| Jason Tearne Tree Surgery Limited | Administrative & support | 2007 |
| Jaywynne Ince Limited | Real estate | 2021 |
| Jaywynne Limited | Administrative & support | 2018 |
| JB Civil Engineering Ltd | Construction | 2009 |
| JBY Holdings Limited | Financial services | 2016 |
| JBY Property Ltd | Real estate | 2025 |
| JC & IC Ferguson Limited | Households | 1992 |
| JC Painting Services Ltd | Construction | 2023 |
| JC Theatrical Installations Ltd | Construction | 2024 |
| JCM & S Properties Ltd | Real estate | 2025 |
| JCP Group Ltd | Financial services | 2018 |
| JCR Commercials Ltd | Wholesale & retail | 2018 |
| Jd&H Properties Limited | Construction | 2017 |
| JDM Solutions | Professional & scientific | 2005 |
| Jennifer Mousley Independent Funeral Director Ltd | Other services | 2022 |
| Jerry@ UFS Ltd | Wholesale & retail | 2018 |
| Jetarrow Ltd | Transport & logistics | 2025 |
| Jewels & Gems Ltd | Wholesale & retail | 2026 |
| Jeyes Mechanical Handling Limited | Manufacturing | 2017 |
| Jfcs Investments Limited | Real estate | 2009 |
| JG Transport (Leicester) Limited | Transport & logistics | 2018 |
| JGM Agencies Limited | Wholesale & retail | 2012 |
| JHM Gaming Limited | Arts & recreation | 2017 |
| Jill Ezard Consulting Limited | Professional & scientific | 2025 |
| JJB Building Services Limited | Construction | 2023 |
| JJE Agricultural Services Ltd | Agriculture & fishing | 2025 |
| Jjmd Engineering Limited | Professional & scientific | 2022 |
| Jkkd Investments Ltd | Real estate | 2025 |
| JL Creative Solutions Ltd | Manufacturing | 2024 |
| JLA Bespoke Investments Ltd | Real estate | 2025 |
| JLH Capital Limited | Financial services | 2021 |
| JLO Computer Science Limited | Professional & scientific | 2023 |
| Jlpm (East Midlands) Limited | Financial services | 2019 |
| Jmatch Limited | Administrative & support | 2013 |
| JMC Consulting (International) Ltd | Administrative & support | 2010 |
| JN & AJ Austin Limited | Agriculture & fishing | 2012 |
| JN Nails Ltd | Other services | 2016 |
| Joanna Stroinska Ltd | Manufacturing | 2020 |
| Joanne Rowley Limited | Professional & scientific | 2013 |
| Joe's Lawn Care Ltd | Administrative & support | 2015 |
| John Hill Coach Sales Ltd | Wholesale & retail | 2022 |
| Joleleo Supply Ltd | Wholesale & retail | 2025 |
| Jomon Ltd | Professional & scientific | 2025 |
| Jones Equine Transport Limited | Transport & logistics | 2025 |
| Josef E Zbaraski Ltd | Professional & scientific | 2006 |
| Joshua Allis Enterprise Limited | Health & social care | 2018 |
| JPS Electrical Limited | Construction | 2021 |
| JQ Leics Limited | Arts & recreation | 2025 |
| Jrjf Management Ltd | Professional & scientific | 2025 |
| JRT Property Estates Ltd | Real estate | 2025 |
| Jsmcn Property Ltd | Real estate | 2024 |
| JT Fabrications (Leics) Limited | Manufacturing | 1995 |
| Jubilee Asset Management Limited | Extraterritorial | 2000 |
| Julia Oliphant Ltd | Professional & scientific | 2024 |
| Jungle Bugs Ltd | Arts & recreation | 2018 |
| Junor Ltd | Agriculture & fishing | 2018 |
| Just Another Salon !!! Limited | Other services | 2014 |
| Just the Right Thing Limited | Wholesale & retail | 2016 |
| JW Global Education Ltd | Education | 2023 |
| JWS Consulting Ltd | Professional & scientific | 2025 |
| K & M Interiors Ltd | Construction | 2014 |
| K Burger (Midlands) Ltd | Hospitality | 2024 |
| K J Civils & Construction Ltd | Construction | 2021 |
| K P Roofing (Leicester) Limited | Construction | 2009 |
| K& a Connolly Construction Limited | Construction | 2014 |
| K.A Car Sales Ltd | Wholesale & retail | 2024 |
| K.S. Composites Limited | Manufacturing | 2002 |
| Ka&Er Ltd | Administrative & support | 2020 |
| Kabrit Group Limited | Other services | 2015 |
| Kaia Beach Vista Limited | Real estate | 2017 |
| Kantala Limited | Information & communication | 2004 |
| Kaonde Sounds Ltd | Information & communication | 2025 |
| Kapela Transport Ltd | Transport & logistics | 2023 |
| Karmod International Ltd | Construction | 2018 |
| Kate Hill Recruitment Limited | Administrative & support | 2024 |
| Katie's Classroom Tutoring Ltd | Education | 2023 |
| KB Road Haulage Ltd | Transport & logistics | 2023 |
| Kburgers Melton Limited | Hospitality | 2026 |
| Keightley Pattison Financial Management Limited | Financial services | 2008 |
| Keightley Pattison Legal Services Limited | Other services | 2012 |
| Keith Bottom Plumbing & Heating Ltd | Construction | 2014 |
| Keto Munch Ltd | Hospitality | 2024 |
| Kettleby Solutions Limited | Manufacturing | 2011 |
| Kevin Hall Security Ltd | Construction | 2024 |
| Kewrnat Limited | Wholesale & retail | 2026 |
| Key Developments (Oakham) Ltd | Construction | 2025 |
| Key Farms Ltd | Agriculture & fishing | 2021 |
| Keystone Vale Limited | Construction | 2015 |
| Keyworth Farm LLP | | 2014 |
| KHB Bookkeeping Services Ltd | Professional & scientific | 2021 |
| Khela Transport Limited | Transport & logistics | 2018 |
| Khumbu Limited | Real estate | 2025 |
| Kindtwo Consulting Ltd | Professional & scientific | 2023 |
| Kinetic GB2 Ltd | Professional & scientific | 2024 |
| Kingfisher Court (Melton) Management Company Limited | Households | 2000 |
| Kingfisher Developments & Projects Limited | Construction | 2026 |
| Kirby AG Ltd | Manufacturing | 2019 |
| Kirby Bellars Fisheries Limited | Wholesale & retail | 2025 |
| Kirby Bellars Holdings Limited | Financial services | 2025 |
| Kirby Coach House Limited | Real estate | 2019 |