| Rural Property Consultancy Limited | Professional & scientific | 2019 |
| Ruskin Place (Oxford) Management Limited | Households | 1999 |
| Ryan Boswell Ltd | Construction | 2024 |
| Ryan Construction (Oxford) Limited | Construction | 2021 |
| S.E.A (U.K) Developments Ltd | Real estate | 2012 |
| Sacha Corp Limited | Wholesale & retail | 2016 |
| Saddlers Way (Ascot) Management Company Limited | Households | 2014 |
| Sadika-Vale Ltd | Financial services | 2010 |
| Salkamja Hair Limited | Other services | 2017 |
| Salon 77 Oxford Ltd | Other services | 2020 |
| Samhedges Limited | Health & social care | 2011 |
| Samuel Fitted Furniture Ltd | Manufacturing | 2025 |
| Sandbox Design and Build Ltd | Construction | 2026 |
| Sandcastle Mortgages (Oxford) Limited | Financial services | 2017 |
| Sandford Heights Residents Company Limited | Households | 1992 |
| Sandstone Law LLP | | 2020 |
| SAR UK Ltd | Manufacturing | 2007 |
| Sasdru Ltd. | Information & communication | 2017 |
| Savitar Shoes Ltd | Wholesale & retail | 2021 |
| Savona Foodservice Ltd | Wholesale & retail | 2003 |
| Saya Skin Services Limited | Health & social care | 2019 |
| Sbbaby Ltd | Health & social care | 2023 |
| Scarlet Cedano MUA Ltd | Wholesale & retail | 2019 |
| Scfsp Ltd. | Extraterritorial | 2017 |
| Scholars Mews Apartments Freehold Limited | Real estate | 2014 |
| Sciconsult Limited | Professional & scientific | 2017 |
| Scintilla Films Limited | Information & communication | 2011 |
| Scion Services Limited | Construction | 2021 |
| Screen Resource Limited | Information & communication | 1990 |
| SDH Builders Ltd | Construction | 2012 |
| Segun Obadje Teaching Ministries | Other services | 2024 |
| SEN Consultancy London Limited | Education | 2012 |
| SET the Space Limited | Real estate | 2025 |
| Seven Informatics Limited | Information & communication | 2013 |
| Shabeel Ltd | Wholesale & retail | 2025 |
| Shadowcell Limited | Extraterritorial | 1979 |
| Shaliz Limited | Real estate | 2020 |
| Shan DOC Ltd | Health & social care | 2024 |
| SHC GP LLP | | 2021 |
| Sheehan Haulage & Plant Hire Limited | Manufacturing | 1988 |
| Sheehans Limited | Real estate | 1986 |
| SHEIKH05 Limited | Administrative & support | 2025 |
| Shenley Apartments Ltd | Real estate | 2011 |
| Sherb UK Ltd. | Manufacturing | 2007 |
| Shore 9 Holdings Limited | Households | 2025 |
| Siamed Limited | Health & social care | 2018 |
| Silkscaped Limited | Wholesale & retail | 2025 |
| Silver Foodservice Limited | Wholesale & retail | 2015 |
| Silver Light Media Limited | Information & communication | 2000 |
| Silver Light Productions Limited | Information & communication | 1984 |
| Silver Saker Ltd | Wholesale & retail | 2026 |
| Silverdale Path Limited | Other services | 2026 |
| Sinclaire Eyewear Limited | Wholesale & retail | 2025 |
| Sirius B Ltd | Administrative & support | 2003 |
| Sisu Apparel Ltd | Wholesale & retail | 2025 |
| Sjokic Limited | Health & social care | 2018 |
| Sketch Labs Limited | Real estate | 2019 |
| SKP3 Ltd | Professional & scientific | 2020 |
| Sliced White Ltd. | Manufacturing | 2001 |
| Slicksound Limited | Extraterritorial | 1980 |
| Small Steps Day Nursery Ltd | Health & social care | 2019 |
| Smarts Properties Development Ltd | Other services | 2019 |
| SMG Ductwork Services Ltd | Administrative & support | 2007 |
| Smile With US Limited | Health & social care | 2018 |
| Snips Hair Salon Ltd | Other services | 2016 |
| Social Pottery Oxford Ltd | Wholesale & retail | 2025 |
| Socialmediauk Ltd | Wholesale & retail | 2010 |
| Solar Materials Technology Limited | Professional & scientific | 2014 |
| Solid Finance and Accountancy Limited | Financial services | 2021 |
| Solomon Sahonta Ltd | Transport & logistics | 2026 |
| Soul Adventure Limited | Education | 2017 |
| Southcote Bess SPV Ltd | Manufacturing | 2022 |
| Spacious Ltd | Information & communication | 2013 |
| Sparklebelle's Secrets Limited | Other services | 2024 |
| Speed Bird Investment Limited | Financial services | 2020 |
| Speedcut Contractors Ltd | Construction | 2001 |
| Spherical Films Ltd | Information & communication | 2009 |
| Spires Bridging Finance Limited | Financial services | 2016 |
| SPM Tyre Centre Limited | Wholesale & retail | 2026 |
| Spoon and Bowl Limited | Hospitality | 2025 |
| Springhill Homes Ltd | Construction | 2021 |
| Squarebox Investing Ltd | Households | 2022 |
| SR Nexg Limited | Information & communication | 2026 |
| ST Anne's (Wantage) Management Limited | Households | 2012 |
| ST Anne's Mews (Wantage) Management Company Limited | Households | 2008 |
| ST. Helens Mill Residents Company Limited | Households | 1982 |
| ST. James Place (Church Cowley) Management Company Ltd | Households | 2007 |
| ST. Margarets Court (Oxford) Residents Company Limited | Households | 1984 |
| Stack Optimise Ltd | Information & communication | 2023 |
| Staincross House Management Company Limited | Households | 1975 |
| Start to Thrive Ltd | Professional & scientific | 2020 |
| Statmite Limited | Real estate | 1989 |
| Stavco Construction Limited | Construction | 2001 |
| Sterling Foot Clinic Ltd | Health & social care | 2023 |
| Sterling Quality Support Limited | Health & social care | 2014 |
| Steve Cross Properties Limited | Real estate | 2007 |
| Steve on Lights Ltd | Professional & scientific | 2018 |
| Steve Ward Auto's Limited | Wholesale & retail | 2003 |
| Steve’S Jobs Multi-Services Limited | Other services | 2024 |
| Stoneworld (Oxfordshire) Limited | Manufacturing | 2002 |