| Central Game Sporting Limited | Agriculture & fishing | 2025 |
| Central Heating Designs Ltd. | Construction | 2001 |
| Central UK Limited | Professional & scientific | 2006 |
| Central Yarnton Bridge Club Ltd | Arts & recreation | 2019 |
| Centre for Political and Diplomatic Studies Limited | Education | 2011 |
| Certikin International Limited | Wholesale & retail | 1995 |
| Ceta Professional Services Limited | Information & communication | 2026 |
| Ceylona Ltd | Manufacturing | 2025 |
| CFS Training Ltd | Education | 2025 |
| CG Surface Design Ltd | Professional & scientific | 2024 |
| CGS Consultancy Limited | Professional & scientific | 2013 |
| Chadstone Services Limited | Professional & scientific | 2026 |
| Challow Design & Construction Limited | Extraterritorial | 1994 |
| Chameleon Works Limited | Professional & scientific | 2006 |
| Channel Books Limited | Manufacturing | 2013 |
| Chap Property Investments Ltd | Real estate | 2026 |
| Chapel LN Residents Limited | Households | 2023 |
| Chapel Studios Limited | Professional & scientific | 2002 |
| Chariot Farming Limited | Agriculture & fishing | 2016 |
| Charlbury and Overseas Community Projects Ltd | Health & social care | 2005 |
| Charlbury Beer Festival Limited | Hospitality | 2005 |
| Charles Edward Cordery Investments Ltd | Real estate | 2024 |
| Charles Eveson Consultancy Limited | Wholesale & retail | 2011 |
| Charles Prestige Limited | Wholesale & retail | 2022 |
| Charlett Building Services Limited | Construction | 2022 |
| Charlie Hamper Ltd | Wholesale & retail | 2022 |
| Charlie Hughes Limited | Construction | 2013 |
| Charlotte Hawkins Limited | Extraterritorial | 2024 |
| Charlotte Richardson Hawkins Ltd | Extraterritorial | 2024 |
| Charlotte Spurrier Ltd | Professional & scientific | 2022 |
| Charlottes Web (Dartmouth) Limited | Wholesale & retail | 2015 |
| Charter Film Productions Limited | Information & communication | 1973 |
| Chatfield Accountancy Limited | Professional & scientific | 2021 |
| Chaves Engineering Limited | Professional & scientific | 2011 |
| Chayter Holdings Limited | Professional & scientific | 2004 |
| Chef Select Ltd | Hospitality | 2017 |
| Cheltenham Comedy Festival Limited | Arts & recreation | 2011 |
| Chemicalsforswimmingpools Ltd | Construction | 2015 |
| Cherry Care Services Oxfordshire Ltd | Health & social care | 2013 |
| Cherry Trading Ltd | Real estate | 2012 |
| Cherwell Consulting Ltd | Administrative & support | 2013 |
| Chester Arms Limited | Hospitality | 2013 |
| Chestnut on the Water Ltd | Hospitality | 2021 |
| Chestnut Walk (Worcester) Management Company Limited | Households | 2004 |
| CHF Farming & Equestrian Limited | Real estate | 2025 |
| Chiara Perera Jewellery Ltd | Manufacturing | 2025 |
| Chillaire Isis Limited | Manufacturing | 1981 |
| Chiltern Solar Holding Company Limited | Construction | 2023 |
| Chiltern Solar Limited | Construction | 2011 |
| Chocolate Edit Ltd | Extraterritorial | 2018 |
| Choice Game Ltd | Agriculture & fishing | 2024 |
| Chorleywood Research Limited | Other services | 1994 |
| Chorus Independent Financial Planning Ltd | Financial services | 2018 |
| Chown Plumbing and Heating Limited | Construction | 2025 |
| CHP Equestrian Limited | Agriculture & fishing | 2025 |
| Chris Badger Commercial Finance Limited | Financial services | 2021 |
| Chris Brooks Electrical Services Limited | Construction | 2015 |
| Chris Hall IT Consultancy Limited | Information & communication | 2014 |
| Christchurch Homes Limited | Financial services | 2018 |
| Christian Nelson Windows Doors and Conservatories Ltd | Construction | 2025 |
| Christopher Kalika Limited | Administrative & support | 2014 |
| Chrome Investment Holdco Limited | Financial services | 2025 |
| Chuck - the Documentary Ltd | Information & communication | 2017 |
| Chunk Pubs Ltd | Hospitality | 2023 |
| Church Green Dental Practice Ltd | Health & social care | 2025 |
| Churston Property Maintenance Ltd | Construction | 2017 |
| Chvc Holdings Limited | Financial services | 2025 |
| Cinnamon Property Developments Limited | Real estate | 2019 |
| Cinnamon Quarter Limited | Real estate | 2019 |
| Cipri Spot Limited | Hospitality | 2024 |
| Cirriform Services Limited | Information & communication | 2012 |
| Cisurv Group Ltd | Financial services | 2026 |
| Citidata Limited | Professional & scientific | 1979 |
| Citizen Bird Limited | Professional & scientific | 2016 |
| Citizens Advice Oxfordshire | Health & social care | 2002 |
| City & County Refrigeration and Air Conditioning Limited | Manufacturing | 2018 |
| City Farm Management Company Limited | Households | 2005 |
| City of Oxford Swimming Club | Arts & recreation | 2018 |
| CJ Cleaning Services (Oxford) Ltd | Administrative & support | 2019 |
| Cjb-Project Services Ltd | Professional & scientific | 2026 |
| CJM Roofing & Property Maintenance Ltd | Construction | 2020 |
| Clandev Ltd | Construction | 2025 |
| Clarity Leadership Limited | Administrative & support | 2009 |
| Clarkevanmeurs Design Limited | Professional & scientific | 2012 |
| Classic Flowers Limited | Wholesale & retail | 2010 |
| Classical Communications Limited | Information & communication | 1997 |
| Clean Nutrition Ltd | Wholesale & retail | 2021 |
| Clean Sister Clean Ltd | Administrative & support | 2018 |
| Clean Solution Oxon Ltd | Administrative & support | 2014 |
| Clearsight Energy Ltd | Professional & scientific | 2019 |
| Clearways Prolog ( UK ) Ltd | Transport & logistics | 2016 |
| CLG Resourcing Limited | Administrative & support | 2016 |
| Climent Smiles Ltd | Health & social care | 2020 |
| Clincher Limited | Professional & scientific | 2019 |
| Clipper Development Partners LLP | | 2012 |
| Clock Workshop (Witney) Limited | Other services | 2018 |
| Clockwork Components Limited | Wholesale & retail | 2004 |
| Clockwork Holdings Limited | Wholesale & retail | 1999 |
| Cloud Transform Ltd | Information & communication | 2025 |
| Cloudify Legal Ltd | Information & communication | 2021 |