| ECS123 Limited | Construction | 2019 |
| Egni CYF | Professional & scientific | 1998 |
| Eich Eiddo CYF. | Professional & scientific | 2025 |
| Eiddo Iola Jones Properties CYF | Real estate | 2024 |
| Eiddo Lloyd's Property Ltd | Real estate | 2024 |
| Eiddo QS Ltd | Real estate | 2024 |
| Eiddo Susan Jones Properties CYF | Real estate | 2021 |
| Eisffora Cyfyngedig | Administrative & support | 2009 |
| Elano Developments CYF | Real estate | 2026 |
| Eleger CYF | Real estate | 2006 |
| Elis Williams Construction Limited | Construction | 2007 |
| Empowered Wellness Limited | Other services | 2025 |
| Emyr Gwyn Williams and SON (Delfryn) Limited | Wholesale & retail | 2015 |
| Enfys Consulting Limited | Professional & scientific | 2019 |
| Engedi Consulting Ltd | Professional & scientific | 2025 |
| EPC Home Energy Ltd | Professional & scientific | 2025 |
| Euphoria Beauty Limited | Arts & recreation | 2026 |
| Evan Evans Electrical Ltd | Construction | 2007 |
| Ewee Holdings Limited | Financial services | 2018 |
| Ewee Properties Limited | Real estate | 2018 |
| Farm Spa Holidays Limited | Hospitality | 2007 |
| Fferm Plas Gwyn Limited | Hospitality | 2023 |
| Fferm Ty'N Rhos Penarth CYF | Agriculture & fishing | 2025 |
| Fferyllwyr Llyn CYF | Wholesale & retail | 2003 |
| Flippin Fabulous Furniture Ltd | Wholesale & retail | 2024 |
| Four Points Services Limited | Hospitality | 2023 |
| FS Sportfishing Club Ltd | Arts & recreation | 2021 |
| G H J Civil Engineering Limited | Construction | 2005 |
| G Jones Heating & Plumbing Ltd | Construction | 2007 |
| G L Jones (Builders) Limited | Construction | 2005 |
| G T Williams Holdings Ltd | Financial services | 2024 |
| G&S Financial Solutions LLP | | 2019 |
| G. & M. Roberts Fishing (Nefyn) Limited | Agriculture & fishing | 2003 |
| G. D. Roberts & SON CYF | Other services | 2019 |
| G.Williams Ffensio CYF | Agriculture & fishing | 2023 |
| Garth Pwllheli CYF | Real estate | 2023 |
| Gary Rose Properties Limited | Real estate | 2017 |
| GAS Direct Cymru Cyfyngedig | Administrative & support | 2005 |
| GEE Rental Ltd | Real estate | 2025 |
| Gelliwig Farm Caravan Park Limited | Hospitality | 2022 |
| Genius (Pwll) Ltd | Wholesale & retail | 2021 |
| Genius (Pwllheli) Limited | Wholesale & retail | 2017 |
| Glampio Fychan CYF | Hospitality | 2023 |
| Glasfryn Activity Park Ltd | Arts & recreation | 2024 |
| Glyn Garth Club | Hospitality | 2011 |
| Glân Gwynus CYF | Administrative & support | 2023 |
| Gofod 53 CYF | Hospitality | 2026 |
| Golau TM Ltd | Administrative & support | 2025 |
| Golli Marketing Ltd | Professional & scientific | 2024 |
| Good Company London Limited | Other services | 2025 |
| Goriad AUR CYF | Construction | 2016 |
| Gorwelion CYF | Professional & scientific | 2021 |
| Graham Hughes Services Limited | Construction | 2023 |
| Great Jobs UK Limited | Education | 2019 |
| Greenearth Hydro Limited | Manufacturing | 2010 |
| Griffith & Daughters Limited | Hospitality | 2021 |
| Griffith A'I Gwmni Cyfyngedig | Wholesale & retail | 2004 |
| Griffith Project Management Limited | Professional & scientific | 2017 |
| Griffith Real Estate Ltd | Real estate | 2020 |
| Gudger Holdings Limited | Financial services | 2014 |
| Gudger Investments Limited | Financial services | 2014 |
| Gwasanaeth Cychod Castellmarch CYF | Transport & logistics | 2011 |
| Gwasg Gwynedd Limited | Information & communication | 1973 |
| Gweithdy Kampala Workshop Cyfyngedig | Construction | 2009 |
| Gweithdy Llyn CYF | Construction | 2022 |
| Gwenllian Williams Ltd | Administrative & support | 2025 |
| Gwernabwy CYF | Construction | 2024 |
| Gwresogi Ltd | Construction | 2023 |
| Gwrtaith Gwynedd CYF | Water & waste | 2017 |
| Gwyliau Rhydolion Holidays Limited | Hospitality | 2010 |
| Gwyn Thomas and Co Limited | Professional & scientific | 2012 |
| Gwynedd Building Supplies Limited | Real estate | 1989 |
| Gwynedd Disposables CYF | Financial services | 2021 |
| Gwynedd Farm Machinery Limited | Wholesale & retail | 1997 |
| Gwynedd Windscreens Limited | Wholesale & retail | 2004 |
| Gwynfryn Cymunedol CYF. | Information & communication | 2000 |
| H & E Contractors Ltd | Construction | 2024 |
| H E Jones (Builders) Limited | Construction | 2005 |
| Hafan Gelli CYF | Hospitality | 2023 |
| Hafod Ceiri | Arts & recreation | 2015 |
| Hafren Environmental Associates Limited | Professional & scientific | 2019 |
| HAKA7 Ltd | Hospitality | 2019 |
| Hamdden Llyn CYF | Hospitality | 2003 |
| Harbour Marine Engineering Services Limited | Manufacturing | 2002 |
| Harbour Stoves (Installations) Ltd | Other services | 2021 |
| Harbour Stoves Limited | Wholesale & retail | 2019 |
| Harbwr CYF | Professional & scientific | 2023 |
| Harlech & District Motor Club Limited | Arts & recreation | 1988 |
| Harold Roberts & SON Limited | Administrative & support | 1982 |
| Harrison Shellfish Limited | Agriculture & fishing | 2003 |
| Haydn E. Williams Cyfyngedig | Professional & scientific | 2007 |
| Hayjo Holdings Ltd | Other services | 2024 |
| Hazelgrove Consultancy Limited | Professional & scientific | 2020 |
| HB Digital (Wales) Ltd | Information & communication | 2014 |
| Healthysleepmattress Ltd | Wholesale & retail | 2026 |
| Heath Mediation Limited | Professional & scientific | 2026 |
| Heavenly Gems Limited | Manufacturing | 2020 |
| Hell's Mouth Surf School Limited | Arts & recreation | 2010 |
| Hell’S Mouth Surf Co Ltd | Wholesale & retail | 2023 |
| Helsby Plas Crwth CYF | Hospitality | 2025 |