| C R Gilbert Limited | Construction | 2003 |
| C S S Property Investments Ltd | Real estate | 2023 |
| C S Simpson & Associates Limited | Wholesale & retail | 2017 |
| C-Tech Marine LLP | | 2025 |
| CAE Construction Limited | Construction | 2003 |
| Cafe Artemis Limited | Hospitality | 2026 |
| Caffi Colwyn Coffee & Sandwich Bar Limited | Hospitality | 2019 |
| Cais Social Enterprises Ltd. | Administrative & support | 2007 |
| Cambria Caravan Park Limited | Hospitality | 2003 |
| Cambria Developments Limited | Construction | 2007 |
| Cambria Homes Limited | Construction | 1994 |
| Cambrian Photography Limited | Professional & scientific | 2003 |
| Campbell Grindlay Engineering Limited | Manufacturing | 2005 |
| Caravan & Leisure Insurance Consultants Limited | Financial services | 2003 |
| Carbon Culture (NW) Ltd | Wholesale & retail | 2023 |
| Cariad Collectables Limited | Extraterritorial | 2011 |
| Carl Higham Financial Planning Ltd | Financial services | 2016 |
| Carlo's Limited | Hospitality | 2007 |
| Carmel Music Publishing Ltd | Information & communication | 2023 |
| Castle Quay Mews Limited | Households | 2002 |
| Cat Jane Fitness Ltd | Other services | 2022 |
| Cayley One Ltd | Hospitality | 2025 |
| CEN AP Tomos Cyfyngedig | Wholesale & retail | 2006 |
| Centacare Ltd | Health & social care | 2025 |
| Centre of Sign-Sight-Sound Y Ganolfan Arwyddo-Golwg-Sain | Health & social care | 1994 |
| CES Franchise Ltd | Wholesale & retail | 2024 |
| CFM Enterprises Ltd | Hospitality | 2013 |
| CGT Investments Limited | Professional & scientific | 2012 |
| CH Commercial Finance Ltd | Financial services | 2025 |
| CH Mortgages NW Ltd | Financial services | 2023 |
| Chaat Colwyn Bay Ltd | Hospitality | 2024 |
| Chairs@Thehairshop Ltd | Other services | 2023 |
| Chalarmar Properties Ltd | Construction | 2026 |
| Change With Emily Ltd | Professional & scientific | 2014 |
| Chaseley House Residential Home Limited | Health & social care | 2003 |
| Chc-Construction Ltd | Other services | 2018 |
| Chemehs Limited | Professional & scientific | 2023 |
| Cheng XIN Limited | Hospitality | 2019 |
| Chester Padel Club Limited | Arts & recreation | 2025 |
| Church Close Colwyn Bay Management Company Limited | Real estate | 2025 |
| Cinnaman Ltd | Real estate | 2014 |
| Cinos Beauty Ltd | Other services | 2026 |
| Civils South East Limited | Administrative & support | 2016 |
| CJR Trading (UK) Limited | Wholesale & retail | 2011 |
| Clecs Media CYF | Information & communication | 2022 |
| Climbers Market Ltd | Wholesale & retail | 2023 |
| Climbwales Ltd | Education | 2022 |
| CMR Contractors Ltd | Construction | 2021 |
| Cnprojects Ltd | Real estate | 2025 |
| Coast Community Radio and Media CIC | Information & communication | 2018 |
| Coastal Building & Renovation Ltd | Construction | 2025 |
| Coastal Ceramics Limited | Wholesale & retail | 2005 |
| Coastal Medical Imaging Ltd | Health & social care | 2021 |
| Coastal Rendering Specialists Ltd | Construction | 2020 |
| Cogitoergovici Limited | Administrative & support | 2023 |
| Cognitive-Edge Ltd | Information & communication | 2014 |
| Colesbourne Consulting Ltd | Professional & scientific | 2017 |
| Cols Travels Ltd | Information & communication | 2026 |
| Colsol Wales Limited | Education | 2016 |
| Colwyn Bay Catering Ltd | Hospitality | 2024 |
| Colwyn Bay Community HWB CIC | Arts & recreation | 2024 |
| Colwyn Bay Industrial Doors Limited | Construction | 2012 |
| Colwyn Bay Kebab House Limited | Hospitality | 2023 |
| Colwyn Bay Rugby Football Club Limited | Arts & recreation | 2016 |
| Colwyn Fireplace Centre Limited | Construction | 2003 |
| Colwyn Interiors Home Improvements Ltd | Construction | 2017 |
| Colwyn Spice HUT Limited | Hospitality | 2017 |
| Commando X Fit Wellbeing CIC | Arts & recreation | 2021 |
| Commercial Funding (75POINT3) LLP | | 2022 |
| Community & Voluntary Support Conwy | Other services | 1999 |
| Compassionate Community Care Conwy Ltd | Health & social care | 2026 |
| Complete Education Solutions Limited | Information & communication | 2017 |
| Computer World Solutions Limited | Wholesale & retail | 2004 |
| Connected Business English Limited | Education | 2022 |
| Connected Management Limited | Professional & scientific | 2005 |
| Conroy Logistics Ltd | Transport & logistics | 2026 |
| Conwy Asset Management Limited | Financial services | 2024 |
| Conwy Brokerage Limited | Wholesale & retail | 2024 |
| Conwy Caravans Limited | Wholesale & retail | 2024 |
| Conwy Cleaning Solutions Limited | Administrative & support | 2026 |
| Conwy Collision Centre Ltd | Wholesale & retail | 2025 |
| Conwy Community Riding Centre CIC | Agriculture & fishing | 2021 |
| Conwy Drainage Solutions Ltd | Construction | 2025 |
| Conwy Fire Protection Ltd | Public administration | 2026 |
| Conwy Garth Management Company Limited | Households | 1980 |
| Conwy Hire Limited | Administrative & support | 2024 |
| Conwy Home and Garden Ltd | Construction | 2024 |
| Conwy Motorsport Engineering Limited | Manufacturing | 2019 |
| Conwy Pest Solutions Limited | Administrative & support | 2021 |
| Conwy Pirates CIC | Arts & recreation | 2024 |
| Conwy Property & Joinery Services Ltd | Construction | 2022 |
| Conwy Terrace Management Limited | Households | 2005 |
| Conwy Trailers Ltd | Wholesale & retail | 2025 |
| Conwy Window Cleaning Services Limited | Administrative & support | 2026 |
| Cooper Belli Limited | Wholesale & retail | 2016 |
| Cooper Newman Property Limited | Real estate | 2013 |
| Corvus Device Limited | Other services | 2015 |
| Cosmic Productions Ltd | Wholesale & retail | 2025 |
| Country and Coast Retreats Ltd | Real estate | 2026 |
| CPB Trainings Limited | Real estate | 2010 |