| John Holland Psychologists Ltd | Professional & scientific | 2007 |
| John Howlett Planning Limited | Professional & scientific | 2018 |
| John Jefferson Media Projects Limited | Information & communication | 2006 |
| John Marlow Limited | Professional & scientific | 1983 |
| John Maunders Group Limited | Professional & scientific | 1968 |
| John Moran & Sons (Grimsby) Limited | Real estate | 2007 |
| John Pilley Properties Limited | Financial services | 1921 |
| John Rook Estates Limited | Agriculture & fishing | 2023 |
| John Rook Holdings Limited | Agriculture & fishing | 2023 |
| John Tomsett Educational Consultancy Limited | Education | 2015 |
| John Wilson (Builder) Limited | Construction | 2006 |
| John Wright Electrical & Mechanical Services Limited | Construction | 1997 |
| John Wright Group Ltd | Manufacturing | 2022 |
| John's Meadow Management Company Limited | Households | 2021 |
| Johnny Sugar Ltd | Professional & scientific | 2025 |
| Johnson Agri Ltd | Professional & scientific | 2025 |
| Johnson Editorial Services Limited | Information & communication | 2017 |
| Johnson Horsman Ltd | Real estate | 2022 |
| Johnson Massey Developments Limited | Real estate | 2019 |
| Johnson's Heating & Plumbing Limited | Construction | 2008 |
| Johnsonmccoy Enterprises Ltd | Financial services | 2021 |
| Johnsons Nurseries (Cattal) Limited | Real estate | 2018 |
| Johnsons Nurseries (Holdings) Limited | Financial services | 2018 |
| Johnsons Nurseries (Newlands) Limited | Real estate | 2018 |
| Johnsons Nurseries (Roecliffe) Limited | Real estate | 2018 |
| Johnsons Nurseries (Thornville) Limited | Real estate | 2018 |
| Johnsons Nurseries Limited | Agriculture & fishing | 1958 |
| Joiner Consultants Ltd | Professional & scientific | 2016 |
| Joiners Yard Ltd | Real estate | 2025 |
| Joinstep Property Management Limited | Households | 1990 |
| Jolly Good Business Limited | Information & communication | 2006 |
| Jolly Good Software Limited | Information & communication | 2006 |
| Jollydays Luxury Camping Limited | Hospitality | 2009 |
| Jolst Limited | Real estate | 2023 |
| Jomacolt Automobiles Ltd | Wholesale & retail | 2026 |
| Jomacolt Global Resources Limited | Wholesale & retail | 2024 |
| JON Bell Counselling & Sports Psychotherapy Ltd | Health & social care | 2021 |
| JON Burgess Ltd | Wholesale & retail | 2012 |
| JON Hatfield Limited | Manufacturing | 2010 |
| Jonade Homes Ltd | Real estate | 2018 |
| Jonas Trading Ltd | Wholesale & retail | 2012 |
| Jonathan Brown Media Ltd | Information & communication | 2026 |
| Jonathan Owen (Leeds) Limited | Health & social care | 2014 |
| Jonathan Wood Limited | Professional & scientific | 2004 |
| Jonathangreen.Eu Limited | Manufacturing | 2017 |
| Jones & Co of York Limited | Professional & scientific | 2004 |
| Jones Bootmaker Limited | Wholesale & retail | 2020 |
| Jordan Bacon Ltd | Real estate | 2022 |
| Jordan's Garage York Limited | Wholesale & retail | 2025 |
| Jordanh Photography Ltd | Professional & scientific | 2025 |
| Jordans Transport Limited | Other services | 2002 |
| Jorko Ltd | Other services | 2025 |
| Jorvik Accountancy Services Limited | Extraterritorial | 2014 |
| Jorvik Accountants Limited | Extraterritorial | 2014 |
| Jorvik Advisory Services Limited | Professional & scientific | 2025 |
| Jorvik Carpets & Floorings Ltd | Wholesale & retail | 2016 |
| Jorvik Consultancy York Limited | Professional & scientific | 2022 |
| Jorvik Consulting Ltd | Administrative & support | 2007 |
| Jorvik Developments Ltd | Extraterritorial | 2020 |
| Jorvik Embroidery Ltd | Wholesale & retail | 2024 |
| Jorvik Estate Co. Limited | Agriculture & fishing | 2023 |
| Jorvik Estate Planning Ltd | Professional & scientific | 2026 |
| Jorvik Fire and Security Ltd | Administrative & support | 2020 |
| Jorvik Food & Environmental Virology Ltd | Professional & scientific | 2017 |
| Jorvik Investment Ltd | Real estate | 2021 |
| Jorvik Media Ltd | Information & communication | 2022 |
| Jorvik Motor Leasing Limited | Administrative & support | 2013 |
| Jorvik Project Services Ltd | Professional & scientific | 2023 |
| Jorvik Property Development Ltd | Real estate | 2022 |
| Jorvik Property Ltd | Real estate | 2017 |
| Jorvik Radio Limited | Information & communication | 2017 |
| Jorvik Refrigeration Limited | Other services | 2016 |
| Jorvik Removals & Self Storage Ltd | Transport & logistics | 2016 |
| Jorvik Security Group Limited | Administrative & support | 2023 |
| Jorvik Smile Limited | Health & social care | 2017 |
| Jorvik Tipis LP | | 2022 |
| Jorvik Transformation Services Ltd | Professional & scientific | 2017 |
| Jorvik Travel Ltd | Transport & logistics | 2025 |
| Jorvik Tricycles of York Limited | Wholesale & retail | 2020 |
| Jorvik Van Conversions Limited | Manufacturing | 2021 |
| Jorvik Villa Ltd | Extraterritorial | 2021 |
| Jorvikhottubhire Ltd | Administrative & support | 2025 |
| Jorvikrail Ltd | Transport & logistics | 2021 |
| Joseph Henry 21 Limited | Financial services | 2022 |
| Joseph Jane Ltd | Administrative & support | 2026 |
| Joseph Moore Limited | Hospitality | 2012 |
| Joseph Rowntree Foundation | Health & social care | 2019 |
| Josh Wilford Sales Management Ltd | Professional & scientific | 2024 |
| Josoph Corporate Services Limited | Administrative & support | 2019 |
| Jossa Property Ltd | Real estate | 2025 |
| Jotinx Limited | Construction | 2003 |
| JOURNEY4 Limited | Professional & scientific | 2002 |
| Joy Commercial Limited | Professional & scientific | 2026 |
| Joy Information Service Ltd | Wholesale & retail | 2024 |
| Joy Passion Works Ltd | Real estate | 2022 |
| Joyomagrv Ltd | Wholesale & retail | 2026 |
| JP & AJ Gill Limited | Agriculture & fishing | 2011 |
| JP C&C Limited | Wholesale & retail | 2023 |
| JP Commercial Vehicles Limited | Wholesale & retail | 2021 |
| JP French International Limited | Professional & scientific | 2025 |