| Seacrest Investments Limited | Real estate | 1994 |
| Seascope Trading Limited | Real estate | 2004 |
| Seatons Regency Windows Limited | Real estate | 2003 |
| Seaview (Seaton) Limited | Real estate | 1984 |
| Seaways (Paignton) Management Company Limited | Households | 2007 |
| Sector Leisure Limited | | 1987 |
| Seddon Estate Agents LLP | | 2002 |
| Sedgewell Enterprises Limited | | 1988 |
| Seeing | Administrative & support | 2005 |
| Seer Properties Investments Ltd | Real estate | 2017 |
| Seethru (Torquay) Limited | Construction | 2004 |
| Serrurerie Objatoise Limited | Manufacturing | 1999 |
| Sevomile Limited | Other services | 1990 |
| Sevs Solution Ltd | Manufacturing | 2018 |
| Seymour Horwell Limited | Wholesale & retail | 1983 |
| Shaka South West Ltd | Hospitality | 2025 |
| Sharpenson Limited | Information & communication | 2006 |
| Shaveley Developments Limited | Real estate | 1993 |
| Shaveley Properties (UK) Limited | Real estate | 2004 |
| Shirlet Limited | Real estate | 2004 |
| SID Little Scaffolding Ltd | Administrative & support | 2001 |
| Sidmarc Limited | Construction | 2003 |
| Sidmouth Hotels Limited | Hospitality | 2000 |
| Sidmouth Software Limited | Information & communication | 1998 |
| Sidwell Street Motors Limited | Extraterritorial | 1971 |
| Sigma Electrical Ltd. | Manufacturing | 2003 |
| Signs South-West Limited | Manufacturing | 2002 |
| Silo Rieder Ltd | Transport & logistics | 2021 |
| Silver Lion Jewellers (Newton Abbot) Limited | Wholesale & retail | 2003 |
| Silver Skies Consulting Limited | Professional & scientific | 2007 |
| Silverarm Limited | Professional & scientific | 2006 |
| Silverline Water Softeners Limited | Manufacturing | 1996 |
| Silverquants Limited | Professional & scientific | 1997 |
| Silverstone Care Ltd | Health & social care | 2024 |
| Simon Cannon Limited | Construction | 1995 |
| Simon Money Garden Services Limited | Other services | 2003 |
| Simon Rigden Associates Limited | Professional & scientific | 2007 |
| Simpletest Company Limited | Professional & scientific | 1992 |
| SIX Flat Management Limited | Households | 1985 |
| SJA Accountants Limited | Professional & scientific | 1999 |
| Skyblue Aero Services Limited | Transport & logistics | 2004 |
| SLC Garage Limited | Wholesale & retail | 2007 |
| Smakner Ltd | Other services | 2024 |
| Smgdc Limited | Administrative & support | 2001 |
| Smugglers Hotel Ltd | Hospitality | 2025 |
| Sodor Geosciences Limited | Professional & scientific | 2018 |
| Solace Laboratories Ltd | Information & communication | 2018 |
| Solvenco Ltd | Other services | 2023 |
| Soniadeleonhealthcare Limited | Public administration | 2025 |
| Sortimo International Limited | Wholesale & retail | 1998 |
| Soundpad Limited | Wholesale & retail | 2003 |
| Sourceasia Limited | Professional & scientific | 2004 |
| South Coast Services Exmouth Limited | Wholesale & retail | 1996 |
| South Devon Contractors Limited | | 1983 |
| South Devon Developments Limited | Construction | 2005 |
| South Devon Railway Trust | Transport & logistics | 1974 |
| South East Asia Enterprises Limited | Hospitality | 2004 |
| South Hams Online Limited | Professional & scientific | 2013 |
| South West Contracts Limited | Transport & logistics | 2004 |
| South West Environmental Parks Limited | Arts & recreation | 1964 |
| South West Events Limited | Professional & scientific | 2002 |
| South West Instrumentation Limited | Professional & scientific | 2000 |
| South West Land Limited | Real estate | 1978 |
| South West Mediation Limited | Professional & scientific | 2003 |
| South West Music Limited | | 1983 |
| South West Timber Haulage Limited | Transport & logistics | 2007 |
| South West Wholesale Limited | Construction | 1997 |
| South West ZOO Enterprises Limited | Wholesale & retail | 1990 |
| South Western Construction Limited | | 1982 |
| South Western Developments Limited | Professional & scientific | 2003 |
| South-West Training Ltd | Other services | 2018 |
| Southbower Limited | Agriculture & fishing | 2004 |
| Southdown 4 X 4 Products Limited | Manufacturing | 2003 |
| Southern Foundations & Piling Ltd | Construction | 2020 |
| Southernhay Motors Limited | Wholesale & retail | 2005 |
| Southfork A.T.B. Ltd | Wholesale & retail | 2005 |
| Southoria Estates Limited | Real estate | 1908 |
| Spectrum Design Limited | | 1970 |
| Speedway Car Sales Limited | Wholesale & retail | 2024 |
| Speedway Garage MOT and Service Centre Limited | Wholesale & retail | 2019 |
| Spence Crane Hire Limited | Administrative & support | 2005 |
| Spence Cranes Limited | Administrative & support | 2005 |
| Spenlec Limited | Construction | 2002 |
| Spice Lounge (Devon) Ltd | Hospitality | 2021 |
| Spider Events Limited | Other services | 2004 |
| Sporting Classics (Sherborne) Limited | Wholesale & retail | 2002 |
| Spreacombe Estate Co Limited | Hospitality | 1977 |
| Spring Mist Ltd | Information & communication | 2006 |
| Spring Willow Limited | Information & communication | 2021 |
| Springboard Group Limited | Administrative & support | 2004 |
| Sprint Print Co.Limited | Manufacturing | 1971 |
| ST & AM Dennis Ltd | Agriculture & fishing | 2002 |
| ST John's Court Management (Teignmouth) Limited | Real estate | 2002 |
| ST Petrock's (Exeter) Limited | Hospitality | 2001 |
| ST. Leonards Court (Exeter) Limited | Households | 1984 |
| ST. Wilfrid's School (Exeter) Limited | Education | 1988 |
| Stacked (South West) Limited | Hospitality | 2022 |
| Stanley House (Teignmouth) Limited | Households | 2003 |
| Stapleton Pet Supplies Limited | Wholesale & retail | 2008 |
| Star Lettings and Property Management Limited | Real estate | 2004 |