| Skoob Books Limited | Wholesale & retail | 2016 |
| Sky Wonders Ltd | Wholesale & retail | 2024 |
| Skys Data Consultancy Ltd | Information & communication | 2023 |
| SM8RT Ltd | Manufacturing | 2022 |
| SMB Signature Ltd | Health & social care | 2026 |
| Smith & Co Moves Ltd | Water & waste | 2026 |
| Smith & Fletcher Limited | Professional & scientific | 2013 |
| Smoothy Delivery Ltd | Transport & logistics | 2026 |
| Snowdon Property Management Ltd. | Real estate | 2009 |
| Snuggs & Murray Ltd | Construction | 2022 |
| Social Tapestry Ltd | Professional & scientific | 2019 |
| Softlivingco Ltd | Manufacturing | 2026 |
| Software Defined Storage Limited | Professional & scientific | 2009 |
| Soleluna Pizza 2 Ltd | Hospitality | 2021 |
| Soleluna Pizza Franchising Ltd | Hospitality | 2021 |
| Solo Ventures Limited | Professional & scientific | 2004 |
| Solutions Management Limited | Administrative & support | 2025 |
| Some Coffee Ltd | Wholesale & retail | 2024 |
| Somos Group Limited | Professional & scientific | 2025 |
| Sorella Hair Abingdon Ltd | Other services | 2023 |
| South Moreton Boxing and Fitness Club CIC | Arts & recreation | 2026 |
| South Oxfordshire Plastering Limited | Construction | 2018 |
| South West Cyber Security Cluster | Information & communication | 2017 |
| Space Catapult Limited | Extraterritorial | 2025 |
| Space Catapult Services Limited | Extraterritorial | 2025 |
| Space Odyssey Real Estate Ltd | Real estate | 2026 |
| Space Power Ltd | Energy | 2019 |
| Sparkle Play Oxfordshire Ltd | Wholesale & retail | 2023 |
| Spartan Protection Services Ltd | Administrative & support | 2022 |
| Speedy Restorations Ltd | Wholesale & retail | 2026 |
| Spice Application Systems Limited | Manufacturing | 1999 |
| Spottitt Ltd | Information & communication | 2017 |
| Sprayxpert Ltd | Wholesale & retail | 2026 |
| Springbuild Construction Limited | Construction | 2015 |
| SPS Dynatech Limited | Information & communication | 2023 |
| Sql-R Ltd | Information & communication | 2017 |
| Square Wave Technology Ltd | Information & communication | 2022 |
| SRF Properties 2 Ltd | Real estate | 2024 |
| Srilak Tech Limited | Information & communication | 2013 |
| Srivastava IV Ltd | Real estate | 2025 |
| SSA Asset Limited | Construction | 2017 |
| Sskm Store Limited | Wholesale & retail | 2025 |
| SSS (London) Holdings Ltd | Real estate | 2022 |
| ST Construction Ltd. | Construction | 2017 |
| Stalefish Software Limited | Information & communication | 2011 |
| Stampup Ltd | Wholesale & retail | 2024 |
| Stan Language Services Ltd | Professional & scientific | 2026 |
| Standers Global Limited | Wholesale & retail | 2024 |
| Star Spice Ltd | Hospitality | 2025 |
| Starlight Images Ltd | Information & communication | 2023 |
| Starnet Comms Limited | Hospitality | 2019 |
| Staspack Procurement Services Limited | Administrative & support | 2023 |
| Static Control Components (Europe) Limited | Wholesale & retail | 1993 |
| Station Flooring (UK) Ltd | Construction | 2012 |
| Station Flooring Holdings Ltd | Financial services | 2024 |
| Station Tyres & Service Centre Limited | Extraterritorial | 2015 |
| Staycation INV Ltd | Real estate | 2025 |
| Staying in Style Ltd | Real estate | 2017 |
| Stella's Cleaning Services Ltd | Administrative & support | 2021 |
| Stellar Solutions Aerospace Limited | Professional & scientific | 2003 |
| Stephane Ltd | Hospitality | 2017 |
| Stephena Limited | Professional & scientific | 2021 |
| Sterling Construction Management Services Ltd | Construction | 2020 |
| Stfc Innovations Limited | Administrative & support | 2002 |
| Stickman Communications Limited | Health & social care | 2019 |
| Strata Fire Protection Ltd | Public administration | 2026 |
| Striden Estates Limited | Real estate | 2024 |
| Stryde Holdings Ltd | Financial services | 2024 |
| Studio 91 Music Ltd | Manufacturing | 2017 |
| Studio Amma Ltd | Professional & scientific | 2025 |
| Studio Stefanova Ltd | Professional & scientific | 2025 |
| Suite Press Ltd | Professional & scientific | 2024 |
| Sulaymonov Watch Company Limited | Wholesale & retail | 2019 |
| SUM Competitions Limited | Arts & recreation | 2023 |
| Sumeria Solutions Ltd | Information & communication | 2026 |
| Sun Lounge Didcot Ltd | Other services | 2023 |
| Sunray Alpha Ltd | Public administration | 2024 |
| Super Saver Eats Ltd | Wholesale & retail | 2023 |
| Superdad Ltd | Real estate | 2024 |
| Sure Shutters & Blinds Limited | Wholesale & retail | 2003 |
| Surendo Limited | Health & social care | 2018 |
| Surrounding Counties Ltd | Construction | 2022 |
| Suvegasoft Limited | Information & communication | 2004 |
| SV Sagger Ltd | Real estate | 2024 |
| Swan Shop Ltd | Real estate | 2025 |
| Swaran Property Development Ltd | Construction | 2026 |
| Sweets by ADA Limited | Manufacturing | 2023 |
| Swimming FUN Limited | Wholesale & retail | 2017 |
| Symeqs Limited | Manufacturing | 2017 |
| T C Water Services Limited | Water & waste | 2011 |
| T Jackman Catering Ltd | Hospitality | 2010 |
| T Mcgill Property Maintenance Ltd | Construction | 2022 |
| T-Key Homes Ltd | Real estate | 2023 |
| Tadley Consulting Ltd | Professional & scientific | 2020 |
| Tamar Technical Limited | Administrative & support | 2015 |
| Tame & Wild Active Ltd | Wholesale & retail | 2026 |
| Tammyk Ltd | Health & social care | 2015 |
| Tanfinity Ltd | Wholesale & retail | 2025 |
| Tanghulu Limited | Hospitality | 2022 |
| Tappan Wealth Management Ltd | Financial services | 2020 |