| Rosevear Meadows (Management) Limited | Households | 2020 |
| Rosevears Furnishers Ltd | Wholesale & retail | 2001 |
| Rototop UK Ltd | Wholesale & retail | 2025 |
| Rowett Property Investments Limited | Construction | 2025 |
| RTS Training Ltd | Education | 2025 |
| Rtsal Ltd | Administrative & support | 2020 |
| Run a Race Ltd. | Wholesale & retail | 2013 |
| Rustic Homes Ltd | Construction | 2026 |
| Rustic Property Ltd | Construction | 2026 |
| Rustikated Ltd | Education | 2021 |
| Rustique Hair Ltd | Other services | 2020 |
| S a UDY Ltd | Construction | 2024 |
| S D Sinnott Plastering Ltd | Construction | 2014 |
| S. Atwell Packaging Limited | Manufacturing | 1988 |
| S.H. Fiske Limited | Manufacturing | 1978 |
| SA & DP UDY Ltd | Construction | 2010 |
| SA Nails and Spa Ltd | Other services | 2024 |
| SAB Holdings Incorporated Limited | Financial services | 2023 |
| Sabiha Cakes Ltd | Wholesale & retail | 2026 |
| SAC Advisory Limited | Professional & scientific | 2025 |
| Safeland Executive Security Solutions Ltd | Administrative & support | 2024 |
| Safety in Design Limited | Professional & scientific | 2009 |
| Saint Austell Curry Ltd | Hospitality | 2026 |
| Salt and Stone Sports Therapy Ltd | Health & social care | 2025 |
| Salty Swims Community Interest Company | Arts & recreation | 2021 |
| Sandow Studio Ltd | Other services | 2025 |
| Sarah Wain Consultancy Services Ltd | Information & communication | 2010 |
| Sarahpshe CIC | Education | 2017 |
| Savigar Services Ltd | Professional & scientific | 2018 |
| SBR Electrical Limited | Construction | 2022 |
| Sburt Couriers Ltd | Transport & logistics | 2020 |
| Scholars Pulse Ltd | Education | 2025 |
| School of Dough CIC | Hospitality | 2024 |
| Scorpion SW Ltd | Wholesale & retail | 2026 |
| Sea Dogs Barbers Ltd | Other services | 2019 |
| Sea Road Residents' Association Ltd | Households | 1983 |
| Seadog IT Ltd | Information & communication | 2019 |
| Seakisses Limited | Wholesale & retail | 2014 |
| Sean Sullivan Your Local Roofer Ltd | Construction | 2014 |
| Seaside Bliss Ltd | Other services | 2024 |
| Seaview (South West) Limited | Professional & scientific | 2008 |
| Seaview Windows Doors Plastics Ltd | Construction | 2023 |
| Selkie Wines Ltd | Wholesale & retail | 2026 |
| Sensory Trust | Health & social care | 1993 |
| Sentors Kitchens Ltd | Manufacturing | 2021 |
| Sevencon Search Ltd | Administrative & support | 2020 |
| SG Project Consultancy Ltd | Construction | 2022 |
| SG Property Solutions Limited | Households | 2025 |
| SGA (ST Austell) Ltd | Professional & scientific | 2013 |
| Sheridan Magor Construction Ltd | Construction | 2026 |
| Shi'Oren Development Ltd | Education | 2025 |
| Shine With Aurum Ltd | Administrative & support | 2024 |
| Shio Cornwall Ltd | Hospitality | 2025 |
| Ship Inn Pentewan Ltd | Hospitality | 2021 |
| Shoreside Developments SW Ltd | Construction | 2026 |
| Shrimp & Starfish Ltd | Wholesale & retail | 2022 |
| Simply Accounting Online Limited | Professional & scientific | 2025 |
| Sirrah Developments Ltd | Construction | 2019 |
| SJ Milton Properties Ltd | Real estate | 2020 |
| SJ Thomas Electrical LLP | | 2025 |
| SJB Computer Consultants Ltd | Information & communication | 1999 |
| SJG (South West) Ltd | Construction | 2013 |
| Skindog Hardware Ltd | Wholesale & retail | 2017 |
| Skingley Sales Management Limited | Real estate | 1976 |
| Slappy's Ltd | Hospitality | 2024 |
| Smart Fitness (South West) Limited | Hospitality | 2019 |
| Smart Packaging Limited | Manufacturing | 2001 |
| Smart Turnaround Ltd | Professional & scientific | 2019 |
| Smit Associates Holdings Limited | Construction | 2022 |
| Smith & SON Plumbing Ltd | Construction | 2025 |
| Smithson Developments Ltd | Construction | 2019 |
| Smoke & Ember Catering Ltd | Hospitality | 2025 |
| Smss (Site Management Services Somerset) Limited | Professional & scientific | 2022 |
| Snowdon Retail (Launceston) Limited | Hospitality | 2015 |
| SNW Transport Limited | Wholesale & retail | 2023 |
| SOL Komfort Interiors Limited | Manufacturing | 2013 |
| Somertree Properties Limited | Real estate | 1999 |
| Sonstream Limited | Wholesale & retail | 2010 |
| South West BNG & Habitat Ltd | Agriculture & fishing | 2025 |
| South West Developments (Cornwall) Ltd | Construction | 2024 |
| South West Power Promotions Limited | Arts & recreation | 2016 |
| South West Stairs Ltd | Manufacturing | 2019 |
| South West Sweepers Ltd | Administrative & support | 2016 |
| South West Woodworking Ltd | Construction | 2023 |
| Southcoast Offshore Services Ltd | Professional & scientific | 2020 |
| Southwest Homecare Solutions Ltd | Health & social care | 2017 |
| Southwest Laser Training Academy Ltd | Education | 2025 |
| Southwesterly Deckchairs & Windbreaks Ltd | Wholesale & retail | 2021 |
| Spa Wetrooms Ltd | Construction | 2026 |
| Space Hair Studios Ltd | Other services | 2011 |
| Spearfishing Limited | Wholesale & retail | 2013 |
| Spike Fern Ltd | Arts & recreation | 2023 |
| Spirited Trawlers (BP) Limited | Agriculture & fishing | 2024 |
| Spitfire Design (UK) Limited | Wholesale & retail | 2000 |
| Spitfire Park Limited | Hospitality | 2022 |
| Splash Master Ltd | Administrative & support | 2025 |
| SPR Distribution Ltd | Wholesale & retail | 2024 |
| Springfield House (Bugle) Management Company Limited | Other services | 2009 |
| Spysquad Studios Ltd | Information & communication | 2025 |
| ST Austell Accountants Limited | Extraterritorial | 2009 |