| Scientific Arab Forum Limited | Professional & scientific | 2022 |
| Scientific Committee on Antarctic Research | Professional & scientific | 2008 |
| Scientific Concepts Limited | Information & communication | 2001 |
| Scientific Consulting Limited | Professional & scientific | 2014 |
| Scientific Vacuum Systems Ltd | Manufacturing | 1990 |
| Scientifica Books Limited | Wholesale & retail | 2007 |
| Scilacci Ltd | Wholesale & retail | 2024 |
| Scintacor Limited | Manufacturing | 1983 |
| Scintilla.Ai Ltd | Information & communication | 2018 |
| Scion Blockchain Ltd. | Information & communication | 2020 |
| Scip Consulting Ltd | Administrative & support | 2026 |
| Scitech Horizons Limited | Information & communication | 2005 |
| Scitribe Ltd | Professional & scientific | 2017 |
| SCL Communications Ltd | Information & communication | 1998 |
| SCL Ventures Ltd | Information & communication | 2014 |
| SCN Property Management Limited | Hospitality | 2004 |
| Scoopy-Doo Ltd | Manufacturing | 2024 |
| Scoott Limited | Extraterritorial | 2024 |
| Score Band Limited | Wholesale & retail | 2018 |
| Score Draw (Receivables) Ltd | Extraterritorial | 2015 |
| Score Draw (Retail) Ltd | Extraterritorial | 2015 |
| Scotch Hill Ltd | Hospitality | 2023 |
| Scotcher People Limited | Professional & scientific | 2023 |
| Scotsdale Fordham Limited | Construction | 2017 |
| Scotsdale Nursery and Garden Centre Limited | Wholesale & retail | 1964 |
| Scott Group Ltd | Wholesale & retail | 2025 |
| Scott Reiter Painting and Decorating Ltd | Construction | 2026 |
| Scott's OIL Field Services Ltd | Manufacturing | 2019 |
| Scott-Pollock Limited | Wholesale & retail | 2018 |
| Scott-Pollock Projects Limited | Professional & scientific | 2022 |
| Screens and Graphics Limited | Manufacturing | 1975 |
| Screenware Associates Limited | Information & communication | 1995 |
| Scrimpers Limited | Administrative & support | 1997 |
| Scroll Ltd | Information & communication | 2018 |
| Scrubs for Cambridgeshire C.I.C. | Manufacturing | 2021 |
| Scruffs Hairdressing Ltd | Other services | 2006 |
| Scruffs Holding Limited | Financial services | 2026 |
| SCS Consulting (Cambridge) Ltd | Professional & scientific | 2008 |
| Scsr Soft Solutions Ltd | Information & communication | 2016 |
| Scudamores Punting Company Limited | Transport & logistics | 1993 |
| Sculin International Ltd | Education | 2024 |
| Sculpt Ltd | Construction | 2016 |
| Scurry Ltd | Hospitality | 2023 |
| Scurrybus CIC | Transport & logistics | 2024 |
| Scww 2 Limited | Real estate | 2019 |
| Scww 3 Limited | Real estate | 2019 |
| SD Info Ltd | Information & communication | 2025 |
| SDC Hosting and Support Ltd | Information & communication | 2016 |
| Sdee Limited | Wholesale & retail | 2024 |
| SDG4 Global Citizens Ltd | Information & communication | 2023 |
| SDI Group PLC | Professional & scientific | 2007 |
| Sdld Limited | Extraterritorial | 2018 |
| SDR Cyber Security Ltd | Information & communication | 2024 |
| Sdrj Consulting Limited | Information & communication | 2014 |
| SDS Racing Ltd | Arts & recreation | 2024 |
| SDS Therapeutics Limited | Professional & scientific | 2020 |
| Sea Fortune Safety Product Ltd | Extraterritorial | 2014 |
| Sea Shell Club Limited | Hospitality | 2010 |
| Sea Steward Limited | Hospitality | 2017 |
| Sea.Lam Archive Limited | Wholesale & retail | 2023 |
| Seabass Productions Limited | Information & communication | 2009 |
| Seabra 75 Engineering Ltd | Manufacturing | 2026 |
| Seacap SA Limited | Professional & scientific | 2024 |
| Seadream Marine Trading Co., Ltd | Manufacturing | 2026 |
| Seafapac Marine Service Co., Ltd | Wholesale & retail | 2023 |
| Seafen Caelus Limited | Professional & scientific | 2018 |
| Seagull International Trading Co., Ltd | Wholesale & retail | 2023 |
| Sean Klein Media Limited | Professional & scientific | 2013 |
| Sean Mayes Consulting Limited | Professional & scientific | 2011 |
| Sean O'Connor's Windows Games Ltd | Information & communication | 2005 |
| Seapeq Limited | Extraterritorial | 2005 |
| Seaqual Limited | Information & communication | 2026 |
| Search Professionals Limited | Information & communication | 2008 |
| Searching Finance Limited | Information & communication | 2009 |
| Searching for Rainbows Ltd | Financial services | 2025 |
| Searo Labs Ltd | Professional & scientific | 2022 |
| Sears Advanced Composites Ltd | Manufacturing | 2019 |
| Seashores Trade Services Ltd | Wholesale & retail | 2023 |
| Seasons Consulting (International) Limited | Professional & scientific | 2018 |
| SEB House Ltd | Real estate | 2018 |
| Seb.Vdv Ltd | Health & social care | 2025 |
| Seba VIP Aviation Ltd | Manufacturing | 2025 |
| Seban Composites Ltd | Manufacturing | 2022 |
| Sebavionstian Ltd | Manufacturing | 2024 |
| Sebo - Transport Ltd | Administrative & support | 2025 |
| Second Therapeutics Ltd | Professional & scientific | 2025 |
| Second Warren Residents Association Limited(The) | Households | 1986 |
| Secret Alchemy Ltd | Health & social care | 2021 |
| Secretary Ltd | Information & communication | 2026 |
| Secure Oasis Home Limited | Health & social care | 2025 |
| Secure Thingz Limited | Information & communication | 2014 |
| Securebrook Limited | Information & communication | 1982 |
| Secured IT Ltd | Information & communication | 2006 |
| Securevents & Logistics Ltd | Administrative & support | 2025 |
| Security 4 Locations Ltd | Administrative & support | 2011 |
| Securiwise Limited | Administrative & support | 2017 |
| Sedge Ltd | Information & communication | 2025 |
| Sedna Yatcilik Limited | Professional & scientific | 2025 |
| SEE Cambridge Differently Limited | Administrative & support | 2017 |
| Seebeck 163 Limited | Financial services | 2019 |