| John P Anderson Ltd. | Administrative & support | 2024 |
| John Peter Ayres Ltd | Extraterritorial | 2025 |
| John Prosser Ltd | Education | 2024 |
| John Quinn and Sons Car Transport Limited | Transport & logistics | 1992 |
| John Ryan Consulting Limited | Information & communication | 2024 |
| John Sinclair (Sheffield) Limited | Wholesale & retail | 1966 |
| John ST Kitchen Ltd | Hospitality | 2020 |
| John Stenson Ltd | Transport & logistics | 2022 |
| John Street Galvanizing Limited | Manufacturing | 2013 |
| John Street Platers Limited | Professional & scientific | 1996 |
| John Vardy Woodworking Ltd | Construction | 2018 |
| John Vincent Marketing Services Limited | Administrative & support | 2004 |
| John Warren (Animal By-Products) Ltd | Water & waste | 2019 |
| John Whitmore Electrical Contractors Ltd | Construction | 2013 |
| John Wilson Skates Limited | Professional & scientific | 1979 |
| John Wilson, Marsden Bros. & Co. Limited | Professional & scientific | 1986 |
| John Wragg & Company,Limited | Wholesale & retail | 1907 |
| Johndot Properties Ltd | Real estate | 2021 |
| Johnny Drivers Limited | Transport & logistics | 2018 |
| Johnnygate Cottages Limited | Financial services | 2018 |
| Johns Van Catering Limited | Hospitality | 2022 |
| Johnson & Allen Limited | Manufacturing | 1938 |
| Johnson and Johnson Couriers Ltd | Transport & logistics | 2020 |
| Johnson Brothers (Motors) Limited | Wholesale & retail | 2025 |
| Johnson Creation Limited | Wholesale & retail | 2022 |
| Johnson Emmens Consultancy & Training Limited | Professional & scientific | 2023 |
| Johnson Mechanical Project Services Limited | Professional & scientific | 2025 |
| Johnson Property Rentals Ltd | Real estate | 2018 |
| Johnson Purba Limited | Professional & scientific | 2011 |
| Johnsons Courtyard MC Limited | Households | 2023 |
| Johnsons Property Services Group Limited | Construction | 2020 |
| Johnstone Construction Management Limited | Construction | 2020 |
| Johnstones Furniture Limited | Manufacturing | 2003 |
| Johnstonpropertyinvestments Ltd | Financial services | 2022 |
| Johnstun Ltd | Health & social care | 2026 |
| Join Frames Ltd | Manufacturing | 2022 |
| Join the Claim Limited | Administrative & support | 2025 |
| Join the Dots Agency Ltd | Professional & scientific | 2021 |
| Joinery Bar Ltd | Hospitality | 2025 |
| Joint Harmony Ltd | Health & social care | 2022 |
| Joint Replacement Instrumentation Limited | Professional & scientific | 1988 |
| Jokemkan Technologies Ltd | Information & communication | 2025 |
| Jokur Holdings Limited | Wholesale & retail | 2022 |
| Jollie Ltd | Wholesale & retail | 2023 |
| Jolly & Hotchen Developments 33HSR Limited | Real estate | 2025 |
| Jolly & Hotchen Developments Holdco Limited | Financial services | 2025 |
| Jolly Barks and Play LLP | | 2024 |
| Jolly IT Solutions Limited | Information & communication | 2006 |
| Jolly Property Investments Limited | Real estate | 2024 |
| Jolly Property Mentoring Limited | Professional & scientific | 2024 |
| Jolt ML Ltd | Information & communication | 2022 |
| Jolydex Multi Services Ltd | Wholesale & retail | 2025 |
| Jomark Electrical Ltd | Construction | 2026 |
| Jomax Leisure and Catering Ltd | Hospitality | 2025 |
| Jomo Electrical Services Ltd | Construction | 2024 |
| JON Anger Engraving Limited | Manufacturing | 2019 |
| JON Clark Reward Consulting Limited | Professional & scientific | 2018 |
| JON COE Tree Consultancy Ltd | Agriculture & fishing | 2015 |
| JON Colegate Limited | Information & communication | 2009 |
| JON Garcia Consulting Limited | Professional & scientific | 2015 |
| JON Harrison (Design) Limited | Manufacturing | 2012 |
| JON Jacobs Limited | Information & communication | 2003 |
| JON Mawson Limited | Administrative & support | 2007 |
| JON Pullins Amusements Sheffield Limited | Arts & recreation | 2016 |
| JON Spacie Signs Limited | Manufacturing | 1998 |
| JON Stacey Golf Limited | Arts & recreation | 2022 |
| JON Wellard Ltd | Information & communication | 2026 |
| Jonas Health Care Ltd | Health & social care | 2019 |
| Jonat Ltd. | Construction | 2019 |
| Jonathan Clements Architects Ltd | Professional & scientific | 2017 |
| Jonathan Greaves Development Ltd | Information & communication | 2025 |
| Jonathan Huddersfield Helm Ltd | Administrative & support | 2011 |
| Jonathan LEE Consultancy (Tax) Limited | Professional & scientific | 2000 |
| Jonathan LEE Consultancy (Trustees) Ltd | Professional & scientific | 2016 |
| Jonathan Manley Limited | Professional & scientific | 2014 |
| Jonc Solutions Limited | Professional & scientific | 2024 |
| Jones & Jones Investments Limited | Real estate | 2023 |
| Jones & Rear Limited | Hospitality | 2017 |
| Jones & Street Ltd | Hospitality | 2025 |
| Jones Building Solutions Ltd | Construction | 2017 |
| Jones Family Dental Limited | Health & social care | 2014 |
| Jones Francis Limited | Professional & scientific | 2016 |
| Jones Lovin' Homes Ltd | Real estate | 2025 |
| Jones Services Ltd | Construction | 2025 |
| Jonkel Ltd | Wholesale & retail | 2024 |
| Jonny Browns Professional Property Photography Ltd | Professional & scientific | 2023 |
| Jonny Smart Ltd | Arts & recreation | 2015 |
| Jonny Trade Ltd | Wholesale & retail | 2020 |
| Jonny WAN Illustration Limited | Arts & recreation | 2019 |
| Jono Thompson Properties Ltd | Real estate | 2017 |
| Joof Ltd | Education | 2024 |
| Jorand Limited | Real estate | 2002 |
| Jordan Haver Ltd | Wholesale & retail | 2024 |
| Jordan LTS Limited | Information & communication | 2019 |
| Jordan Mini Market Ltd | Wholesale & retail | 2025 |
| Jordan Wasden and Sons Property Developments Ltd | Real estate | 2023 |
| Jordan Wedge Limited | Extraterritorial | 2004 |
| Jordan Wheelhouse Estates Limited | Real estate | 2025 |
| Jordanna Nichols Ltd | Other services | 2015 |
| Jordanthorpe Food & Wine Ltd | Wholesale & retail | 2010 |