| Cutting Fitness Ltd | Education | 2022 |
| Cutting the Costs of Frailty Limited | Health & social care | 2016 |
| Cutts Bespoke Joinery Ltd | Construction | 2026 |
| Cutts Brothers Engineering Limited | Manufacturing | 1999 |
| Cutts Construction Ltd | Construction | 2023 |
| Cutts Property Management Ltd | Real estate | 2024 |
| Cutts Storage Ltd | Real estate | 2024 |
| Cuzco Restaurants Limited | Hospitality | 2010 |
| CVC Event Services Limited | Information & communication | 2003 |
| CVC Worldwide Limited | Administrative & support | 2023 |
| Cvmastermind Limited | Information & communication | 2025 |
| CW Flooring Specialists Ltd | Construction | 2021 |
| CW Interiors (Yorkshire) Ltd | Construction | 2018 |
| CW Land and Properties Ltd | Real estate | 2026 |
| CW Machine Services Limited | Manufacturing | 2025 |
| CW Plumbing & Heating (Sheffield) Limited | Construction | 2007 |
| CW Sales & Lettings Ltd | Real estate | 2024 |
| CW Strive Limited | Arts & recreation | 2026 |
| CWG Holdings Ltd | Financial services | 2022 |
| CWH Contracting Limited | Other services | 2024 |
| Cwmw Ltd | Real estate | 2026 |
| Cwna Smith Limited | Construction | 2023 |
| CWS Rentals Ltd | Administrative & support | 2024 |
| CWS Wellbeing Centre Ltd | Arts & recreation | 2023 |
| Cwsuk Ltd | Other services | 2021 |
| CX Bidco Limited | Health & social care | 2016 |
| CX Midco 2 Limited | Health & social care | 2016 |
| CX Midco Limited | Health & social care | 2016 |
| CX Topco Limited | Health & social care | 2016 |
| CXO Media Group Ltd | Professional & scientific | 2021 |
| Cyangold Limited | Administrative & support | 2003 |
| Cyber Ranges Group Limited | Information & communication | 2025 |
| Cyber Ranges UK and Ireland Ltd | Information & communication | 2006 |
| Cyberfuse LLP | | 2024 |
| Cyberkarl Limited | Information & communication | 2024 |
| Cybermerge Systems Limited | Information & communication | 2025 |
| Cybertechnics Limited | Information & communication | 1998 |
| Cybpass Limited | Information & communication | 2025 |
| Cycle Buyer Limited | Wholesale & retail | 2022 |
| Cycle Transfer (Europe) Limited | Transport & logistics | 2016 |
| Cycling Sheffield Limited | Arts & recreation | 2018 |
| Cydonia Systems Limited | Information & communication | 2014 |
| Cygenta Limited | Information & communication | 2014 |
| Cygnus Capital Holdings Ltd | Financial services | 2020 |
| CYJ Joinery Ltd | Construction | 2022 |
| Cyktor Property Ltd | Real estate | 2025 |
| Cylk Limited | Information & communication | 2024 |
| Cynosure Fashion and Beauty UK Ltd | Other services | 2026 |
| Cynosure Management Limited | Financial services | 2023 |
| Cynthia Care Limited | Health & social care | 2025 |
| Cynthiaswigs Ltd | Other services | 2025 |
| CZL Consulting Limited | Wholesale & retail | 2019 |
| D & a J Crookes Ltd | Real estate | 2014 |
| D & C Hobbs Property Ltd | Real estate | 2017 |
| D & J Autos Limited | Wholesale & retail | 1981 |
| D & J Holdings Limited | Financial services | 2023 |
| D & L Couriers Ltd | Transport & logistics | 2014 |
| D & L Hinchliffe Accountancy Limited | Professional & scientific | 2022 |
| D & N Civil Engineering Limited | Construction | 2023 |
| D & N Property Development Ltd | Construction | 2026 |
| D & N Sheffield Limited | Construction | 2005 |
| D & P Joinery Ltd | Construction | 2013 |
| D & S Accountants Ltd | Professional & scientific | 2010 |
| D a Rowley (S.Y.) Ltd | Construction | 2007 |
| D a Waite Limited | Administrative & support | 2013 |
| D Adams Accountants Ltd | Professional & scientific | 2019 |
| D and L Castle Limited | Construction | 2015 |
| D and P Media Walls and Fires Limited | Wholesale & retail | 2025 |
| D Andrews RDH RDT Limited | Health & social care | 2013 |
| D B Engineering Harthill Limited | Manufacturing | 2011 |
| D B Fabrications & Site Services Limited | Manufacturing | 2016 |
| D Ball Window Cleaning Ltd | Administrative & support | 2024 |
| D Benbow Brickwork Ltd | Construction | 2025 |
| D C Bathrooms Ltd | Construction | 2019 |
| D C Douglas Construction Ltd | Construction | 2020 |
| D C Heating (South Yorkshire) Ltd | Construction | 2019 |
| D Collection Limited | Real estate | 2013 |
| D Dixon Builders Ltd | Construction | 2018 |
| D E Leece Limited | Extraterritorial | 2014 |
| D Fallaize Limited | Hospitality | 2015 |
| D Fenoughty Consulting Ltd | Professional & scientific | 2025 |
| D G Broker Ltd | Transport & logistics | 2025 |
| D G Doors and Windows Ltd | Construction | 2013 |
| D Goodall & SON Limited | Construction | 2012 |
| D H Scaffold Services Limited | Construction | 2013 |
| D Horsfield Electrical Limited | Construction | 2024 |
| D Howe Haulage Limited | Transport & logistics | 2015 |
| D J Allen Plumbing & Heating Limited | Construction | 2014 |
| D J Clarke Brickworks Ltd | Construction | 2018 |
| D J Diving Consultancy Ltd | Professional & scientific | 2021 |
| D J Maccalan Limited | Wholesale & retail | 2020 |
| D K Model Management Limited | Administrative & support | 2009 |
| D L Marshall Holdings Ltd | Manufacturing | 2018 |
| D M Elite Ltd | Information & communication | 2015 |
| D M Leigh Limited | Construction | 2012 |
| D M Mirfin Limited | Financial services | 2019 |
| D M Reinforcements Ltd | Construction | 2024 |
| D M Roberts Limited | Information & communication | 2009 |
| D Neves Removal Ltd | Transport & logistics | 2025 |
| D O Flaherty Limited | Construction | 2013 |