO Limited | Professional & scientific | 2025 |
| Spectrum (Limited Partner) Ltd | Administrative & support | 2002 |
| Speedwell Communications Limited | Professional & scientific | 2023 |
| Speedy Screeding Ltd | Administrative & support | 2018 |
| Spego Management Limited | Extraterritorial | 2010 |
| Spencer & West Estates Ltd | Real estate | 2025 |
| Spencer & West Limited | Real estate | 2024 |
| Sphinx Services Limited | Professional & scientific | 2001 |
| Spice Island Leisure Limited | Hospitality | 1999 |
| Spice Maison Ltd | Hospitality | 2025 |
| Spicebox Takeaway Ltd | Hospitality | 2017 |
| Spiced Roots Ltd | Hospitality | 2016 |
| Spiers Specialist Carpentry Limited | Construction | 2001 |
| Spinks Emedia Limited | Information & communication | 2007 |
| Spintex Engineering Limited | Professional & scientific | 2018 |
| Spira Consulting Ltd | Professional & scientific | 2022 |
| Spiralling Crow Limited | Education | 2019 |
| Spires and Fields Builders Ltd | Construction | 2020 |
| Spires Capital Investments Limited | Real estate | 2017 |
| Spires Ecology Ltd | Professional & scientific | 2014 |
| Spires House Management Limited | Households | 2015 |
| Spires INS Brokers Ltd | Financial services | 2023 |
| Spires Legal Limited | Professional & scientific | 2018 |
| Spires Taxis Ltd | Transport & logistics | 2025 |
| Spirits and Whisky Ltd. | Wholesale & retail | 1992 |
| SPJ Professional Services Limited | Professional & scientific | 2014 |
| SPK Endo Ltd | Health & social care | 2014 |
| Splash Trades Ltd | Wholesale & retail | 2015 |
| Split Records Ltd | Arts & recreation | 2003 |
| Sportcruiser 290 Limited | Arts & recreation | 2016 |
| Sports & Musculoskeletal Radiology Ltd | Health & social care | 2023 |
| Spotlight Promo Ltd | Hospitality | 2023 |
| Spradling UK Limited | Wholesale & retail | 2005 |
| Springfield NOW Limited | Construction | 2019 |
| Sprint 10 Limited | Information & communication | 2022 |
| Sprout Projects Limited | Hospitality | 2015 |
| Spruce IT UP Ltd. | Administrative & support | 2010 |
| SPT Engineering Consulting Ltd | Professional & scientific | 2024 |
| SPX Oxford Ltd. | Professional & scientific | 2012 |
| Spybiotech Limited | Professional & scientific | 2017 |
| Squaducation Limited | Education | 2014 |
| Squirrel Gifts Limited | Real estate | 2016 |
| Squirrel Innovations Limited | Wholesale & retail | 2017 |
| Squitchey Services Limited | Information & communication | 2010 |
| SQW Group Limited | Administrative & support | 2003 |
| SQW Group Newco 2018 Ltd | Administrative & support | 2018 |
| SQW Limited | Professional & scientific | 1983 |
| SR Consulting Limited | Professional & scientific | 2022 |
| Sravni Global Ltd | Real estate | 2026 |
| Srboosted Ltd | Wholesale & retail | 2026 |
| SRJ Associates (Oxford) Limited | Construction | 2017 |
| SRJ Consulting (Oxford) Ltd | Construction | 2025 |
| Sroland Trade Limited | Wholesale & retail | 2022 |
| SRS Home Management Ltd | Households | 2025 |
| SS3 Ltd | Administrative & support | 2020 |
| Ssgd Prime Limited | Wholesale & retail | 2022 |
| Ssheth Ventures Limited | Wholesale & retail | 2026 |
| Sssox Consulting Ltd | Health & social care | 2024 |
| ST Aldates Property Management Ltd | Real estate | 2015 |
| ST Anne's College Developments Limited | Construction | 2003 |
| ST Anne's College Services Company Limited | Hospitality | 2001 |
| ST Catherine's College Development Limited | Construction | 2001 |
| ST Catherine's College Management Limited | Hospitality | 2001 |
| ST Clement's Community Property Trust | Real estate | 2021 |
| ST Clements Property Management Company Limited | Construction | 2008 |
| ST Edmund Hall Design & Build Limited | Construction | 2015 |
| ST Edmund Hall Trading | Hospitality | 2012 |
| ST Edward's School International Limited | Education | 2017 |
| ST Hilda's College (Trading) Ltd | Other services | 2009 |
| ST Hilda's College Developments Ltd | Construction | 2017 |
| ST Hugh's Conferences Limited | Hospitality | 2006 |
| ST Hugh's Estates Limited | Construction | 2011 |
| ST John Street Limited | Extraterritorial | 2007 |
| ST John's College Services Limited | Other services | 2019 |
| ST Joseph the Worker Ltd | Health & social care | 2020 |
| ST Katherine Financial Services Ltd | Information & communication | 2018 |
| ST Luke's Diagnostics Clinic Oxford Ltd | Education | 2026 |
| ST Luke's Radiology Oxford Ltd | Education | 2017 |
| ST Mary's Church Trading Limited | Wholesale & retail | 2024 |
| ST Michael's and Ship Street Properties Ltd | Real estate | 2024 |
| ST Nicholas Mews Management Company Limited | Households | 2004 |
| ST Peter's College Design and Build Limited | Construction | 2016 |
| ST Peter’S College Conference and Events Limited | Hospitality | 2023 |
| ST Properties Holdings Ltd | Real estate | 2022 |
| ST Stephen's House Trading Limited | Hospitality | 2018 |
| ST. Antony's College Estates Limited | Construction | 2010 |
| ST. Antony's College Trading Limited | Administrative & support | 2010 |
| ST. Christopher's Court (Cowley) Management Company Limited | Households | 1995 |
| ST. Clements (Oxford) Limited | Households | 1982 |