| Stellmacher Aviation Ltd | Administrative & support | 2017 |
| Stocco Connect Limited | Energy | 2020 |
| Stocken Hall Beef Ltd | Agriculture & fishing | 2013 |
| Stone Soup Solutions Limited | Professional & scientific | 2025 |
| Stonecraft Rutland Limited | Construction | 2004 |
| Stoneville Investments Limited | Real estate | 2012 |
| Strategic HR Support Ltd | Administrative & support | 2010 |
| Strategicedge Advisory Ltd | Professional & scientific | 2023 |
| Strategus Limited | Professional & scientific | 1998 |
| Stratus Bytes Limited | Professional & scientific | 2017 |
| Stratus Luxe Limited | Arts & recreation | 2025 |
| Stretton Wood Estate Management Company Limited | Real estate | 2002 |
| Strive-Now Limited | Professional & scientific | 2025 |
| Student Storage Experts (UK) Limited | Administrative & support | 2014 |
| Subject Object Limited | Arts & recreation | 2022 |
| SUE Mayne Ltd | Health & social care | 2025 |
| Sullivan Beare Limited | Construction | 2009 |
| Summario Ltd | Information & communication | 2024 |
| Sunrise Language Services Limited | Professional & scientific | 2009 |
| Super Ceramic Services Limited | Construction | 1984 |
| Supplied by Green-Wood Ltd | Manufacturing | 2025 |
| Support & Connections Oakham Ltd | Health & social care | 2024 |
| Surdi Domum Group Ltd | Administrative & support | 2017 |
| Sure Life Care Limited | Administrative & support | 2020 |
| Surface Generation Limited | Manufacturing | 2002 |
| Sustain Developments Ltd | Information & communication | 2025 |
| Sustainable Business School Ltd | Education | 2026 |
| Sweet Boxing Gear Limited | Manufacturing | 2020 |
| Swoopairsports Limited | Wholesale & retail | 2025 |
| T D Johnson Funerals Limited | Other services | 2024 |
| T.S.A (Oakham) Ltd | Professional & scientific | 2013 |
| Tacoparty Ltd | Hospitality | 2020 |
| Tagg's Cafe Limited | Hospitality | 2024 |
| Tailor BIO Ltd | Professional & scientific | 2019 |
| Tait Associates Limited | Administrative & support | 2011 |
| Talkcoms Limited | Information & communication | 2016 |
| Tamric Management Limited | Wholesale & retail | 2022 |
| Tamu App Ltd | Information & communication | 2017 |
| TAS Education and Medical Ltd | Health & social care | 2023 |
| Task Agency Limited | Professional & scientific | 2023 |
| Tauran Limited | Wholesale & retail | 2024 |
| Taylor Made Solutions (UK) Limited | Information & communication | 1998 |
| Taylor-Made Dog Training Ltd | Other services | 2025 |
| TCS Foods Ltd | Hospitality | 2023 |
| Teamsoft UK Limited | Wholesale & retail | 2025 |
| Technelec Limited | Manufacturing | 1992 |
| Tee-Total Golf Ltd | Arts & recreation | 2025 |
| Tenax Debt Recovery Ltd | Administrative & support | 2025 |
| Tennis Groups Ltd | Education | 2022 |
| Tetworth Horse Events Limited | Arts & recreation | 2026 |
| Tetworth Horse Trials Limited | Arts & recreation | 2026 |
| Texon Limited | Administrative & support | 1999 |
| Textbook Teachers Recruitment and Education Services Limited | Education | 2002 |
| THE Admiral Hornblower Limited | Hospitality | 2014 |
| THE AG50 Company Community Interest Company | Arts & recreation | 2024 |
| THE Amusement Device Industry Standard Certificate of Competency Board Limited | Professional & scientific | 2022 |
| THE ARK Association | Education | 2011 |
| THE Billion Pound Company Limited | Financial services | 2025 |
| THE Botanical Clothing Company Ltd | Wholesale & retail | 2023 |
| THE Canned Land Property Company Ltd | Manufacturing | 2014 |
| THE Caring Company Rutland Ltd | Health & social care | 2012 |
| THE Church Planting Initiative | Other services | 2000 |
| THE Courthouse Melton Mowbray Limited | Households | 2022 |
| THE Courts (Uppingham) Management Company Limited | Real estate | 2003 |
| THE Craft Sausage Company Ltd. | Manufacturing | 2017 |
| THE Culmak Shaving Brush Co. Limited | Manufacturing | 1995 |
| THE Culshaw Partnership LLP | | 2020 |
| THE Cyclists of Stamford Community Interest Company | Arts & recreation | 2021 |
| THE Cyclists Studio Limited | Wholesale & retail | 2026 |
| THE DGS Collective Limited | Extraterritorial | 2025 |
| THE Douglas Kerry Group Limited | Hospitality | 2024 |
| THE Farmer Project CIC | Agriculture & fishing | 2025 |
| THE FAT Trout Limited | Hospitality | 2025 |
| THE Garage Management Company Limited | Households | 2014 |
| THE Gardener's Forge Ltd | Manufacturing | 2025 |
| THE George and Dragon Seaton Ltd | Hospitality | 2026 |
| THE George Inn Oakham (Holdco) Ltd | Financial services | 2022 |
| THE George Inn Oakham Ltd | Hospitality | 2022 |
| THE Haberdashery FAN Limited | Wholesale & retail | 2023 |
| THE Heavenly Bake Company Ltd | Manufacturing | 2015 |
| THE Hiden Collective Ltd | Wholesale & retail | 2020 |
| THE House of Medusa Ltd | Wholesale & retail | 2021 |
| THE Inclusively Exclusive Treat Company Limited | Wholesale & retail | 2019 |
| THE Inky Frog Picture Company Limited | Arts & recreation | 1999 |
| THE K Holdings Group Ltd | Hospitality | 2026 |
| THE Kitchen (Spalding) Limited | Hospitality | 2012 |
| THE Learning Link CIC | Education | 2025 |
| THE Leisure Development Partnership | | 2001 |
| THE Life Cadets Ltd | Other services | 2025 |
| THE Little Fabric Shop Ltd | Wholesale & retail | 2014 |
| THE Little IP Company Ltd | Professional & scientific | 2024 |
| THE Lonely Pixel Limited | Information & communication | 2018 |
| THE Lord Nelson in Oakham Ltd | Hospitality | 2024 |
| THE Lyndon Property Company Limited | Construction | 2018 |
| THE Mortgage Checker Limited | Extraterritorial | 2022 |
| THE Natural Limestone Company Limited | Construction | 2012 |
| THE Nursery Toolbox Ltd | Information & communication | 2026 |
| THE Oakham Aesthetics Klinic Limited | Health & social care | 2022 |
| THE Oakham Handyman Limited | Construction | 2026 |
| THE Old Hall Stables Management Company Limited | Households | 2010 |