| S & W Partnership | | 2001 |
| S E Bell Agri Food Limited | Professional & scientific | 2016 |
| S J Griffiths and Sons Ltd | Construction | 2024 |
| S.J. Plant Services Ltd | Manufacturing | 2004 |
| S2SEARCH Ltd | Information & communication | 2022 |
| Saddles Worldwide Limited | Wholesale & retail | 2019 |
| Sail and Sport Limited | Wholesale & retail | 2020 |
| Sally Brown Specialist Advisory Services Limited | Professional & scientific | 2013 |
| Samuel Robson Fine Art Limited | Arts & recreation | 2004 |
| Sarah Bousfield Design Limited | Professional & scientific | 2025 |
| Sarah Harding Interiors Limited | Wholesale & retail | 2004 |
| Saville Court (Oakham) Management Company Limited | Households | 2008 |
| Savvi Travel Ltd | Administrative & support | 2011 |
| Saytelco Ltd | Information & communication | 2023 |
| SC Consultants Limited | Professional & scientific | 2012 |
| Scape Creative Ltd | Administrative & support | 2013 |
| Schmusic Ltd | Administrative & support | 2025 |
| SD & GL Properties Limited | Real estate | 2022 |
| SE7EN Marketing Ltd | Information & communication | 2025 |
| Sea Asset Ltd | Real estate | 2014 |
| Sea Lotus Services Ltd | Real estate | 2016 |
| Sebae Ltd | Information & communication | 2018 |
| Second Tour Transition CIC | Education | 2025 |
| Securlock Limited | Construction | 2007 |
| Seegrove Limited | Professional & scientific | 2026 |
| Sefton Homes Ltd | Real estate | 2020 |
| Selfpoint 2020 Limited | Information & communication | 2019 |
| Senseal Limited | Construction | 2000 |
| Sensetec Limited | Administrative & support | 2025 |
| Sensorsone Limited | Wholesale & retail | 2006 |
| Sentance Technology Ltd | Information & communication | 2025 |
| Sentura Group Holdings Ltd | Financial services | 2019 |
| Sentura Group Ltd | Wholesale & retail | 2014 |
| Serious Security Limited | Administrative & support | 2010 |
| Serious Security Logistics Limited | Construction | 2015 |
| Service Hope CIC | Other services | 2026 |
| Seven Oceans Corp. Ltd | Professional & scientific | 2011 |
| SH Consultation Services Ltd | Arts & recreation | 2025 |
| Shacklewell Limited | Arts & recreation | 2013 |
| Shadow of the Gardener Ltd | Administrative & support | 2019 |
| Shang HAI 88 Limited | Hospitality | 2021 |
| Sheikh and Associates Ltd | Health & social care | 2024 |
| Sherpa Lounge 91 Limited | Hospitality | 2019 |
| Sherwood Ecology & Sustainability Ltd | Professional & scientific | 2022 |
| Shosha KOI Limited | Wholesale & retail | 2023 |
| Showmens Land Developments Company Limited | Construction | 2004 |
| Siddard Clothing Ltd | Wholesale & retail | 2025 |
| Sierra Medical Ltd | Information & communication | 2021 |
| Signal Care UK Limited | Health & social care | 2025 |
| Signs and Graphx Ltd | Wholesale & retail | 2011 |
| Silva BED Ltd | Agriculture & fishing | 2021 |
| Silverwood Farms Limited | Agriculture & fishing | 1995 |
| Simandf Services Ltd | Professional & scientific | 2021 |
| Simply Divine Wellbeing C.I.C. | Health & social care | 2022 |
| Sira Plumbing and Heating Limited | Construction | 2021 |
| Site Supplies Limited | Construction | 2013 |
| SJB Tractors Limited | Wholesale & retail | 2004 |
| Sjeglobal Ltd | Wholesale & retail | 2022 |
| SJN Builders Limited | Construction | 2001 |
| Slamcore Limited | Information & communication | 2016 |
| Slater Walker Limited | Agriculture & fishing | 2022 |
| Sloeberry Spirits Ltd. | Manufacturing | 2012 |
| SLW Blue Sky Living Limited | Real estate | 2025 |
| SLW Sunrise Property Group Limited | Real estate | 2025 |
| Smart Startup Solutions Ltd | Information & communication | 2025 |
| Smart-Steps Consultancy Ltd | Education | 2021 |
| Smith Eliot Financial Management Limited | Financial services | 2009 |
| Smith’S Plumbing and Heating Rutland Ltd | Construction | 2025 |
| Smorgasbord Business Ltd | Professional & scientific | 2018 |
| Snowdrop Homecare Rutland Ltd | Health & social care | 2019 |
| SOLAR1ST Ltd | Professional & scientific | 2023 |
| Somm EYE Care Limited | Health & social care | 2017 |
| Somm Real Estate Ltd | Real estate | 2019 |
| Sorrel Health Ltd | Health & social care | 2021 |
| SOURCE11 Limited | Information & communication | 2021 |
| Southbourne Retreats Limited | Real estate | 2024 |
| Southview Fencing Ltd | Construction | 2025 |
| SP Welding & Fabrication Ltd | Manufacturing | 2012 |
| Spencer Property Holdings Limited | Real estate | 2016 |
| Spinney Top Ltd | Financial services | 2024 |
| Spires (Langham) Management Company Limited | Households | 2001 |
| Sport USA Limited | Other services | 2017 |
| Sport USA Nigeria France Franchise Limited | Education | 2025 |
| Sport USA Poland Limited | Education | 2023 |
| Sportsrooms Limited | Administrative & support | 2015 |
| Springboard Commercial Limited | Professional & scientific | 2026 |
| Squirrel Internet Ltd | Information & communication | 2020 |
| Ssma Property Ltd | Real estate | 2021 |
| ST Legal Consulting Limited | Professional & scientific | 2022 |
| Stamford Fine Art Limited | Wholesale & retail | 2014 |
| Stamford Road Consulting Limited | Professional & scientific | 2021 |
| Stamford Stonecraft Ltd | Construction | 2016 |
| Stamworth Ltd | Professional & scientific | 2023 |
| Stanberry and Co Limited | Professional & scientific | 2013 |
| Stara Cuisine Limited | Hospitality | 2018 |
| Station Court (2004 Management) Limited | Households | 2004 |
| Steadfold Ltd | Construction | 2024 |
| Steele Group Limited | Real estate | 2015 |
| Stefa Hart Designs Ltd | Other services | 2024 |
| Stefa Hart Interiors Ltd | Administrative & support | 2024 |