| ST Austell Bay Wheels Limited | Wholesale & retail | 2015 |
| ST Austell BID | Public administration | 2012 |
| ST Austell Handyman Ltd | Construction | 2023 |
| ST Austell Healthcare Group (Mevagissey) Limited | Health & social care | 2020 |
| ST Austell Healthcare Group (PCN) Limited | Health & social care | 2020 |
| ST Austell Leisure Ltd | Arts & recreation | 2019 |
| ST Austell Power Limited | Extraterritorial | 2018 |
| ST Austell Properties Limited | Real estate | 2025 |
| ST Austell Rugby Football Club Limited | Arts & recreation | 2016 |
| ST Austell Turkish Barber Ltd | Other services | 2022 |
| ST Beauty and Spa Ltd | Other services | 2025 |
| ST Developments (Cornwall ) Limited | Construction | 2017 |
| ST EWE Affordable Homes Limited | Real estate | 2008 |
| ST Goran CLT Ltd | Hospitality | 2013 |
| ST Piran Community Builds Limited | Construction | 2024 |
| ST Piran Timber Frames Ltd | Construction | 2023 |
| ST. Austell Bay Ferries Limited | Transport & logistics | 2015 |
| ST. Austell Brewery Property Company Limited | Real estate | 2015 |
| ST. Austell Garden Machinery Limited | Manufacturing | 2003 |
| ST. Austell Nails and Spa Ltd | Construction | 2024 |
| Stages Theatre Arts Ltd | Arts & recreation | 2026 |
| Stak - ST Austell Community Kitchen | Health & social care | 2011 |
| Stamfordian Advisory Limited | Financial services | 2021 |
| Star Leisure Cornwall Limited | Hospitality | 2011 |
| Star Property Cornwall Limited | Real estate | 2020 |
| Start Key (Office Machines) Ltd | Administrative & support | 2008 |
| Staustellbayclassics Ltd | Wholesale & retail | 2024 |
| Staustelltrading Limited | Hospitality | 2024 |
| Stephen Gulyas Rail Limited | Construction | 2017 |
| Streamline Maintenance SW Ltd | Construction | 2022 |
| Stride Knows Ltd | Information & communication | 2026 |
| Stuart Nixon Bookkeeping Ltd | Professional & scientific | 2023 |
| Studio 4 Dance CIC | Arts & recreation | 2020 |
| Studio 60 Kernow Limited | Administrative & support | 2024 |
| Studio Nine Cornwall Ltd | Other services | 2022 |
| Studiyo Design Ltd | Professional & scientific | 2019 |
| Style Glaze (SW) Limited | Construction | 2009 |
| Success Sculptors Ltd | Administrative & support | 2025 |
| SUL Education Limited | Education | 1980 |
| Sun and Shade Ltd | Wholesale & retail | 2023 |
| Super Smith Bros Ltd | Information & communication | 2014 |
| Surechange Property Management Limited | Real estate | 1990 |
| Sureflow Mechanical and Electrical Services Limited | Construction | 2008 |
| Surf Hire Newquay Limited | Administrative & support | 2018 |
| Survey Dimensions Ltd | Construction | 2018 |
| Sustainable Luxury Boutiques Limited | Hospitality | 2025 |
| Sustainable Pathways Consulting Ltd | Professional & scientific | 2022 |
| Sustainable-Furniture (UK) Limited | Wholesale & retail | 2007 |
| SV Scaffolding Ltd | Construction | 2025 |
| Sweet GEO Services Ltd | Professional & scientific | 2023 |
| Sweet Geological Services Limited | Administrative & support | 2018 |
| Sylvias Emporium LLP | | 2015 |
| T C J Osborne Limited | Wholesale & retail | 2011 |
| T J (Roche) Ltd | Hospitality | 2010 |
| T J Captain Ltd | Administrative & support | 2025 |
| T Yeoman Architecture Ltd | Professional & scientific | 2023 |
| T. K. Deakin Limited | Manufacturing | 2009 |
| T.J. Baily Ltd | Construction | 2017 |
| T.J.P. Business Consultants Limited | Real estate | 1987 |
| TA Connections UK Ltd | Hospitality | 2016 |
| Table 16 Ltd | Hospitality | 2025 |
| Tada Services Ltd | Administrative & support | 2022 |
| TAI CHI Elements Ltd | Information & communication | 2012 |
| Tamar Management Company (ST Austell) Limited | Extraterritorial | 2016 |
| Taneberrow Limited | Manufacturing | 1994 |
| Taoist Cultural Arts Association | Other services | 2003 |
| Target GEO Limited | Professional & scientific | 2018 |
| Tcgtradein Ltd | Wholesale & retail | 2023 |
| Tea & Jones Ltd | Professional & scientific | 2013 |
| Team Kernow Limited | Arts & recreation | 2009 |
| Tebes Global Limited | Wholesale & retail | 2025 |
| Ted's Light CIC | Health & social care | 2019 |
| Teddington Appliance Controls Limited | Manufacturing | 2006 |
| Teddington Controls Limited | Professional & scientific | 1954 |
| Teddington Electronics Limited | Manufacturing | 2006 |
| Teddington Systems Limited | Extraterritorial | 2006 |
| TEE Accounts Limited | Professional & scientific | 2015 |
| TEE Properties Limited | Real estate | 2018 |
| TEN Squared AI Limited | Information & communication | 2024 |
| Texstyle Clothing Ltd | Wholesale & retail | 2026 |
| Tfortunehouse Ltd | Hospitality | 2025 |
| Thalassa Exploration Ltd. | Professional & scientific | 2015 |
| Thanks ITS Vintage Limited | Wholesale & retail | 2025 |
| That Tint GUY Limited | Wholesale & retail | 2021 |
| That Wrap GUY Ltd | Wholesale & retail | 2022 |
| THE Abcc Properties Ltd | Real estate | 2023 |
| THE Annex, Whitemoor Limited | Hospitality | 2026 |
| THE Barley Sheaf at Gorran Ltd | Hospitality | 2024 |
| THE Blue HUT Mevagissey Ltd | Hospitality | 2022 |
| THE Carpet Shop (Newquay) Ltd | Wholesale & retail | 2019 |
| THE Clay Haven CIC | Wholesale & retail | 2026 |
| THE Comms Pro Limited | Professional & scientific | 2024 |
| THE Cornish Arms Management Company Limited | Households | 2019 |
| THE Cornish Cloud Limited | Information & communication | 2025 |
| THE Cornish Cricket Company Limited | Arts & recreation | 2009 |
| THE Cornish Diamond Co Ltd | Wholesale & retail | 2025 |
| THE Cornish Embassy Limited | Hospitality | 2014 |
| THE Cornish Loft Hatch Ltd | Hospitality | 2022 |
| THE Cornish Tractor Club Limited | Health & social care | 1998 |
| THE Cornwall Bicycle Project CIC | Education | 2020 |