| JOC Consultants Limited | Professional & scientific | 2007 |
| John Brown Builders Yorkshire Ltd | Construction | 2020 |
| John Lydamore Ltd | Professional & scientific | 2014 |
| Johnson Corporation (Joco) Limited | Extraterritorial | 1959 |
| Johnsons of Otley Self Storage Limited | Real estate | 2017 |
| Jolly Taverns & Inns Ltd | Hospitality | 2025 |
| Joyd Studios Ltd | Information & communication | 2024 |
| Jozan Limited | Manufacturing | 2011 |
| Jppl Ltd | Construction | 2021 |
| Jpwestmoreland Property Ltd | Real estate | 2020 |
| JS Thompson Properties Ltd | Construction | 2024 |
| JSC Joinery (Yorkshire) Limited | Construction | 2024 |
| JTB Audio Ltd | Wholesale & retail | 2004 |
| Jurgen Kaiser Wines LLP | | 2012 |
| Just Commercial Boilers Ltd | Construction | 2025 |
| Just OIL Boilers Ltd | Construction | 2024 |
| Justpubsandclubs Limited | Professional & scientific | 2019 |
| K & a Fabrications Ltd. | Manufacturing | 2008 |
| K & M Property North East Limited | Real estate | 2016 |
| K Glazing & Maintenance Limited | Construction | 2014 |
| K Hurrell IR Limited | Arts & recreation | 2019 |
| K Watkins IR Limited | Arts & recreation | 2013 |
| Kadant Johnson Systems International Limited | Professional & scientific | 1999 |
| Kakuli 62 Limited | Administrative & support | 2017 |
| Kamposioras Ltd | Health & social care | 2021 |
| Kaprinis Medical Ltd | Health & social care | 2024 |
| Kaye & Co Accountants Ltd | Professional & scientific | 2025 |
| Keighley Model Railway Club | Other services | 2008 |
| Kelida Holdings Ltd | Financial services | 2022 |
| Kelida Solutions Limited | Administrative & support | 2012 |
| KEN Creek Bookkeeping Limited | Professional & scientific | 2021 |
| Kendrick Falls Ltd | Wholesale & retail | 2019 |
| Kerry Court Management Company Limited | Households | 1990 |
| Key to Key Limited | Other services | 2016 |
| Kidstones Limited | Professional & scientific | 2016 |
| KIN Care Ltd | Health & social care | 2022 |
| Kinaya Solutions Ltd | Professional & scientific | 2018 |
| Kingdom Gardens (Wharfedale) Limited | Professional & scientific | 2011 |
| Kinsey Group Limited | Professional & scientific | 2024 |
| Kirkfield Consultants Limited | Hospitality | 2023 |
| Kirkgate Wholesale Trading Limited | Wholesale & retail | 2000 |
| Kirwin Air Conditioning Limited | Manufacturing | 2000 |
| KNG Financial Management LLP | | 2008 |
| Kodama UK Ltd | Other services | 2024 |
| Korsync Limited | Information & communication | 2019 |
| Koti Creative Design Limited | Construction | 2024 |
| Krustys Bike Barn Ltd | Wholesale & retail | 2023 |
| KTM Trading Foods Ltd | Wholesale & retail | 2022 |
| KTM Trading Leeds Limited | Wholesale & retail | 2019 |
| L & J Property Limited | Real estate | 2009 |
| Ladrillo Ltd | Real estate | 2021 |
| Lakeside Helicopters Ltd | Wholesale & retail | 2019 |
| Landguard Ltd | Administrative & support | 2018 |
| Lane Clinic Limited | Extraterritorial | 1987 |
| Lapin Holdings Limited | Real estate | 2026 |
| Later Life Finance Limited | Financial services | 2014 |
| Laurence Campbell Interiors Ltd | Construction | 2025 |
| LDR Systems Ltd | Construction | 2019 |
| LEAFUS2IT Ltd | Administrative & support | 2020 |
| Leafy Couture Franchising Limited | Other services | 2022 |
| Lean Manufacturing and Training Limited | Administrative & support | 2013 |
| Learning Landscapes Limited | Construction | 2010 |
| Leathley Farm Shop and Cafe Ltd | Wholesale & retail | 2021 |
| Leeds Events Team Limited | Administrative & support | 2024 |
| Lensmill Limited | Real estate | 1985 |
| Leodis Compliance Management Ltd | Other services | 2022 |
| Leodis Developments Ltd | Construction | 2014 |
| Leodis Group Ltd | Financial services | 2023 |
| Leodis M&E Ltd | Construction | 2020 |
| Leodis Plumbing & Heating Limited | Construction | 2022 |
| Lesa Brown Limited | Real estate | 2017 |
| Liberty Home Support Service Limited | Health & social care | 2014 |
| Liberty Support Limited | Health & social care | 2010 |
| Lightyear Property Enterprises 2 Ltd | Real estate | 2025 |
| Lightyear Property Enterprises Ltd | Real estate | 2023 |
| Limestone Projects Ltd | Real estate | 2025 |
| Limitless Play Ltd | Construction | 2022 |
| Lincus Healthcare Limited | Extraterritorial | 2017 |
| Linden Court Flats Limited | Households | 1968 |
| Little Munchkins of Otley Limited | Wholesale & retail | 2016 |
| Littlewood Orthodontics Ltd | Health & social care | 2014 |
| Livra-Libre Limited | Wholesale & retail | 2026 |
| Lizzie Armitstead Ltd | Arts & recreation | 2011 |
| LJM Groundworks & Design Limited | Administrative & support | 2016 |
| Ljng Limited | Wholesale & retail | 2025 |
| LKB HR Consulting Ltd | Administrative & support | 2021 |
| Llml Ltd | Administrative & support | 2024 |
| Lloyd Almond Productions Limited | Information & communication | 2012 |
| LLS Entertainment Ltd | Information & communication | 2025 |
| LMJ Property Limited | Real estate | 2023 |
| Lneg C.I.C. | Other services | 2024 |
| LOGOS2GO Ltd | Manufacturing | 2017 |
| Louchri Limited | Real estate | 2000 |
| Lund of Otley (Furnishings) Limited | Wholesale & retail | 1976 |
| Luxury Hair Products Ltd | Wholesale & retail | 2024 |
| M G Mellor Accountancy Services Limited | Professional & scientific | 2015 |
| M Pervas Ltd | Wholesale & retail | 2025 |
| M.S. Render Specialist Limited | Construction | 2013 |
| M13 Skills Associates Limited | Professional & scientific | 2014 |
| Macauley Motors Ltd | Wholesale & retail | 2025 |