| Seawitch Theatre Ltd | Arts & recreation | 2023 |
| Selveyn Investments Ltd | Real estate | 2022 |
| Semmens Developments Limited | Construction | 2018 |
| Semmens Haulage Limited | Transport & logistics | 2022 |
| Senara Agency Ltd | Arts & recreation | 2023 |
| Sennen Beach Ltd | Extraterritorial | 2010 |
| Sennen Surf Company Ltd | Wholesale & retail | 2015 |
| Sennen Surf Lodge Ltd | Hospitality | 2026 |
| Sequoia Lodge Limited | Construction | 2002 |
| Seren Lior Law Ltd | Professional & scientific | 2022 |
| Shaded the Label Ltd | Wholesale & retail | 2023 |
| Shanghai Penzance Trading Ltd | Wholesale & retail | 2024 |
| Shifting Horizons Community Interest Company | Education | 2009 |
| Shoreline Pizzeria Cornwall Ltd | Hospitality | 2021 |
| Shuttleworth Consultants Ltd | Professional & scientific | 2021 |
| Silvertip Asset Management Limited | Real estate | 2021 |
| Silvertip Capital Advisors Limited | Administrative & support | 2023 |
| Simon Allen Sculptor Ltd | Wholesale & retail | 2023 |
| Simon Earp Building Contractors Limited | Construction | 2008 |
| Sinogroup Limited | Professional & scientific | 2016 |
| SIP Social Events Ltd | Hospitality | 2026 |
| SJP Foot & Ankle Surgery (Cornwall) Limited | Health & social care | 2014 |
| Skellett Medical Services Ltd | Health & social care | 2020 |
| Skewjack Surf Village Ltd | Wholesale & retail | 2014 |
| Skewjax Limited | Hospitality | 2020 |
| SKT Restaurant Limited | Hospitality | 2023 |
| Skydance Media Limited | Professional & scientific | 2013 |
| Slam Holdings Ltd | Agriculture & fishing | 2019 |
| Small AXE Medical Limited | Health & social care | 2026 |
| Smart Artist Ltd | Real estate | 2024 |
| SMV Holdings Limited | Administrative & support | 2023 |
| Sneakertroop Ltd | Wholesale & retail | 2021 |
| Solo Freight Limited | Transport & logistics | 2012 |
| South West Design and Mechanical Ltd | Professional & scientific | 2023 |
| South West Heating Solutions Limited | Construction | 2013 |
| South West Marine Ltd | Manufacturing | 2022 |
| South West Play Limited | Manufacturing | 2020 |
| South West Shellfish Limited | Agriculture & fishing | 2022 |
| South West Tyre Services Ltd | Wholesale & retail | 2025 |
| South West Wedding Photography Limited | Other services | 2018 |
| Southern Comfort Penzance Ltd | Hospitality | 2004 |
| Sowena Limited | Professional & scientific | 2019 |
| Space for YOU Limited | Health & social care | 2009 |
| Spaldylou Limited | Hospitality | 2017 |
| Sparkerling Ltd | Administrative & support | 2015 |
| Spot-M Ltd | Administrative & support | 2008 |
| Sprayrend South West Limited | Construction | 2015 |
| Square Stories Limited | Arts & recreation | 2017 |
| Square Tortoise Ltd | Arts & recreation | 2020 |
| Sshgrp Ltd | Professional & scientific | 2024 |
| Ssri Limited | Financial services | 2026 |
| ST Buryan Agricultural Preservation Ltd | Administrative & support | 2017 |
| ST Clare Medical Group Limited | Health & social care | 2018 |
| ST Cyrs Ltd | Hospitality | 2008 |
| ST Ives Bay Fishermens' CIC | Health & social care | 2026 |
| ST Ives Motor Company Limited | Wholesale & retail | 2007 |
| ST Ives Safety Nets Limited | Construction | 2007 |
| ST James Court ST Ives Residents Management Company Limited | Other services | 2009 |
| ST Just DIY & Gardening Ltd | Wholesale & retail | 2024 |
| ST Just RFC Limited | Hospitality | 2012 |
| ST Justin Limited | Manufacturing | 2002 |
| ST Michael's Mews (Penzance) Limited | Households | 2016 |
| ST. EIA Limited | Hospitality | 2021 |
| ST. Ives Restaurants Limited | Hospitality | 2011 |
| ST. Just & District Community Sports Association Limited | Arts & recreation | 2002 |
| ST. Just Garage Limited | Wholesale & retail | 2005 |
| ST. KEW Accountancy Ltd. | Professional & scientific | 2012 |
| ST. Paul's House Management Company Limited | Extraterritorial | 1986 |
| ST. Pirans Court Management Company Limited | Other services | 2001 |
| St.Just Community A.B.C. Ltd | Other services | 2009 |
| Stacey Mann Estates Ltd | Real estate | 2018 |
| Starscraper Limited | Information & communication | 2008 |
| Startzone Limited | Real estate | 1990 |
| Stelliferous Kernow Limited | Arts & recreation | 2021 |
| Stelliferous Limited | Arts & recreation | 2017 |
| Stennack Parc Limited | Households | 1990 |
| Stephen Green Exhibits Ltd. | Professional & scientific | 2019 |
| Steve Tanner Fotographics Limited | Professional & scientific | 2003 |
| Stevens Fishing and Marine Services Limited | Agriculture & fishing | 2022 |
| Still Harbour Ltd | Hospitality | 2024 |
| Stimson & Tieken Surveyors Ltd | Professional & scientific | 2026 |
| Stirlings Limited | Wholesale & retail | 2002 |
| Stjustanddistrict CIC | Other services | 2026 |
| Stoke Hill Paddocks Limited | Real estate | 2022 |
| Stoked Ever Since Ltd | Information & communication | 2014 |
| Stone Cross Developments & Construction Limited | Construction | 2003 |
| Stone's Taxis Limited | Transport & logistics | 1998 |
| Strawberry Fields (Crowlas) Management Company Limited | Construction | 2010 |
| Stronger Studio Ltd | Arts & recreation | 2024 |
| Studio Lightwoods Ltd | Wholesale & retail | 2020 |
| Studio West Architects Limited | Professional & scientific | 2014 |
| Studioliveuk Limited | Information & communication | 2019 |
| Studiostays Eastbourne Ltd | Hospitality | 2024 |
| Stunts U K Limited | Arts & recreation | 2002 |
| Styleaire Ltd | Manufacturing | 2023 |
| Success Investment Group Ltd | Professional & scientific | 2015 |
| SUE Penna Ltd | Financial services | 2022 |
| Sullivan's (SW) Limited | Construction | 2018 |
| Sunbeam Jackie Ltd | Manufacturing | 2019 |
| Sundance Developments Limited | Construction | 2001 |