| Peeble'Shire Windows Doors Conservatories Limited | Administrative & support | 2000 |
| Penllyn Caravan Park Limited | Hospitality | 1997 |
| Pennog Limited | Professional & scientific | 2012 |
| Penrhyn Hire Limited | Administrative & support | 1987 |
| Pentraeth Automotive Limited | Wholesale & retail | 1994 |
| Phil Hughes Limited | Construction | 2007 |
| Phoenix Metals & Demolition Limited | Wholesale & retail | 2006 |
| Port Penrhyn (Plant) Limited | Transport & logistics | 1977 |
| Povey Butchers Limited | Manufacturing | 2006 |
| Povey's Garage Ltd | Wholesale & retail | 1978 |
| PPM Technology Limited | Manufacturing | 1999 |
| Product Launch Limited | | 1980 |
| Pulrose Motor Services Limited | Wholesale & retail | 1962 |
| Purbani Frozen Food Ltd. | Extraterritorial | 1999 |
| Pwllheli Food Limited | Hospitality | 2025 |
| Pwllheli Marine Centre Limited | Real estate | 1997 |
| Pwllheli Masonic Hall,Limited(The) | Other services | 1929 |
| R O Williams & Sons Limited | Construction | 2007 |
| R.A. & W. Jones Autocare Limited | Wholesale & retail | 2003 |
| R.G. Owen Limited | Construction | 2002 |
| Rafi Limited | Hospitality | 2015 |
| Rheilffordd Llyn Tegid Limited | Transport & logistics | 1972 |
| Rivertime Entertainment Limited | Information & communication | 2006 |
| Robert Midwood Limited | Construction | 2005 |
| Roberts & Sons Caravan Services Limited | Other services | 2006 |
| Roden & SON Limited | Construction | 2006 |
| Rowena Lawn and Forest Machinery Ltd | Real estate | 1979 |
| S a Jones Ltd | Construction | 2007 |
| S.J. & S. Williams Limited | Construction | 2003 |
| Sangaw Store Ltd | Wholesale & retail | 2024 |
| Sbensh Systems Solutions Limited | Professional & scientific | 2023 |
| Sea View Management Number 1 Limited | Households | 1998 |
| Sea View Management Number 2 Limited | Households | 1998 |
| Seren Ffestiniog CYF. | Public administration | 1998 |
| Shell Island Limited | Hospitality | 2011 |
| Shoker Enterprises Ltd | Wholesale & retail | 2006 |
| Shoker Trading Limited | Wholesale & retail | 2006 |
| Shop DRE Ltd | Wholesale & retail | 2025 |
| Sickle Holdings Limited | Financial services | 2005 |
| Signal Surveyors Limited | Professional & scientific | 2012 |
| Simplicitas. Limited | Health & social care | 2007 |
| Sisial Ltd | Wholesale & retail | 2013 |
| Slate Heritage International | Arts & recreation | 1996 |
| Slatedirect Limited | Extraterritorial | 2004 |
| Slatepath Ltd | Hospitality | 2025 |
| Snowdon Safety Solutions Ltd. | Professional & scientific | 2025 |
| Snowdonia Fire Protection Limited | Construction | 2003 |
| Snowdonia Peaks & Valleys Ltd | Other services | 2017 |
| Software Affair Limited | Information & communication | 2015 |
| Steil CYF | Wholesale & retail | 2002 |
| Stonewyrcs Cyfyngedig | Construction | 2007 |
| Sun&Eclipse UK Ltd | Wholesale & retail | 2026 |
| Swear Limited | Wholesale & retail | 2003 |
| Sylfaen Cymunedol CYF | Education | 2001 |
| Tafwys CYF | Arts & recreation | 1993 |
| THE Bespoke Traveller Ltd | Administrative & support | 2024 |
| THE C.Store Limited | Transport & logistics | 2006 |
| THE Harp Inn Limited | Hospitality | 2012 |
| THE Housekeeper Ltd | Administrative & support | 2017 |
| THE Old Deanery Limited | Health & social care | 2002 |
| Thompson Brothers (Anglesey) Ltd | Construction | 2003 |
| Time Domain Solutions Limited | Professional & scientific | 2003 |
| Tirwedd Dyffryn Aber CYF. | Professional & scientific | 2006 |
| Towyn Road Garage Limited | Manufacturing | 2007 |
| Trawstir CYF | Administrative & support | 2025 |
| TU Mewn Cyfyngedig | Manufacturing | 2005 |
| TY Bryn Limited | Health & social care | 2004 |
| TY MON Management Limited | Households | 2007 |
| Tyfu Eryri CYF | Agriculture & fishing | 2022 |
| Urban Coast Limited | Wholesale & retail | 2005 |
| Vera Bluebell Limited | Agriculture & fishing | 2007 |
| Waste Wales Limited | Water & waste | 2007 |
| Watkin Property Ventures Investments NO3 Limited | Real estate | 2024 |
| Welsh Highland Railway Construction Limited | Construction | 2004 |
| Welsh Lady Preserves | Manufacturing | 1978 |
| Wern Building Development Limited | Construction | 2005 |
| West END Grading Cymru Limited | Wholesale & retail | 2015 |
| William Partington Marine Limited | Manufacturing | 1958 |
| Williams & Jones Lawn & Landscaping Limited | Administrative & support | 2025 |
| Williams a Williams CYF | Water & waste | 2003 |
| Y Noddfa Cyfyngedig | Professional & scientific | 2006 |
| Y Wylan CYF | Hospitality | 2003 |