| SJG Timber Ltd | Wholesale & retail | 2023 |
| SJM Consultants Ltd | Professional & scientific | 2025 |
| SJM Plymouth Ltd | Real estate | 2025 |
| SJN Construction Limited | Construction | 2017 |
| Sjpg Capital Ltd | Real estate | 2021 |
| Sjpg Ltd | Real estate | 2020 |
| SJS Wealth Management Limited | Financial services | 2011 |
| SK Electrical SW Ltd | Construction | 2018 |
| SK Holdings (Devon) Limited | Financial services | 2018 |
| SK Property & Development Ltd | Construction | 2019 |
| Skew Bridge Management Company Limited | Households | 1997 |
| SKI Courchevel Limited | Administrative & support | 2007 |
| Skill Issues Ltd | Arts & recreation | 2023 |
| Skill Scaffolding Plymouth Ltd | Construction | 2021 |
| Skilled Barber Limited | Other services | 2023 |
| Skills to Group Limited | Education | 1993 |
| Skillzmd.Com Ltd | Manufacturing | 2026 |
| Skin and Essence Ltd | Health & social care | 2024 |
| Skin Decisions Limited | Real estate | 2022 |
| Skin Deep Hair Limited | Other services | 2016 |
| Skin Excellence Clinics Ltd | Health & social care | 2017 |
| Skin Southwest Ltd | Health & social care | 2017 |
| Skin TAG Clinic Ltd | Health & social care | 2026 |
| SKK Services Limited | Health & social care | 2017 |
| Skof Limited | Wholesale & retail | 2018 |
| SKP Fitness Limited | Arts & recreation | 2025 |
| SKP Logistics Limited | Transport & logistics | 2024 |
| Skriptiksales Ltd | Wholesale & retail | 2026 |
| Sky Space Team Development CIC | Professional & scientific | 2020 |
| Skyblue Cabin Interiors Ltd | Manufacturing | 2018 |
| Skye High Commerce Ltd | Wholesale & retail | 2026 |
| Skye's RAW Food Pantry Ltd | Wholesale & retail | 2018 |
| Skylark (South) Ltd | Health & social care | 2021 |
| Skylark Holdings (SW) Limited | Financial services | 2022 |
| Skyline IT Solutions Ltd | Wholesale & retail | 2025 |
| Skyline Kebab Ltd | Hospitality | 2023 |
| Skyline Roofing (SW) Limited | Construction | 2026 |
| Skyline Scaffolding Limited | Construction | 2023 |
| Skyline Scaffolding Solutions Limited | Construction | 2025 |
| Skyrotec Limited | Construction | 2026 |
| Skyscape Global Ltd | Wholesale & retail | 2019 |
| Skyway Accounting Ltd | Professional & scientific | 2024 |
| Slack Communications Ltd | Professional & scientific | 2013 |
| Slaters Investment Property Ltd | Real estate | 2025 |
| SLC Marine Services Limited | Transport & logistics | 2015 |
| SLC Plumbing & Maintenance Limited | Construction | 2026 |
| Sleep & Hill Motors Limited | Wholesale & retail | 2011 |
| SLH Ventures Limited | Wholesale & retail | 1984 |
| Slice of Heaven Limited | Hospitality | 2023 |
| Slipinski Properties Ltd | Real estate | 2021 |
| SLJ Estates Property Ltd | Real estate | 2025 |
| SLJ Helicopter Services Ltd | Professional & scientific | 2023 |
| Slojak Realty Group (SRG) Limited | Real estate | 2026 |
| Slrfm Limited | Water & waste | 2017 |
| SLS Freight Forwarders Private Limited | Transport & logistics | 2026 |
| SM & WW Limited | Manufacturing | 2025 |
| SM Group (Europe) Ltd. | Wholesale & retail | 1977 |
| Smahajcsik Production Ltd | Manufacturing | 2019 |
| Smallridge Group Ltd | Water & waste | 2024 |
| Smart Applications Management Limited | Other services | 2016 |
| Smart Cookie Virtual Assistant Limited | Administrative & support | 2024 |
| Smart for Business Ltd | Professional & scientific | 2024 |
| Smart Gadget Station Ltd | Wholesale & retail | 2018 |
| Smart Money Financial Limited | Financial services | 2010 |
| Smart Sound Plymouth Ltd | Professional & scientific | 2000 |
| Smart Style Limited | Construction | 2022 |
| Smart Wash Services Ltd | Administrative & support | 2023 |
| Smart Wash Solutions Limited | Other services | 2012 |
| Smart Welcomes Limited | Administrative & support | 2024 |
| Smartlord Ltd | Real estate | 2018 |
| Smashland Burgers Ltd | Hospitality | 2023 |
| Smaxsman Enterprises Ltd | Transport & logistics | 2025 |
| SMB Sweeper Hire Ltd | Construction | 2024 |
| SMC Freeholdings Limited | Households | 2010 |
| SME Innovations Ltd | Information & communication | 2024 |
| Smeaton Block Ltd | Real estate | 2020 |
| Smeaton Healthcare Limited | Administrative & support | 2019 |
| Smeaton Holdings Ltd | Professional & scientific | 2024 |
| Smeaton Homes Holdings Ltd | Extraterritorial | 2014 |
| Smeaton Homes Limited | Real estate | 2008 |
| Smeaton Maintenance Ltd | Other services | 2020 |
| Smeaton Sales Ltd | Real estate | 2014 |
| Smeaton Students Ltd | Real estate | 2018 |
| Smeatons Access Limited | Construction | 2023 |
| Smile Care Cosmetic Centre Ltd | Health & social care | 2011 |
| Smile Studio by Arefa Ltd | Health & social care | 2026 |
| Smilesforlife Limited | Other services | 2022 |
| Smith & Best Ltd | Real estate | 2022 |
| Smiths Hosting Ltd | Information & communication | 2025 |
| Smiths Scents Ltd | Wholesale & retail | 2025 |
| Smiths Signature Scents Ltd | Wholesale & retail | 2025 |
| SML Plymouth Limited | Hospitality | 2020 |
| SML Property Solutions Limited | Construction | 2009 |
| Smllj Limited | Financial services | 2023 |
| SMO Surgery Ltd | Health & social care | 2025 |
| Smokey Joe's Kiosk Limited | Wholesale & retail | 2019 |
| Smokey Jo’S @ NO 6 Ltd | Hospitality | 2026 |
| Smoking Fish Limited | Professional & scientific | 2024 |
| SMP Music Ltd | Information & communication | 2021 |
| SMR Properties (SW) Limited | Real estate | 2023 |