| Prestige Motors (UK) Limited | Wholesale & retail | 1999 |
| Price Bros,& Company(Penarth)Limited | Water & waste | 1923 |
| Publicity Centre Limited | Administrative & support | 1984 |
| PWS (Wales) Limited | Wholesale & retail | 2006 |
| R & D Fencing Limited | Administrative & support | 2003 |
| R G Legal Ltd | Professional & scientific | 2007 |
| R.V.Elliott & Co.Limited | Construction | 1972 |
| Rebuiltx Limited | Information & communication | 2025 |
| Reliance-Barker-Davies Limited | Manufacturing | 1987 |
| RTB Homes Limited | Construction | 2004 |
| S T Kelly Construction Limited | Construction | 2002 |
| Sanleb Limited | Hospitality | 2023 |
| Setup Displays Cardiff Limited | Administrative & support | 1999 |
| Smile Studio Penarth Ltd | Health & social care | 2003 |
| Smileygas Consultancy Ltd | Information & communication | 2002 |
| Smiths Transport Services Limited | Manufacturing | 1999 |
| SMJ Construction Limited | Construction | 2000 |
| South Wales Developments Limited | | 1986 |
| Southgate Restaurants Limited | Real estate | 1963 |
| Sully Budokan Limited | Arts & recreation | 2006 |
| Swanbridge Beach Limited | Real estate | 2003 |
| T.G.M.Gauge Maintenance Limited | Extraterritorial | 1971 |
| Techniquest | Education | 1985 |
| THE Appointment Factory Limited | Administrative & support | 2003 |
| THE Fabric Mill Limited | Wholesale & retail | 2003 |
| THE Genesis Media Group Limited | Information & communication | 1999 |
| THE Office Development Ltd | Extraterritorial | 2025 |
| THE Print Centre Limited | Manufacturing | 1999 |
| Trustmark Limited | Manufacturing | 1974 |
| TY Draw & Wentworth Lodge Limited | Health & social care | 2002 |
| Victoria Park Cars Limited | Professional & scientific | 2006 |
| Victoria Park Motor Co. Limited | Wholesale & retail | 1982 |
| Vintage '83 Limited | Wholesale & retail | 1995 |
| W.G. Davies (Tobacconist Cowbridge) Limited | Wholesale & retail | 1966 |
| W.J.B. Pension Fund Trustees Limited | Financial services | 1984 |
| Wandex Builders Limited | Construction | 1975 |
| Waverley Court Consulting Ltd | Financial services | 2006 |
| Windymarsh Limited | Transport & logistics | 1999 |
| Woodside Court Limited | Households | 1982 |