| Stamper Agricultural Limited | Administrative & support | 2007 |
| STAN66 Ltd | Transport & logistics | 2019 |
| Stanley Resources (UK) Limited | Professional & scientific | 2012 |
| Star Auto Services Ltd | Wholesale & retail | 2008 |
| Star Mews (Melbourn) Management Company Limited | Households | 2024 |
| Star Services (Cambs) Ltd | Construction | 2015 |
| Star Universal Heat Sealers Ltd | Manufacturing | 2026 |
| Stardust Dance Academy Limited | Arts & recreation | 2023 |
| Stardust Entertainment Limited | Education | 2020 |
| Stark Compliance Group Limited | Administrative & support | 2025 |
| Starlight Event Management Ltd | Administrative & support | 2020 |
| Starswift Ltd | Information & communication | 2007 |
| Startup & Small Marketing Ltd | Professional & scientific | 2018 |
| Station Gardens Management Company Limited | Households | 1987 |
| Staughton Estate Farms Limited | Agriculture & fishing | 1978 |
| Staybright Cladding Services Limited | Administrative & support | 2020 |
| Stedavlo Limited | Real estate | 2023 |
| Stellar CYO Healthcare Limited | Health & social care | 2024 |
| Steorra Ltd | Wholesale & retail | 2006 |
| Step 2 Recruit Ltd | Extraterritorial | 2022 |
| Stephen Austin Limited | Professional & scientific | 2024 |
| Stephen Cole Surfacing Limited | Construction | 2014 |
| Stephens 39 Investments Limited | Financial services | 2023 |
| Sterry Drums Ltd | Manufacturing | 2024 |
| Steve Punter Medical Ltd | Health & social care | 2024 |
| Steve's Car Sales and Servicing Limited | Wholesale & retail | 2021 |
| Stevelin Motorcycles Limited | Wholesale & retail | 2010 |
| Stevens & SON Plumbing & Heating Solutions Limited | Construction | 2008 |
| Stiles and Co Training and Consultancy Ltd | Professional & scientific | 2026 |
| Stock DOC Limited | Professional & scientific | 2017 |
| Stomart Limited | Wholesale & retail | 2024 |
| Stone Signal Digital Ltd | Administrative & support | 2023 |
| Stonegrove Contractors Limited | Construction | 2026 |
| Stones Auto Compliance Limited | Administrative & support | 2025 |
| Storiello Construction Projects Limited | Construction | 2016 |
| Stormshield Property Maintenance Ltd | Construction | 2024 |
| Stothard Cost Planning Limited | Construction | 2019 |
| Stowe Management Limited | Real estate | 2014 |
| Strangemunkey Ltd | Wholesale & retail | 2024 |
| Streamline Building Services Limited | Construction | 2002 |
| Streamline Consulting Limited | Information & communication | 2017 |
| Street Safe Limited | Financial services | 2025 |
| Streetly Hall Farm Limited | Agriculture & fishing | 2010 |
| Stringer Aviation Ltd | Professional & scientific | 2023 |
| Structus HR Limited | Administrative & support | 2025 |
| STS Contracting Limited | Manufacturing | 2026 |
| Stuart & Verity Limited | Households | 1974 |
| Stuart Bryant Services Limited | Construction | 2013 |
| Studio Artemis Ltd | Wholesale & retail | 2024 |
| Studio Devere Limited | Administrative & support | 2023 |
| Studio Micallef Ltd | Professional & scientific | 2015 |
| Stukeley Business Centre Limited | Professional & scientific | 1988 |
| Stukeley MOT and Repair Centre Ltd | Wholesale & retail | 2017 |
| Style Home Improvements Ltd. | Construction | 2009 |
| Subsoldierz Ltd | Arts & recreation | 2026 |
| Subsurface Measurement Technology Ltd | Construction | 2021 |
| Summerfield Ventures Ltd. | Hospitality | 2014 |
| Summers & Hitz Enterprises Ltd | Wholesale & retail | 2025 |
| Summit Property Services (UK) Ltd | Construction | 2014 |
| Summit Training Ltd | Arts & recreation | 2026 |
| Sun and Snow Slovenia Ltd | Hospitality | 2016 |
| Sun Risk Management Ltd | Professional & scientific | 2002 |
| Sundog Software Limited | Information & communication | 2015 |
| Sundown Products Limited | Manufacturing | 1999 |
| Sunfun Group Ltd | Administrative & support | 2023 |
| Sunfun Holidays Ltd | Administrative & support | 2023 |
| Sunfun International Ltd | Administrative & support | 2023 |
| Sunfun Luxury Travel (Group) Ltd | Administrative & support | 2023 |
| Sunfun Luxury Travel Ltd | Administrative & support | 2023 |
| Sunny Solar Renewables Limited | Construction | 2025 |
| Sunnyside Group Ltd | Health & social care | 2023 |
| Sunquest Services Limited | Professional & scientific | 1993 |
| Sunshine Designs Ltd | Construction | 2022 |
| Super EV Ltd | Energy | 2021 |
| Superior Finish Ltd | Administrative & support | 2002 |
| Superior Surfaces Limited | Administrative & support | 2009 |
| Supply & Demand Limited | Administrative & support | 2008 |
| Support Cambridgeshire Ltd. | Education | 2006 |
| Supported Steps (Cambridgeshire) Ltd | Health & social care | 2021 |
| Suprclean Ltd | Administrative & support | 2022 |
| Surface Science Applications Ltd | Manufacturing | 2025 |
| Surgikal Ltd | Health & social care | 2019 |
| Surprised Stare Games Limited | Information & communication | 1999 |
| Sustainex Structures Ltd | Construction | 2025 |
| Suta Logistic Ltd | Transport & logistics | 2025 |
| Suzanvictor Ltd | Wholesale & retail | 2025 |
| SVA Couriers Ltd | Transport & logistics | 2022 |
| SW Motorcare Ltd | Wholesale & retail | 2015 |
| Swales (Guns) Limited | Wholesale & retail | 2002 |
| Swanne London Ltd | Other services | 2025 |
| Swarmed Ltd | Information & communication | 2023 |
| Swavelo Group Ltd | Wholesale & retail | 2026 |
| Sweeping TOM Ltd | Administrative & support | 2023 |
| Sweet BUT Twisted Ltd | Manufacturing | 2024 |
| Sweet Taste of America Ltd | Hospitality | 2019 |
| SWF Contracting Services Ltd | Administrative & support | 2024 |
| Swift Gym Solutions Ltd | Manufacturing | 2019 |
| Swift Network Services Ltd | Information & communication | 2023 |
| Swiftswing Limited | Health & social care | 2009 |
| Swim Streamlined Limited | Education | 2024 |