| Lime Close Management (Dorchester) Limited | Households | 1986 |
| Lime Green Beauty Ltd | Wholesale & retail | 2023 |
| Linden Court Dorchester Limited | Households | 2006 |
| Linden Gardens (Dorchester) Management Company Limited | Real estate | 2007 |
| Lindferx Limited | Wholesale & retail | 2025 |
| Lineartron Limited | Information & communication | 1987 |
| Linhall Ltd | Real estate | 2021 |
| Lionheart Consulting Limited | Other services | 2016 |
| Lipsticktowers Limited | Arts & recreation | 2020 |
| Lisa Jelly Ltd | Administrative & support | 2023 |
| Liscombe House (Poundbury) Management Company Limited | Households | 2015 |
| Little Angus Limited | Hospitality | 1987 |
| Little Birch Caravan Site Ltd | Hospitality | 2016 |
| Little Piddle Motors Ltd | Wholesale & retail | 2024 |
| Little Piddle Stores Ltd | Wholesale & retail | 2023 |
| Little Road Limited | Households | 2013 |
| Little Whale Properties Ltd | Hospitality | 2021 |
| Live Metrix Ltd | Professional & scientific | 2024 |
| Living History Films Ltd | Administrative & support | 2016 |
| LJ Thorne Construction Ltd | Construction | 2025 |
| LJK Plumbing & Heating Ltd | Construction | 2018 |
| LKR Farms Limited | Agriculture & fishing | 1997 |
| LLO Ltd | Information & communication | 2017 |
| Lloyd Harrison Developments Ltd | Real estate | 2025 |
| LMD Pubs Limited | Hospitality | 2026 |
| LMS Pro-Group Holdings Limited | Financial services | 2026 |
| Lmspr Ltd | Professional & scientific | 2025 |
| Lock Construction Ltd | Construction | 2017 |
| Locks Lane Management Company Limited | Households | 1976 |
| Locktech London Ltd | Administrative & support | 2020 |
| Loco Clothing and Lifestyle Boutique Ltd | Wholesale & retail | 2018 |
| Lodmoor Property Management Co. Limited | Households | 1980 |
| LOG Networks Limited | Information & communication | 1995 |
| Logavcon Limited | Other services | 2012 |
| Logrings Limited | Information & communication | 2011 |
| Lomand Homes Limited | Construction | 1998 |
| Long Bros (Oakdale) | Administrative & support | 1961 |
| Long Lane Dorset Ltd | Hospitality | 2024 |
| Long Street Management Limited | Households | 2017 |
| Longshore Developments Ltd | Real estate | 2013 |
| Longton Services Limited | Professional & scientific | 2006 |
| Loop Construction Technology Limited | Wholesale & retail | 2025 |
| Loop Technology Limited | Manufacturing | 1998 |
| Loose in a Chazza Shop Limited | Wholesale & retail | 2026 |
| Lore Consultancy Limited | Administrative & support | 2003 |
| Lotus Petal Healthcare Ltd | Health & social care | 2026 |
| Louis Knight Electrical Limited | Construction | 2013 |
| Love Cake Cafe Limited | Hospitality | 2016 |
| Love Homes (Dorset) Limited | Extraterritorial | 2014 |
| Loving by Nature CIC | Wholesale & retail | 2025 |
| Loving String. Limited | Manufacturing | 2024 |
| Lower Almer Farm Limited | Agriculture & fishing | 1963 |
| Lower Dairy Compton Valence Management Company Limited | Households | 1992 |
| Lower Hillside Road Management Co. Limited | Households | 1979 |
| Lower Skippet Farm Limited | Agriculture & fishing | 1973 |
| Lowran Construction Ltd | Construction | 2024 |
| Ltagritechengineering Ltd | Manufacturing | 2025 |
| Lucas Allen Limited | Real estate | 2026 |
| Lucca (Poundbury) Limited | Real estate | 2011 |
| Luccios Ltd | Hospitality | 2020 |
| Lucia Larosa Ltd | Real estate | 2016 |
| Lucy’S Commercial Cleaning Services Ltd | Other services | 2023 |
| Lufton Commercial Property Ltd | Real estate | 2026 |
| Lufton Commercials Limited | Extraterritorial | 2009 |
| Lufton Park Estates Limited | Extraterritorial | 2009 |
| Lulworth Trustees (Dorchester) Ltd | Administrative & support | 2011 |
| Lumiere Medical Limited | Health & social care | 2025 |
| Lumina Shutters & Blinds Ltd | Construction | 2026 |
| Luxury Dordogne Villas Limited | Hospitality | 2016 |
| LVG NO.1 LLP | | 2018 |
| LVW Productions Limited | Information & communication | 2024 |
| LW & KJ Martin Limited | Construction | 2011 |
| LW Business Management Limited | Professional & scientific | 2009 |
| Lyons Construction SW Ltd | Construction | 2024 |
| Lyons Landscaping Limited | Administrative & support | 2023 |
| Lytchetts Park Management Limited | Real estate | 2016 |
| M & D GAS Services Limited | Construction | 2017 |
| M & P Bricklayers Limited | Construction | 2018 |
| M & T Hull Limited | Construction | 2003 |
| M Bush Brickworks Limited | Construction | 2015 |
| M Chandler Limited | Administrative & support | 2025 |
| M D Gardner Plastering Services Limited | Construction | 2002 |
| M E Rose Ltd | Professional & scientific | 2020 |
| M J Scott Limited | Construction | 2002 |
| M S G H Services Ltd | Construction | 2014 |
| M Schack Engel Ltd | Wholesale & retail | 2025 |
| M TEK Limited | Professional & scientific | 1989 |
| M Walker Building Services Ltd | Construction | 2025 |
| M&M Pro Build & Maintain Ltd | Construction | 2020 |
| M. J. FRY Agricultural Engineering Limited | Administrative & support | 2008 |
| M.A.Tory Limited | Agriculture & fishing | 1956 |
| M.B Financial Consultancy Limited | Financial services | 2007 |
| M.B.Energy Management Limited | Administrative & support | 2004 |
| M.Christopher Buildings & Ground Maintenance Limited | Construction | 2018 |
| M.J.P. Companies Ltd | Education | 2024 |
| M.J.Pengelly Limited | Agriculture & fishing | 1954 |
| M95 Kitchen Limited | Hospitality | 2025 |
| MA8GAMING Ltd | Information & communication | 2025 |
| Mabey's Surfacing Ltd | Construction | 2024 |
| Macaulay Architectural Design Ltd | Professional & scientific | 2023 |