| Savvy Holdings Ltd | Financial services | 2023 |
| Savvy Maintenance & Renovations Ltd | Construction | 2010 |
| Savvy Renovations Limited | Construction | 2023 |
| Savvy Special Projects Limited | Construction | 2023 |
| Saxby Property Ltd | Hospitality | 2021 |
| Saxen Pictures Ltd | Information & communication | 2018 |
| Saxon Way (Headington) Management Company Limited | Households | 2005 |
| SAY Estates Ltd | Real estate | 2020 |
| Sayuri Accessories Ltd | Wholesale & retail | 2026 |
| SB Hygiene Limited | Health & social care | 2021 |
| SB MSK Services Ltd | Other services | 2023 |
| SBD Properties Limited | Real estate | 2022 |
| SBG Civils Ltd | Construction | 2019 |
| SC Property Consultancy Ltd | Construction | 2024 |
| SCA - Oxford Ltd | Arts & recreation | 2025 |
| Scaff Media Ltd | Construction | 2025 |
| Scala House Management Company Ltd | Households | 2020 |
| Scale UP Development Ltd | Education | 2025 |
| Scale UP Legal Consultancy Ltd | Professional & scientific | 2026 |
| Scalertech Solutions Ltd | Information & communication | 2025 |
| Scancell Holdings PLC | Professional & scientific | 2008 |
| Scancell Limited | Professional & scientific | 1996 |
| Scane and Sons Limited | Agriculture & fishing | 2019 |
| Scarabus Trading Limited | Arts & recreation | 2011 |
| Scarlett Orange Ltd | Wholesale & retail | 2021 |
| Scarletts Services Limited | Professional & scientific | 2019 |
| Scentral Collective Ltd | Professional & scientific | 2026 |
| Schedl Automotive System Service Ltd | Manufacturing | 2005 |
| Schlatter Consulting Limited | Professional & scientific | 2009 |
| Schleising Voice Services Limited | Information & communication | 2019 |
| Scholar's Place (Littlemore) Management Company Limited | Households | 2009 |
| Scholars Corner Management Company Limited | Households | 2022 |
| Scholars on Tour Limited | Administrative & support | 2024 |
| Scholastica Ltd | Education | 2022 |
| School Building Estates Limited | Extraterritorial | 2007 |
| School Building Limited | Extraterritorial | 2007 |
| School Building Properties Limited | Extraterritorial | 2007 |
| School Resources Exchange Ltd | Education | 2018 |
| Schytherbolle Limited | Professional & scientific | 2009 |
| Sci-Ink Limited | Information & communication | 2002 |
| Science Research Analysis Ltd | Other services | 2019 |
| Scientific and Technical Limited | Professional & scientific | 2024 |
| Scilogica Ltd | Professional & scientific | 2019 |
| Sciphy Limited | Professional & scientific | 2016 |
| Scolab Training and Consulting Ltd | Professional & scientific | 2024 |
| Scope Security Ltd | Administrative & support | 2011 |
| Scotica Capital Ltd | Financial services | 2025 |
| Scott Hughes Design Ltd | Professional & scientific | 2003 |
| Scott Tools Limited | Manufacturing | 2008 |
| Scott-Dearing Consulting Ltd | Arts & recreation | 2020 |
| Scottscott&Co LLP | | 2026 |
| Scoutcro Ltd | Information & communication | 2021 |
| SCP Plumbing Services Limited | Other services | 2013 |
| SCR Innovation Ltd | Professional & scientific | 2024 |
| Screenclay FX Limited | Arts & recreation | 2017 |
| Screensmart Ltd | Information & communication | 2020 |
| Scribble Games Ltd | Information & communication | 2014 |
| Scripta Therapeutics Limited | Professional & scientific | 2024 |
| Scroggs Dairies Limited | Construction | 1960 |
| Scrumblz Ltd | Information & communication | 2019 |
| SDC Healthcare Solutions Limited | Health & social care | 2014 |
| Sdfj Limited | Education | 2025 |
| Sdjw Limited | Administrative & support | 1993 |
| Sea Buckthorn Ltd | Wholesale & retail | 2024 |
| Seabrook Services Ltd | Health & social care | 2016 |
| Seabrook Wines Limited | Wholesale & retail | 2012 |
| Seaglass Cloud Technology Group Limited | Information & communication | 2018 |
| Seaglass Cloud Technology Limited | Information & communication | 2017 |
| Seahound Films Limited | Information & communication | 2011 |
| Seak Therapy Limited | Health & social care | 2023 |
| Seasearch AI Ltd. | Information & communication | 2025 |
| Sebaka Limited | Health & social care | 2024 |
| Sebale Consulting Limited | Professional & scientific | 2011 |
| Secac Ltd | Professional & scientific | 2026 |
| Second Epic Ltd | Professional & scientific | 2021 |
| Second Spring Oxford Limited | Professional & scientific | 2010 |
| Secret Shoppers UK Limited | Wholesale & retail | 2014 |
| Secstrike UK Ltd | Administrative & support | 2025 |
| Secure Records & Data Management Limited | Administrative & support | 2010 |
| Securezone(Uk) Ltd | Wholesale & retail | 2025 |
| Securmed UK | Other services | 2016 |
| SEE Change Ltd | Information & communication | 2003 |
| Seeing Social Ltd | Administrative & support | 2017 |
| Seenohearno Ltd | Professional & scientific | 2025 |
| Seequants Analytics Limited | Professional & scientific | 2015 |
| Seesaw | Health & social care | 1999 |
| Seev Technologies Ltd | Information & communication | 2023 |
| SEI Oxford Office Limited | Professional & scientific | 2002 |
| Seisma Magazine Ltd | Information & communication | 2019 |
| SEL 99 Limited | Manufacturing | 1929 |
| Selbert Ltd | Wholesale & retail | 2022 |
| Selcross Properties Limited | Households | 1976 |
| Seldory Consultancy Limited | Health & social care | 2019 |
| Select Academic Publishing Oxfordshire Limited | Information & communication | 2015 |
| Selesta Ltd | Construction | 1998 |
| Selexion Ltd | Wholesale & retail | 2023 |
| Self Assured Underwriting Agencies Limited | Financial services | 1999 |
| Self Storage Centre Limited | Transport & logistics | 2006 |
| Seller Excellence Ltd | Wholesale & retail | 2023 |
| Sellupnow Limited | Wholesale & retail | 2025 |