| Sharp Informatics Consulting Ltd | Information & communication | 2023 |
| Sharp on Fire Compliance Limited | Public administration | 2019 |
| Shaw Commercial Properties (IVE 15) Limited | Real estate | 1999 |
| Shaw Services (Cambridge) Limited | Real estate | 1968 |
| Shaws of Cambridge (BD20) Limited | Transport & logistics | 1982 |
| Shaws of Cambridge (BL19) Limited | Administrative & support | 1983 |
| Shaws of Cambridge (EH) Limited | Real estate | 2013 |
| Shaws of Cambridge (EQ20) Limited | Real estate | 1998 |
| Shaws of Cambridge (GR) Limited | Administrative & support | 2013 |
| Shaws of Cambridge (OP115) Limited | Real estate | 1983 |
| Shelford Plastering Limited | Construction | 2001 |
| Shell Estates UK Ltd | Administrative & support | 2015 |
| Shepherd Print Limited | Manufacturing | 2010 |
| Sheppey Energy Limited | Professional & scientific | 2016 |
| Sherwood Engines Limited | Construction | 2014 |
| Shiftology HQ Limited | Information & communication | 2022 |
| Shine & Co ELY Ltd | Real estate | 2017 |
| Shiny Armour Limited | Professional & scientific | 2021 |
| Shooting Image Limited | Professional & scientific | 2008 |
| Shoreline Trading Limited | Construction | 2014 |
| Short by Design Limited | Information & communication | 2026 |
| Shrewd Finance Ltd | Financial services | 2014 |
| SI Walker Studios Ltd | Other services | 2023 |
| SI. Marine Services Limited | Health & social care | 2011 |
| SID Bibby Turf & Landscaping Limited | Administrative & support | 2002 |
| Sigma Embroidery and Printing Ltd | Wholesale & retail | 2019 |
| Signal and Scale Ltd | Information & communication | 2026 |
| Signet Apartments Limited | Hospitality | 2006 |
| Silvain Construction Limited | Manufacturing | 2025 |
| Silver Birch Pet Jets Limited | Other services | 2013 |
| Silver Oak Coffee Ltd | Wholesale & retail | 2013 |
| Silverkey Stays Ltd | Real estate | 2026 |
| Silversmokerings Ltd | Information & communication | 2013 |
| Simfani Ltd | Real estate | 2023 |
| Simon Eggleton Draughting Services Limited | Information & communication | 2003 |
| Simon Mckay PR Limited | Professional & scientific | 2003 |
| Simper Phillips Accountants Limited | Professional & scientific | 2015 |
| Sims Carpentry and Joinery Limited | Construction | 2024 |
| Singer 24/7 Care Ltd | Health & social care | 2015 |
| Singing Attitude Ltd | Education | 2026 |
| Sinova Healthcare Ltd | Wholesale & retail | 2023 |
| Sirphy Traders Ltd | Wholesale & retail | 2025 |
| Siya Odedra Ltd | Wholesale & retail | 2025 |
| SJ & EA Property Ltd | Real estate | 2020 |
| Skin Soul Ltd | Health & social care | 2016 |
| Sleek Soul Ltd | Wholesale & retail | 2025 |
| Sloops Limited | Wholesale & retail | 2015 |
| SM Engineering (ELY) Limited | Manufacturing | 2015 |
| Smart Rock Limited | Information & communication | 2007 |
| Smartcare Analytics Ltd | Manufacturing | 2015 |
| SMH Brickwork Ltd | Manufacturing | 2026 |
| Smilez 12 Ltd | Public administration | 2020 |
| Smoom Skin Ltd | Manufacturing | 2021 |
| Smoothfinishbuilders Ltd | Construction | 2025 |
| Software Reference Limited | Information & communication | 2006 |
| Software Verify Limited | Information & communication | 1994 |
| Soham Land Ltd | Real estate | 2026 |
| Soham Launderettes Limited | Other services | 1970 |
| Soham Nail Spa Ltd | Other services | 2023 |
| Soham Old Comrades Club | Health & social care | 2011 |
| Soham Stores Limited | Wholesale & retail | 2019 |
| Soham Town Rangers Football & Social Club Ltd | Arts & recreation | 2022 |
| Solamend Ltd | Manufacturing | 2026 |
| Sole Scaffolding Limited | Construction | 2020 |
| Solomans Developments Ltd | Construction | 2022 |
| Something Generic Ltd | Administrative & support | 2025 |
| Something Special (ELY) Limited | Wholesale & retail | 2003 |
| Soniqs Limited | Manufacturing | 2008 |
| Sooko Ltd | Manufacturing | 2015 |
| Sooty's Properties Limited | Real estate | 1974 |
| Sophie's Great WAR Tours Ltd | Administrative & support | 2013 |
| Sopris Ltd | Professional & scientific | 2009 |
| Soroptimist International Limited | Extraterritorial | 1985 |
| Sorted Content Ltd | Information & communication | 2025 |
| Sorted Fitness Limited | Wholesale & retail | 2017 |
| Souperstar Ltd | Manufacturing | 2018 |
| South Coast Powerboats Ltd | Wholesale & retail | 2018 |
| South East Boiler Services Ltd | Administrative & support | 2019 |
| SP K9 Therapy Ltd | Other services | 2019 |
| Spa ELY Limited | Other services | 2005 |
| Spanish Tax Forms Limited | Administrative & support | 2008 |
| Sparta Cars Ltd | Wholesale & retail | 2024 |
| Spearhead Marketing Limited | Agriculture & fishing | 1999 |
| Specialty Measurement Bidco Limited | Financial services | 2020 |
| Specialty Measurement Holdco Limited | Financial services | 2020 |
| Spectra Displays Limited | Manufacturing | 1989 |
| Spectral Measurement Limited | Extraterritorial | 2019 |
| Spectre Auto Ltd | Wholesale & retail | 2026 |
| Sphere Integrated Health Care Limited | Health & social care | 2005 |
| Spice Cuisine Limited | Hospitality | 2022 |
| Spiced Media Ltd | Information & communication | 2022 |
| Spinks Estates Limited | Real estate | 2015 |
| Spinney Abbey Ltd | Manufacturing | 2011 |
| Spitfire Management Limited | Professional & scientific | 2013 |
| Splash and Dash Creations Ltd | Arts & recreation | 2022 |
| Spot on Physio Clinic Ltd | Public administration | 2025 |
| Spotboard Limited | Information & communication | 2026 |
| Spray Solutions Building Ltd | Construction | 2017 |
| SR4 Homes Ltd | Real estate | 2019 |
| SR4 Mortgages Limited | Financial services | 2021 |