| Pro Outdoors Ltd | Wholesale & retail | 2025 |
| Property Concierge Group Ltd | Households | 2020 |
| Property Surveying & Maintenance Services Limited | Construction | 2020 |
| Prysglwyd Hydro Limited | Energy | 2016 |
| Puffin Park Ltd | Hospitality | 2017 |
| Pwllheli Dental Care Limited | Health & social care | 2010 |
| Pwllheli Development Co.Limited | Real estate | 1956 |
| Pwllheli Homecare Ltd | Health & social care | 2025 |
| Pwllheli Nails Ltd | Other services | 2024 |
| Pwllheli NO 1 HCW Ltd | Wholesale & retail | 2022 |
| Pysgod Hari-Haul CYF | Administrative & support | 2010 |
| Q W Construction Ltd | Construction | 2014 |
| QB Consulting Ltd | Professional & scientific | 2022 |
| Quick Wash Pwllheli Ltd | Administrative & support | 2025 |
| R & KW Limited | Agriculture & fishing | 2006 |
| R Charles Thomas Limited | Construction | 2005 |
| R E Jones Limited | Construction | 2013 |
| R E O Properties Ltd | Real estate | 2016 |
| R Hicks & Sons Limited | Extraterritorial | 1992 |
| R Hicks (Holdings) Limited | Real estate | 1990 |
| R S Ellis Limited | Administrative & support | 2015 |
| R.And A.Properties (North Wales) Limited | Extraterritorial | 2010 |
| R.D.Williams CYF | Financial services | 2007 |
| RAB Shields Financial Management Limited | Financial services | 2009 |
| Racked CYF | Information & communication | 2015 |
| Radical Academy Records Ltd | Information & communication | 2010 |
| Radix Shrewsbury Limited | Administrative & support | 2024 |
| Ralio Rownd CYF | Transport & logistics | 2018 |
| Ravzaan Ltd | Wholesale & retail | 2025 |
| Rebecca Clark Cyfyngedig | Real estate | 2016 |
| Red Garage Limited | Construction | 2008 |
| Refail CYF | Hospitality | 2019 |
| Refurb Electronics Limited | Wholesale & retail | 2024 |
| Rhos Y Foel CYF | Hospitality | 2019 |
| Rhosyr CYF | Real estate | 2022 |
| Richards Brothers Limited | Construction | 2010 |
| Ridge Marine Surveying Limited | Professional & scientific | 2014 |
| Rigio CYF | Wholesale & retail | 2017 |
| Riverside Gleamers Contracts Limited | Administrative & support | 2024 |
| Riverside Ranges Limited | Wholesale & retail | 2021 |
| Rjsc Family Limited | Extraterritorial | 2024 |
| RM Avionics Limited | Professional & scientific | 2025 |
| Roberts & Doyle Catering Ltd | Hospitality | 2008 |
| Roberts & Roberts Cleaning Services Ltd | Administrative & support | 2020 |
| Robyns Owen Law Limited | Professional & scientific | 2025 |
| Rodinia Green Energy Services Ltd | Professional & scientific | 2023 |
| Rooms@Martha Jones Ltd | Hospitality | 2018 |
| Rowlands Marine Electronics Limited | Manufacturing | 1982 |
| Rubie Nails 1 Ltd | Other services | 2025 |
| Rustic Bespoke Limited | Wholesale & retail | 2022 |
| Ryddid Limited | Manufacturing | 2009 |
| S E Metcalfe A'I Gwmni CYF | Construction | 2018 |
| Saevar Solutions Ltd | Administrative & support | 2026 |
| Salmac Properties Ltd | Real estate | 2018 |
| Sawna Criccieth Sauna Ltd | Health & social care | 2025 |
| Sbrigyn Ymborth CYF | Wholesale & retail | 2023 |
| Scarlett Angel Ltd | Extraterritorial | 2024 |
| Sea Breeze Pwllheli Limited | Households | 2016 |
| Sean Booth Landscapes Limited | Administrative & support | 2011 |
| Sean Devlin Catering Services Ltd | Hospitality | 2021 |
| Sela GAS Limited | Wholesale & retail | 2012 |
| Selar Ltd | Hospitality | 2025 |
| Seren Accountancy Services Ltd | Professional & scientific | 2020 |
| Seven Sparks Ltd | Administrative & support | 2026 |
| Ship Edern Ltd | Hospitality | 2018 |
| Sied Llaeth CYF | Wholesale & retail | 2021 |
| Signalx Limited | Transport & logistics | 2024 |
| Simpson Hargrave Limited | Other services | 2019 |
| Siop Fferm Abersoch CYF | Wholesale & retail | 2022 |
| Siop PEN Y Groes Llithfaen | Wholesale & retail | 2010 |
| Siptec UK Limited | Administrative & support | 2015 |
| Siscma Ltd | Wholesale & retail | 2014 |
| SJ Deliverys Ltd | Transport & logistics | 2025 |
| SJ. Leslie Limited | Hospitality | 2013 |
| Snowdonia Building Services Limited | Construction | 2017 |
| Snowdonia Ice Cream Company Ltd | Manufacturing | 2014 |
| Snowdonia Professional Tiling Ltd. | Construction | 2018 |
| Snowdrop Property Development (Gwynedd) Limited | Construction | 2023 |
| South Caernarvonshire Yacht Club Limited | Arts & recreation | 1984 |
| Sovereign Business Services Ltd | Financial services | 2020 |
| Sovereign Group (PEN Llyn) Ltd | Other services | 2019 |
| SP & GP Jones Limited | Construction | 2024 |
| ST Access Ltd | Construction | 2018 |
| Strain Parry LLP | | 2026 |
| Studio LWH Limited | Professional & scientific | 2025 |
| Sustainable Choice Ltd | Other services | 2016 |
| Swift Fire & Security Limited | Administrative & support | 2022 |
| T Barry Evans Property Services Ltd | Construction | 2019 |
| T W Williams & SON Ltd | Construction | 2014 |
| T Williams & SON Ltd | Real estate | 2002 |
| Tactical Adjustment Systems Limited | Manufacturing | 2008 |
| Tafarn Glyn Y Weddw Arms Cyfyngedig | Hospitality | 2009 |
| Tafarn YR Haul CYF | Hospitality | 2011 |
| TAI Ffolt Limited | Real estate | 2014 |
| TAI Llewelyn CYF | Hospitality | 2021 |
| Talafon Abersoch Limited | Wholesale & retail | 2020 |
| Talu Bils CYF | Administrative & support | 2020 |
| TAN Y Bryn Farm Caravan Site Limited | Hospitality | 2019 |
| Tanya Whitebits Ltd | Other services | 2012 |
| Tarian Y Coed CYF | Agriculture & fishing | 2026 |