| Sizzler Twist Limited | Arts & recreation | 2014 |
| SJ Aerospace Ltd | Manufacturing | 2018 |
| SJ Vehicleng Limited | Manufacturing | 2018 |
| SJ Waves Limited | Arts & recreation | 2023 |
| SJM Infotech Limited | Transport & logistics | 2007 |
| SJR Aerospace Ltd | Construction | 2019 |
| Skarla Retail Limited | Wholesale & retail | 2014 |
| Skate Display Company Ltd | Wholesale & retail | 2018 |
| Skills for the Jungle Limited | Administrative & support | 2015 |
| Skinsart Limited | Arts & recreation | 2020 |
| Skomer Close (10A & 10B) Limited | Real estate | 2023 |
| Smat Engineering Limited | Manufacturing | 2018 |
| Sopuw Limited | Construction | 2022 |
| South View Engineering Limited | Manufacturing | 2016 |
| South Wales Catering Trailers Ltd | Hospitality | 2026 |
| South Wales Hygiene Limited | Administrative & support | 2019 |
| South Wales Stays Ltd | Real estate | 2020 |
| Southcove Recordings Ltd | Information & communication | 2020 |
| SP Assist Limited | Administrative & support | 2014 |
| Speed 7000 Limited | Financial services | 2007 |
| Spetrov Ltd | Transport & logistics | 2016 |
| Spinesfirst Limited | Health & social care | 2019 |
| SRM Composites Limited | Manufacturing | 2015 |
| SRS A/C ENG Solutions Limited | Manufacturing | 2021 |
| Star Rays Limited | Hospitality | 2018 |
| Star Training Solutions Ltd | Professional & scientific | 2005 |
| Stellar Collection Ltd | Other services | 2025 |
| Stephen Knipe (Wales) Limited | Financial services | 2003 |
| Steve Lane Limited | Transport & logistics | 2001 |
| Still in the Fight Ltd | Wholesale & retail | 2025 |
| Stoke Shack Ltd | Real estate | 2025 |
| Street Wise Accountancy Limited | Professional & scientific | 1996 |
| Streetwise Solutions Limited | Professional & scientific | 1998 |
| Structural Composites Limited | Manufacturing | 2017 |
| STU Davies Interiors Limited | Manufacturing | 2023 |
| Sturniolo Associates Limited | Professional & scientific | 2025 |
| Subexotic Records LLP | | 2010 |
| Sublime Homes Limited | Construction | 2004 |
| Superordinary Ltd | Professional & scientific | 2025 |
| Surfers Lodge Ltd | Hospitality | 2024 |
| Sussed Wales | Wholesale & retail | 2005 |
| Swac Engineering Ltd | Manufacturing | 2018 |
| Swansea Asbestos Services Limited | Professional & scientific | 2017 |
| Swansea Bay Limited | Professional & scientific | 2015 |
| Sweet PEA Photography Ltd | Professional & scientific | 2017 |
| SWM Developments Ltd | Construction | 1996 |
| T Hurt Fabrications Ltd | Manufacturing | 2023 |
| T I Evans Consultancy Limited | Professional & scientific | 2016 |
| T Protheroe Electrical Contracting Limited | Construction | 2009 |
| T.E.A.M Design and Automation Limited | Manufacturing | 2021 |
| Take ME Porthcawl Limited | Transport & logistics | 2023 |
| Tams Welding Limited | Construction | 2013 |
| Tasc Aeronautical Limited | Transport & logistics | 2010 |
| Taylor and Lecraw Ltd | Real estate | 2022 |
| Tckc Limited | Administrative & support | 2021 |
| Teamwork Technology Services Limited | Information & communication | 2003 |
| Tech Ready Limited | Wholesale & retail | 2016 |
| Tech-Lub. (UK) Limited | Real estate | 1993 |
| Technosolve Limited | Information & communication | 1998 |
| Terwil Limited | Professional & scientific | 2021 |
| TG Hospitality Services Limited | Real estate | 2020 |
| TGT Specialist Coatings Limited | Manufacturing | 2018 |
| THE Aesthetic Clinic and Academy Ltd | Other services | 2019 |
| THE Ancient Briton (Newton) Ltd | Hospitality | 2023 |
| THE Beaton Group Ltd | Hospitality | 2025 |
| THE Bone Cartel Ltd | Hospitality | 2024 |
| THE Burrows Day Care Nursery (Porthcawl) Limited | Health & social care | 2010 |
| THE Collagen Clinic Limited | Other services | 2020 |
| THE Dancing Turtle Ltd | Hospitality | 2023 |
| THE Fireplace Cente Porthcawl Ltd | Wholesale & retail | 2018 |
| THE Fishmonger's Cat Ltd | Wholesale & retail | 2016 |
| THE Flooring Cube Ltd | Construction | 2018 |
| THE Fruit Bowl (Porthcawl) Limited | Wholesale & retail | 2021 |
| THE Globe Inn Hotel Ltd | Hospitality | 2019 |
| THE Glow Within Clinic Limited | Other services | 2024 |
| THE Honeycomb Hideaways Ltd | Financial services | 2005 |
| THE Hospitality Academy Limited | Education | 2015 |
| THE Junior ISA Ltd | Financial services | 2011 |
| THE Laundry Co (SW) Limited | Other services | 2026 |
| THE Little Black Box 23 Ltd | Hospitality | 2023 |
| THE Little Doodle Co Ltd | Wholesale & retail | 2025 |
| THE Little Laser Co Ltd | Other services | 2021 |
| THE Pantri Box Community Interest Company | Wholesale & retail | 2019 |
| THE Paperwork People Limited | Professional & scientific | 2015 |
| THE Place to Stay in Wales Ltd | Hospitality | 2022 |
| THE Posh Door Company Limited | Wholesale & retail | 2019 |
| Therapy and Assessment Service Ltd | Health & social care | 2016 |
| Thomas Automotive Solutions Limited | Wholesale & retail | 2015 |
| TITAN8 Security Ltd | Administrative & support | 2026 |
| TJ Rated Services Ltd | Administrative & support | 2023 |
| TLB Vale Ltd | Financial services | 2025 |
| TLI Hospitality Limited | Hospitality | 2025 |
| TM Property and Holdings Limited | Real estate | 2024 |
| TNB Developments Limited | Manufacturing | 2016 |
| TOF Property Limited | Hospitality | 2021 |
| TOM Mcnulty Design Limited | Manufacturing | 2014 |
| Tony M Rees Bulk Haulage Limited | Transport & logistics | 2010 |
| Top Slot (Shopfitting Systems) Limited | Manufacturing | 1989 |
| Trawlers & Haulers Porthcawl Ltd | Agriculture & fishing | 2024 |
| Tremain's Physiotherapy and Rehabilitation Services Limited | Health & social care | 2014 |