| Stag Holdings (South West) Ltd | Manufacturing | 2021 |
| Stamford Dining Limited | Hospitality | 2022 |
| Stamford Resin Ltd | Construction | 2026 |
| Stamford Resin Surfacing Ltd | Construction | 2024 |
| Standace Limited | Wholesale & retail | 1985 |
| Star IT Limited | Other services | 2008 |
| Star Linen Hire & Laundry Services Limited | Other services | 2014 |
| Star Property Assets Ltd | Financial services | 2025 |
| Star Refuse Collection Services Ltd | Water & waste | 2022 |
| Star Voice Ltd | Information & communication | 2015 |
| Starfish ST Ives Limited | Hospitality | 2024 |
| Stargazy FC CIC | Arts & recreation | 2023 |
| Starmech Limited | Wholesale & retail | 2009 |
| Stator Systems Worldwide Ltd | Manufacturing | 2022 |
| Stay ST Ives Ltd | Real estate | 2025 |
| Steel Logik Ltd | Manufacturing | 2022 |
| Stella & Co (UK) Ltd | Hospitality | 2016 |
| Stellar General Trading Limited | Wholesale & retail | 2024 |
| Stencil - Tech Franchising Limited | Manufacturing | 2021 |
| Stephen James Inns Ltd | Hospitality | 2023 |
| Stephen James Wines Limited | Wholesale & retail | 2025 |
| Steve Buttercase Ltd | Financial services | 2009 |
| Steve Jacklin Limited | Construction | 2012 |
| Stewart and Coleman Limited | Transport & logistics | 2024 |
| STG Rentals Limited | Real estate | 2025 |
| Still Standing Ltd | Professional & scientific | 2026 |
| Stone Advisory Limited | Financial services | 2023 |
| Stoneacre Properties Ltd | Construction | 2005 |
| Stop That Leak Limited | Other services | 2013 |
| Stormshield Home Improvements Ltd | Construction | 2025 |
| Strippers Flooring Ltd | Construction | 2021 |
| Stuart Nunn Mortgages LLP | | 2016 |
| Studio Formed Limited | Other services | 2025 |
| Studio Pegpa Ltd | Professional & scientific | 2022 |
| Studio Wyatt Ltd | Information & communication | 2019 |
| Sublime Precision Ltd | Manufacturing | 2026 |
| Suddenly on Sheaf Street Limited | Wholesale & retail | 2023 |
| Suddenly Publishing Limited | Information & communication | 2023 |
| SUE Parker Hall Psychotherapy Services Ltd | Health & social care | 2011 |
| Sumit (Company Secretary) Limited | Professional & scientific | 1998 |
| Summer Properties (Cambs) Ltd | Real estate | 2022 |
| Summit Scaffolding Ltd. | Construction | 2005 |
| Sunnyside Cleaners Ltd | Administrative & support | 2024 |
| Super Icon Limited | Information & communication | 2012 |
| Superior Finish Ceramics Ltd | Construction | 2019 |
| Superior Finish Contract Flooring Ltd | Administrative & support | 2015 |
| Supported Designs Ltd | Professional & scientific | 2021 |
| Surfhouse St.Ives CIC | Education | 2015 |
| Surj IT Specialists Ltd | Information & communication | 2007 |
| Sustainability Solved Ltd | Professional & scientific | 2022 |
| Swallow Regeneration Limited | Construction | 2018 |
| Swanky Drinks Limited | Wholesale & retail | 2025 |
| Sweet Socials Ltd | Information & communication | 2025 |
| Swift Catering Supplies Ltd | Wholesale & retail | 2003 |
| Swra Properties Ltd | Wholesale & retail | 2026 |
| Swynford Paddocks Stud Limited | Extraterritorial | 1984 |
| Sycamore Laundries Limited | Other services | 2020 |
| Symons Construction Limited | Construction | 2012 |
| Symons Retail Limited | Hospitality | 2011 |
| Systemsafe Limited | Manufacturing | 1999 |
| T & F Holdings Ltd | Real estate | 2020 |
| T J Briggs Ltd | Construction | 2014 |
| T Marsh Ltd | Mining & quarrying | 2002 |
| T W Landscaping Limited | Administrative & support | 2024 |
| T&T Private Hire Ltd | Transport & logistics | 2014 |
| T.C. Installations Limited | Professional & scientific | 1997 |
| T.J. Briggs and Sons Limited | Real estate | 1977 |
| T3E Solutions Ltd | Extraterritorial | 2026 |
| Tacconi Green & Co 6 Ltd | Professional & scientific | 2019 |
| Tacconi Green Payroll Ltd | Professional & scientific | 2014 |
| Tailx Limited | Wholesale & retail | 2025 |
| Talay Thai Limited | Hospitality | 2026 |
| Talent Availability Ltd | Administrative & support | 2023 |
| Tallie Incorporated Limited | Financial services | 2021 |
| Tandoori House Ltd | Hospitality | 2024 |
| TAS Estate Planning Ltd | Professional & scientific | 2025 |
| Tattersall Consultancy Ltd | Information & communication | 2022 |
| Taxation Advisory Xervices Limited | Professional & scientific | 2013 |
| Taytrev Investments Ltd | Households | 2024 |
| TCR Salons Limited | Other services | 2011 |
| TDM Automotive Limited | Wholesale & retail | 2019 |
| Team Cadence Investments Ltd | Real estate | 2024 |
| Team Cadence Ltd | Administrative & support | 2021 |
| Techybird Limited | Wholesale & retail | 2024 |
| Tedtan Limited | Administrative & support | 2011 |
| Tekstore Huntingdon Limited | Other services | 2026 |
| Tempest Photography Limited | Extraterritorial | 2004 |
| Tempest Travel Photography Limited | Professional & scientific | 2019 |
| Tendring Vineyard Limited | Agriculture & fishing | 2023 |
| Tent Government Limited | Real estate | 2002 |
| Teylu (ST Ives) Limited | Hospitality | 2021 |
| Teylu BOS Ltd | Wholesale & retail | 2022 |
| Thai Time Cornwall Limited | Hospitality | 2025 |
| THE 154 High Street Association | Hospitality | 1988 |
| THE Academy-Badminton for ALL Limited | Arts & recreation | 2009 |
| THE Badminton Academy Limited | Arts & recreation | 2009 |
| THE BAS Breakwell Charitable Trust Company | Health & social care | 2007 |
| THE Boom Group Ltd | Professional & scientific | 2022 |
| THE Bottle Bank Ltd | Wholesale & retail | 2021 |
| THE Brave Ones Ltd | Wholesale & retail | 2021 |