| Russell Recycling Limited | | 1978 |
| Rutland Motors House Ltd | Wholesale & retail | 2025 |
| S & H Barton Property Limited | Real estate | 2005 |
| S and L Brown Limited | Manufacturing | 2003 |
| S J Scaffolding (Lincoln) Ltd. | Construction | 1992 |
| S Jackson & Sons (Holme) | Agriculture & fishing | 1982 |
| S.C. & T. Limited | Professional & scientific | 2004 |
| S.F. Handson (Wainfleet) Limited | Wholesale & retail | 1986 |
| S.J. Loveley Limited | Construction | 2006 |
| S.R. Drilling Services (HDD) Ltd | Construction | 2025 |
| S.T. Belton Limited | Hospitality | 1938 |
| S.T. Hopper (Boston) Limited | Wholesale & retail | 1983 |
| Salway and Wright (Lincs) Ltd | Administrative & support | 2004 |
| Sayer Fencing Limited | Administrative & support | 2005 |
| Scorror Farms Limited | Agriculture & fishing | 2001 |
| Scotts Commercials (Lincoln) Limited | Wholesale & retail | 2007 |
| Scratchmaster Smart Systems Ltd | Wholesale & retail | 2007 |
| Sea Glass PR Limited | Professional & scientific | 2006 |
| Seacroft Properties Limited | Financial services | 1995 |
| Sebastian Moretti Comptuters Limited | Wholesale & retail | 2025 |
| Secker Welding Limited | Manufacturing | 2005 |
| Selman Marine Design Limited | Professional & scientific | 1996 |
| Setcops Farm Limited | Hospitality | 2007 |
| Shareteq Limited | Wholesale & retail | 2005 |
| Sharman Burgess Limited | Real estate | 1995 |
| Sheardown Farms Limited | Agriculture & fishing | 1999 |
| Shree-Iman Professionals Limited | Administrative & support | 2003 |
| Sibjon Builders Limited | Construction | 2003 |
| Silver ASH Developments Limited | Real estate | 1998 |
| Silverwood Money Management Limited | Administrative & support | 2001 |
| Sivi Holdings Limited | Professional & scientific | 2008 |
| SJ Stanberry & Sons Limited | Construction | 2001 |
| Skegness Day Centre Limited | Other services | 2003 |
| Skegness Natureland Limited | Arts & recreation | 2006 |
| Skegness Specsavers Limited | Wholesale & retail | 1998 |
| Skegness Springs Limited | Manufacturing | 1974 |
| Skegness Visionplus Limited | Wholesale & retail | 1998 |
| Skill Serve 2000 Limited | Professional & scientific | 1999 |
| Skywalker Productions Limited | Arts & recreation | 2006 |
| Sleaford Leisure Limited | Agriculture & fishing | 2000 |
| Sleaford Property Developments Limited | Construction | 2007 |
| Slingsby Marsden & Co LLP | | 2001 |
| Smithcem K'5 Limited | Manufacturing | 2004 |
| Sodanch Properties Limited | Hospitality | 2025 |
| Solid Spot Ltd | Administrative & support | 2023 |
| Solutions Reality Limited | Information & communication | 2003 |
| South Holland Plant Centre Limited | Wholesale & retail | 2003 |
| South Lincs Storage Limited | Real estate | 2021 |
| South Links Breakers Limited | Wholesale & retail | 2017 |
| Spa Landscaping (Woodhall) Limited | Administrative & support | 2004 |
| Spalding Osteopathic Practice Limited | Health & social care | 2006 |
| Spalding Pallets Limited | Administrative & support | 1996 |
| SPE Contracting Ltd | Construction | 2003 |
| Specialist Cheeses Limited | Wholesale & retail | 2003 |
| Spenbark Developments Limited | Real estate | 2004 |
| Spilsby Jewellers Limited | Wholesale & retail | 2006 |
| Spraysure Limited | Manufacturing | 2006 |
| Springfield Park Properties (Grantham) Limited | Real estate | 1993 |
| Springfield Park Properties Limited | Real estate | 1993 |
| Square Square Circle Ltd | Manufacturing | 2018 |
| ST. Hugh's School (Woodhall Spa) Limited | Education | 1964 |
| Stanhope House Leisure Limited | Arts & recreation | 2001 |
| Stanhope Leisure (Guernsey) Ltd | Arts & recreation | 2006 |
| Stephen Barnett Associates Limited | Administrative & support | 1996 |
| Stephen Hewitt Limited | Health & social care | 2003 |
| Stephen Powell Limited | Professional & scientific | 1979 |
| Sterland Holdings Limited | Financial services | 2025 |
| Stirling Process Engineering Ltd | Professional & scientific | 2010 |
| Strategic Limited | Extraterritorial | 1996 |
| Strictly Legal Limited | Information & communication | 2002 |
| Strombolis Ltd | Professional & scientific | 2004 |
| STS Civils Limited | Construction | 2003 |
| SUE Larder Limited | Other services | 2002 |
| Sunnycentral Property Management Limited | Households | 2000 |
| Sunnydecks Limited | Manufacturing | 2003 |
| Super Duper YES Limited | Wholesale & retail | 2017 |
| Supervite Pet Foods Limited | Professional & scientific | 1980 |
| Sutherland Consulting (UK) Ltd | Construction | 2005 |
| Swayfields (Skelton) Limited | Professional & scientific | 1996 |
| Sweetstyle and Co | Agriculture & fishing | 1977 |
| Systemize (UK) Limited | Information & communication | 1998 |
| Syston Park Farm Shop Limited | Wholesale & retail | 2005 |
| T G Developments Limited | Extraterritorial | 1982 |
| T W Logistics Limited | Manufacturing | 1996 |
| T. Gibson & Sons (Stamford) Limited | | 1960 |
| T. Kingswood Mortgage Services Limited | Financial services | 2005 |
| T.A. Burley Pharmacy Limited | Health & social care | 2005 |
| Tasty Curry Ltd | Hospitality | 2021 |
| Telesat Communications Limited | Information & communication | 2003 |
| Tennyson Tyres Ltd | Wholesale & retail | 2003 |
| THE Boars Head Louth Ltd | Hospitality | 2018 |
| THE Cheal House Farm Partnership | | 1989 |
| THE Compleat Gardener Limited | Administrative & support | 2004 |
| THE Deepings Caravan Park Ltd. | Hospitality | 2025 |
| THE Elms Leisure Park Limited | Wholesale & retail | 2007 |
| THE Gunner's Store Ltd | Wholesale & retail | 2002 |
| THE Lincoln Eastgate Hotel Limited | Hospitality | 2001 |
| THE Old Bain Management Company Limited | Households | 1990 |
| THE Rocking Horse Nursery Stamford Limited | Education | 2003 |
| THE Sessions House Spalding CIC | Arts & recreation | 2025 |