| SEE Communications CIC | Health & social care | 2016 |
| Seeker Developments Limited | Real estate | 2018 |
| Sefton Developments & Restoration Limited | Real estate | 1989 |
| Seing Limited | Professional & scientific | 2011 |
| Select Sites Limited | Other services | 1955 |
| Self Energising Coupling Company Limited | Manufacturing | 2004 |
| Self Storage Weaver Ltd | Real estate | 2025 |
| Sell OUR Motorhome Ltd | Wholesale & retail | 2020 |
| Sell OUR Caravan Limited | Wholesale & retail | 2021 |
| Sen-Go Adventures Ltd | Health & social care | 2024 |
| Send to Sleep Limited | Health & social care | 2026 |
| Sensible Air Conditioning Limited | Construction | 2012 |
| Sensory Project Limited | Health & social care | 2017 |
| Serendipity Creatives CIC | Health & social care | 2025 |
| Serenity Studios Cheshire Ltd | Arts & recreation | 2023 |
| SEW in Style Ltd | Information & communication | 2016 |
| SF Analyticon Limited | Professional & scientific | 2013 |
| SFC Capital Ltd | Financial services | 2012 |
| SG (Cheshire) Limited | Real estate | 1999 |
| SGM Enterprises Limited | Information & communication | 2000 |
| Shanxietyx Ltd | Professional & scientific | 2026 |
| Shape Shape Ltd | Arts & recreation | 2025 |
| Shaped Edge Construction & Scaffold Ltd | Construction | 2026 |
| Shawn Ganguly & Co Ltd | Real estate | 2025 |
| SHE CAN Scale Limited | Professional & scientific | 2025 |
| Shed & Field Ltd | Real estate | 2020 |
| Shellmech Limited | Construction | 2002 |
| Shentonfield Properties LLP | | 2009 |
| Shire Design Systems Limited | Administrative & support | 2010 |
| Shiv News Ltd | Wholesale & retail | 2019 |
| Shoppy Local Limited | Information & communication | 2015 |
| Shroomwell UK Ltd | Health & social care | 2025 |
| Siam Trade Ltd | Wholesale & retail | 2026 |
| Sian Gouldstone Occupational Therapy Services Ltd | Other services | 2012 |
| Siano Promotions Limited | Arts & recreation | 2020 |
| Siedemjeden Architekci Ltd | Professional & scientific | 2015 |
| SIGMA42 Limited | Information & communication | 2018 |
| Sign in Plus Ltd | Information & communication | 2025 |
| Signal and Gain Ltd | Professional & scientific | 2020 |
| Signature Kitchens & Bathrooms Limited | Wholesale & retail | 2009 |
| Signs of Cheshire Limited | Manufacturing | 2003 |
| Silva Tech Servicing Ltd | Wholesale & retail | 2025 |
| Silver Birch Shutters and Blinds Limited | Construction | 2020 |
| Silver Lady Music Ltd | Information & communication | 2025 |
| Simpleanit Ltd | Professional & scientific | 2022 |
| Simply Assemble Services Ltd | Construction | 2021 |
| Simply Plates Ltd | Manufacturing | 2021 |
| Simplydiag Network Limited | Professional & scientific | 2019 |
| Simplyhelpingseniors Limited | Health & social care | 2019 |
| Simpson Learning Disabilities & Neuro Navigating Consultancy Ltd | Public administration | 2026 |
| Simurg Mobility Technologies Ltd | Information & communication | 2026 |
| Sincap Limited | Real estate | 2016 |
| SIR Leslie Martin Nursery Ltd | Education | 2020 |
| Siriem Global Limited | Professional & scientific | 2026 |
| Site Axis International Ltd | Construction | 2024 |
| Sitesource Recruitment Ltd | Administrative & support | 2025 |
| Siteworks Hire Limited | Construction | 2025 |
| Sitpro Limited | Information & communication | 2019 |
| SIX Hats Solutions Ltd | Information & communication | 2020 |
| Six-Chairmen Limited | Information & communication | 2015 |
| SIX65 Solutions Limited | Real estate | 2014 |
| SJ Rushe Ltd | Professional & scientific | 2023 |
| SJF Data Consultancy Ltd | Information & communication | 2025 |
| Skateboardstickers.Com Ltd | Wholesale & retail | 2014 |
| SKN Inc Ltd | Other services | 2024 |
| SKS Convenience Stores Limited | Wholesale & retail | 2019 |
| Skt&Sons Ltd | Manufacturing | 2025 |
| Skycrest Holdings Ltd | Financial services | 2022 |
| Skyline Insights Ltd | Professional & scientific | 2025 |
| Slabs Crisps Limited | Wholesale & retail | 2021 |
| SLC Utilities & Groundworks Limited | Construction | 2021 |
| Slim HAT Ltd | Manufacturing | 2025 |
| Slns Group of Companies Limited | Real estate | 2024 |
| SM Hughes Consulting Ltd | Professional & scientific | 2020 |
| Small Street Markets Ltd | Administrative & support | 2022 |
| Smart Clinic (Health) Limited | Health & social care | 2018 |
| Smart Journey Limited | Real estate | 2018 |
| Smart Psychology Services Limited | Health & social care | 2024 |
| Smart Rail Services Limited | Other services | 2009 |
| Smartbooksuk Ltd | Professional & scientific | 2021 |
| Smartechnics Limited | Wholesale & retail | 2016 |
| Smarterile Limited | Manufacturing | 2025 |
| Smartsize IT Ltd | Information & communication | 2013 |
| SMB Designs (Cheshire) Ltd | Professional & scientific | 2016 |
| SMH (Americas) MMS Ltd | Professional & scientific | 2023 |
| Smod Distribution Ltd | Wholesale & retail | 2024 |
| SMR Trading Limited | Wholesale & retail | 2019 |
| SMS Mevac UK Limited | Manufacturing | 1954 |
| Snjconsultancy Ltd | Professional & scientific | 2025 |
| Snms Properties Limited | Real estate | 2026 |
| Snoozle Clothing Ltd | Manufacturing | 2024 |
| Snowdrop Cafe Limited | Hospitality | 2023 |
| Snugnights UK LLP | | 2005 |
| Snugnorthwich Ltd | Hospitality | 2025 |
| SO Glamorous Limited | Other services | 2010 |
| Socatots (Mid-Cheshire) Limited | Arts & recreation | 2005 |
| Social Capital Ltd | Professional & scientific | 2019 |
| Social Media Executive Ltd | Professional & scientific | 2018 |
| Socialfix Consulting Ltd | Professional & scientific | 2025 |
| Soilsense Ltd | Agriculture & fishing | 2019 |