| J S Warwick Associates Limited | Information & communication | 2007 |
| J Tucker Plumbing Limited | Construction | 2006 |
| J. Marr (DRY Foods) Limited | Administrative & support | 2020 |
| J. Marr (Grimsby) Limited | Extraterritorial | 1936 |
| J. Marr (Sea Products) Limited | Extraterritorial | 1955 |
| J. Marr (Seafoods) Limited | Agriculture & fishing | 1924 |
| J. Marr Seafoods (Holdings) Limited | Extraterritorial | 1960 |
| J. Marr Seafoods (Ship Services) Limited | Extraterritorial | 1923 |
| J.B. Timber Importers Limited | Manufacturing | 2001 |
| J.E. Sowden Limited | Extraterritorial | 1947 |
| J.Fletcher & SON (Hull) Limited | Real estate | 1953 |
| J.Wardle & SON Limited | Wholesale & retail | 1930 |
| Jackson Robson (32) Ltd | Professional & scientific | 1986 |
| Jackson Robson Licence Limited | Professional & scientific | 2006 |
| Jackson Street Motors Limited | Wholesale & retail | 1997 |
| James Wight (Hull) Limited | Extraterritorial | 1950 |
| Jaymarr (Seafoods) Limited | Extraterritorial | 1976 |
| Jefferson Electrical Limited | Construction | 2002 |
| JEM Osgodby Limited | Real estate | 2004 |
| Jigsaw Learning Ltd | Information & communication | 2004 |
| John P. Dennis & SON Limited | Real estate | 1975 |
| John Robinson Consultants Limited | Financial services | 1997 |
| John Sullivan (Hornsea) Limited | Hospitality | 1990 |
| Jordan & Company (Hull) Limited | Wholesale & retail | 1965 |
| JS Vehicle Inspection Ltd | Manufacturing | 2007 |
| K a S Erectors Limited | Construction | 2007 |
| K S Marine Limited | Transport & logistics | 2002 |
| K.A. DE Cobain Limited | Wholesale & retail | 1974 |
| Karlan Digital Limited | Manufacturing | 2002 |
| KCH (Holdings) Limited | Professional & scientific | 2007 |
| Kcom Contact Centres Limited | Information & communication | 1999 |
| Kcom Group Limited | Information & communication | 1987 |
| Kcom Holdings Limited | Information & communication | 1997 |
| Kenley Management Services Limited | Agriculture & fishing | 2003 |
| Kerbside Productions Limited | Hospitality | 1995 |
| Kesford Limited | Construction | 2003 |
| Keystore Limited | Transport & logistics | 1985 |
| KFM Recruitment Limited | Administrative & support | 1987 |
| Kildale Marine Limited | Wholesale & retail | 2002 |
| Kingston Carton Company Limited(The) | Manufacturing | 1917 |
| Kingston Services Holdings Limited | Professional & scientific | 1998 |
| Kingston Square Properties Limited | Real estate | 1991 |
| Kingstown Plumbing Services Limited | Construction | 2002 |
| Knight Motorsport Engineering Limited | Wholesale & retail | 2006 |
| Konflux Theatre Limited | Arts & recreation | 2003 |
| Kristoffs (Cottingham) Limited | Hospitality | 2003 |
| L a Hall (Hull) Limited | Construction | 1999 |
| Lakestrand Limited | Real estate | 1988 |
| Lambert Clerical Limited | Professional & scientific | 2002 |
| Land Leisure NO.3 Limited | Professional & scientific | 1999 |
| Land of Green Ginger Design Limited | Professional & scientific | 1993 |
| Laranstone Limited | Professional & scientific | 2001 |
| Lasertrim Limited | Manufacturing | 1985 |
| Lawss Plaster and Building Services Ltd | Construction | 2005 |
| Laycock Garage Equipment Ltd | Wholesale & retail | 2005 |
| Leckonby Holdings Limited | Professional & scientific | 1999 |
| Leckonby Limited | Manufacturing | 1987 |
| LEE Johnson Limited | Real estate | 2025 |
| Leisure Technique Limited | Manufacturing | 1989 |
| Leonard Silver Limited | Wholesale & retail | 1975 |
| Little Tolly Properties Limited | Real estate | 2005 |
| Livingstone Seafoods Limited | Extraterritorial | 1953 |
| Local Transport Projects Limited | Professional & scientific | 2004 |
| Longman Jones Limited | Real estate | 2003 |
| Longtale Limited | Hospitality | 1998 |
| Loubek Blinds Limited | Wholesale & retail | 2002 |
| M&D Site Services Ltd | Construction | 2005 |
| M&H Specialist Joinery Limited | Construction | 2006 |
| M. Bielby Limited | Manufacturing | 1973 |
| M. Garton & SON Limited | Other services | 1986 |
| M.K.M. Building Supplies (Alnwick) Limited | Wholesale & retail | 2001 |
| M.K.M. Building Supplies (Burton Upon Trent) Limited | Wholesale & retail | 2018 |
| M.K.M. Building Supplies (Darlington) Limited | Wholesale & retail | 2001 |
| M.K.M. Building Supplies (Driffield) Limited | Wholesale & retail | 1996 |
| M.K.M. Building Supplies (Elgin) Limited | Wholesale & retail | 2018 |
| M.K.M. Building Supplies (Hartlepool) Limited | Wholesale & retail | 2007 |
| M.K.M. Building Supplies (Haverhill) Limited | Wholesale & retail | 2017 |
| M.K.M. Building Supplies (Holdings) Limited | Wholesale & retail | 2005 |
| M.K.M. Building Supplies (Hull) Limited | Wholesale & retail | 1998 |
| M.K.M. Building Supplies (Kilmarnock) Limited | Wholesale & retail | 2018 |
| M.K.M. Building Supplies (Leamington Spa) Limited | Wholesale & retail | 2017 |
| M.K.M. Building Supplies (Mansfield) Limited | Wholesale & retail | 2018 |
| M.K.M. Building Supplies (Morpeth) Limited | Wholesale & retail | 2002 |
| M.K.M. Building Supplies (Newent) Limited | Wholesale & retail | 2017 |
| M.K.M. Building Supplies (Norwich) Limited | Wholesale & retail | 2007 |
| M.R.H. (Yorkshire) Limited | Construction | 2002 |
| Macfarlane Thirsk Limited | Manufacturing | 1938 |
| Malcolm Johnson Homes Limited | Construction | 2001 |
| Maltings Property Management (Hull) Limited | Real estate | 2002 |
| Manor Delivery Services Limited | Transport & logistics | 2006 |
| Manor House (Ferriby) Management Limited | Households | 2000 |
| Manor Lodge (Hessle) Management Limited | Households | 2002 |
| Marco Polo Restaurants Limited | Hospitality | 2003 |
| Marine Valley Estate Limited | Real estate | 1988 |
| Marketability Direct Limited | Professional & scientific | 2003 |
| Marsden Builders Limited | Construction | 1972 |
| Marsden Estates Limited | Real estate | 1936 |
| Marshall Holdings (Hull) Limited | Real estate | 1962 |
| Marshalls Pest Prevention Limited | Other services | 2008 |
| Marton Manor Farm Limited | Agriculture & fishing | 2005 |