| 1000WORDS Limited | Professional & scientific | 2025 |
| A Breath of Fresh Air Gwynedd Ltd | Health & social care | 2021 |
| A Cloud 9 Ltd | Wholesale & retail | 2025 |
| A E Motors Ltd | Wholesale & retail | 2013 |
| A. J Brown Electrical Contracting Ltd | Construction | 2013 |
| Abbey Farm Caravan Parks Limited | Hospitality | 2014 |
| ABC Does Ltd | Education | 2010 |
| Aberdaron Farm Holidays Limited | Hospitality | 2012 |
| Allport Metal Recycling Limited | Water & waste | 2005 |
| Alton Murphy & Leanne Murphy Optometrists Limited | Administrative & support | 1996 |
| Alun Pierce CYF | Transport & logistics | 2018 |
| AN Reeves & Roberts & Owen Limited | Wholesale & retail | 2014 |
| Ananta Retails Limited | Wholesale & retail | 2015 |
| Andy Barker Ltd | Professional & scientific | 2013 |
| Anglesey Boat Solutions Limited | Professional & scientific | 2016 |
| Apple Cube Ltd | Hospitality | 2021 |
| Arlwyo Golff Porthmadog CYF | Hospitality | 2019 |
| Aroma Ochirly Limited | Hospitality | 2024 |
| Arthora CYF | Administrative & support | 2025 |
| Artro Property Services Ltd | Construction | 2012 |
| Aspects of Snowdonia Limited | Manufacturing | 2012 |
| Aspire EOT Limited | Financial services | 2022 |
| Aspire Park and Leisure Homes Ltd | Manufacturing | 2014 |
| Astp Trading Limited | Administrative & support | 2017 |
| Atls Solutions Limited | Professional & scientific | 2022 |
| AWJ Offshore & Diving Services Ltd | Professional & scientific | 2014 |
| B & a Jones Ltd | Agriculture & fishing | 2013 |
| B & M Taxis Limited | Transport & logistics | 2016 |
| B & S Siting Limited | Construction | 2012 |
| Baavet CYF | Wholesale & retail | 2009 |
| Babipur Ltd | Wholesale & retail | 2012 |
| Ballistol OIL Ltd | Wholesale & retail | 2019 |
| Bangor Glass & Glazing Limited | Professional & scientific | 1986 |
| Beespeed Ltd | Wholesale & retail | 2017 |
| Benar CYF | Financial services | 2014 |
| Benar DAU CYF | Households | 2018 |
| Berwyn Parry (Adeiladwyr) CYF | Construction | 2003 |
| Bethan Roberts CYF | Hospitality | 2015 |
| Blockwise Services Ltd | Professional & scientific | 2025 |
| Bodwrog Limited | Hospitality | 2015 |
| Boltholes & Hideaways Limited | Hospitality | 2013 |
| Bootons Hospitality Ltd | Hospitality | 2024 |
| Border Training Services Limited | Hospitality | 2002 |
| Box Bermo Storage Ltd | Transport & logistics | 2024 |
| Brady Scaffolding CYF | Construction | 2004 |
| Brian Bown CYF | Administrative & support | 2012 |
| Bricsan CYF | Construction | 2026 |
| Brief Coaching Ltd | Education | 2006 |
| Bryn Derw Country Sports Ltd | Information & communication | 2018 |
| Bryn Melyn CYF | Administrative & support | 2019 |
| Bryn Parciau CYF | Households | 2023 |
| Brython Tecwyn CYF | Manufacturing | 2011 |
| C.D.L. Fire Protection Ltd | Construction | 2018 |
| C.P.D. Porthmadog F.C. Ltd. | Arts & recreation | 1993 |
| Cader Fish and Chips Ltd | Hospitality | 2021 |
| Cadno CYF | Hospitality | 2026 |
| CAE Clyd CYF | Hospitality | 2016 |
| Caffi Colwyn Limited | Hospitality | 2014 |
| Caffi Gwynant CYF | Hospitality | 2016 |
| Caffi Porthor CYF | Hospitality | 2019 |
| CAI Roberts CYF | Agriculture & fishing | 2013 |
| Cakiroglu FIN Limited | Households | 2022 |
| Calavon Ltd | Wholesale & retail | 2025 |
| Calonau CYF | Hospitality | 2025 |
| Calvin Stewart DA Ltd | Transport & logistics | 2025 |
| Cambrian Electrical (Gwynedd) Ltd | Construction | 2019 |
| Cambrian Fire Risk Assessments Ltd | Financial services | 2025 |
| Camping in Llanberis Limited | Hospitality | 2018 |
| Cariad Care Homes Ltd | Health & social care | 1998 |
| Cariad Gelato Limited | Manufacturing | 2021 |
| Cariad Group Holdings Ltd | Financial services | 2023 |
| Carrog Roberts CYF | Agriculture & fishing | 2022 |
| Cartra' Clyd CYF | Wholesale & retail | 2023 |
| Cartrefi Cyfoes Cyfyngedig | Construction | 2019 |
| Cartrefi Gerddi Madryn CYF | Construction | 2020 |
| Cartrefi Roberts LLP | | 2024 |
| Cartrefi'R Hafod CYF | Real estate | 2017 |
| Carwyn AP Plymio a Gwresogi CYF | Construction | 2025 |
| Cath CYF | Health & social care | 2008 |
| Cerdd DW Music CYF | Education | 2018 |
| Ceri Elisabeth Legal Ltd | Professional & scientific | 2023 |
| CFW Holdings Limited | Administrative & support | 2016 |
| Chester Place Limited | Real estate | 2014 |
| Chiara Limited | Manufacturing | 1999 |
| Chris Jones Building and Resin Ltd | Construction | 2021 |
| Chris Waite Site Engineering Ltd | Construction | 2014 |
| Church Bay Investments (Anglesey) Ltd | Real estate | 2025 |
| Cigydd Glaslyn Butchers Ltd | Wholesale & retail | 2026 |
| Clifton Glass Limited | Construction | 2006 |
| Cliptt Ltd | Manufacturing | 2025 |
| Clive Evans Limited | Construction | 2003 |
| Cloarian CYF | Hospitality | 2025 |
| Clwb Pel-Droed Llanystumdwy CYF | Arts & recreation | 2016 |
| Coffee Club Ltd | Wholesale & retail | 2013 |
| Coffi Ltd | Wholesale & retail | 2012 |
| Colin Jones (Rock Engineering) Limited | Construction | 1997 |
| Contouring Cosmetics Limited | Administrative & support | 1999 |
| Contractio G I Owen Contracting CYF | Construction | 2020 |
| Cornhill Environmental Solutions Ltd | Water & waste | 2005 |
| Corporate Technologies Ltd | Professional & scientific | 1994 |