| Ledgerly Bookkeeping Ltd | Professional & scientific | 2025 |
| Lemon Hill Gardens Management Company (Mylor Bridge) Limited | Households | 1995 |
| Lemon Twist 1 Ltd | Hospitality | 2023 |
| Lewis Bond (Property) Limited | Real estate | 2003 |
| LG Accountancy & Payroll Services Limited | Professional & scientific | 2011 |
| LGS UK Ltd | Construction | 2008 |
| LHR Electrical Ltd | Construction | 2025 |
| Liberated Embedded Systems Ltd | Manufacturing | 2023 |
| Liberty Hotels Ltd | Other services | 2021 |
| Lichen Limited | Real estate | 2025 |
| Life Batteries Ltd | Wholesale & retail | 2020 |
| Lifeboat Homes Limited | Construction | 2016 |
| Light UP Cornwall Limited | Hospitality | 2023 |
| Lighthouse Cornwall Ltd | Financial services | 2025 |
| Lighthouse Printing Limited | Manufacturing | 2010 |
| Lili Korawys Development Ltd | Construction | 2025 |
| Lili Korawys Management Ltd | Real estate | 2026 |
| Lillyfreya Wealth Management Limited | Financial services | 2010 |
| Lilyrose Architecture Ltd | Construction | 2022 |
| Lilywhite Living Ltd | Real estate | 2025 |
| Lily’S of Truro by Punkthai Ltd | Hospitality | 2016 |
| Linens by Mollie Ltd | Administrative & support | 2023 |
| Liquid Glass Coatings Global Ltd | Wholesale & retail | 2014 |
| Little Tree Woodland School CIC | Education | 2018 |
| Little-In-Sight Residents Ltd | Real estate | 2006 |
| Living the Dream Southwest Ltd | Health & social care | 2026 |
| Lizard Roofing Ltd | Construction | 2018 |
| Liztol Ltd | Health & social care | 2025 |
| Logan Creative Ltd | Information & communication | 2024 |
| Lohan Limited | Wholesale & retail | 2004 |
| London Musicians Limited | Other services | 1980 |
| Londondreams of 2025 Limited | Health & social care | 2025 |
| Looe Chandlery Limited | Wholesale & retail | 2010 |
| Lotus Property Services Cornwall Ltd | Real estate | 2020 |
| Louard Investments Ltd | Financial services | 2023 |
| Louellis Electrical Contractors Ltd | Construction | 2019 |
| Louise Starkey Consulting Ltd | Administrative & support | 2020 |
| Lowarth Sevi Management Limited | Households | 2020 |
| Lowen Financial Planning Ltd | Financial services | 2022 |
| Lowenna Limited | Real estate | 2025 |
| Lower Tamar Fishing Club Limited | Agriculture & fishing | 1976 |
| Lucid Machine Limited | Administrative & support | 2025 |
| Lucie Watkins Ltd | Wholesale & retail | 2025 |
| Lucky ROD Pizzas Ltd | Hospitality | 2026 |
| Lugo Rock Limited | Hospitality | 2020 |
| LUX BLU Developments Ltd | Construction | 2016 |
| LUX BLU London Ltd | Real estate | 2018 |
| LUX BLU Management Limited | Real estate | 2018 |
| Luxury Aparthotel Falmouth Ltd | Hospitality | 2024 |
| Lynfield Leasing Limited | Administrative & support | 2006 |
| Lynton Heath Limited | Professional & scientific | 2015 |
| M L B Motor Company Limited | Wholesale & retail | 2009 |
| Mabey Creative Properties Ltd | Real estate | 2016 |
| Mably Letting's Ltd | Real estate | 2026 |
| Macaulay Developments Ltd | Construction | 2021 |
| Maenporth Coastal Holidays Ltd | Administrative & support | 2017 |
| Maenporth Electrical Limited | Construction | 2005 |
| Maenporth Estate Company Limited | Households | 1993 |
| Maenporth Owners Limited | Professional & scientific | 2004 |
| Magnier Limited | Manufacturing | 2025 |
| Mailaway Limited | Professional & scientific | 2011 |
| Mainstay Construction Ltd | Construction | 2023 |
| Maintain Cornwall Ltd | Construction | 2025 |
| Mallinsons Limited | Professional & scientific | 2005 |
| Manaccanite Ltd | Hospitality | 2023 |
| Manningford Financial Services Limited | Professional & scientific | 1988 |
| Mannyai Ltd | Information & communication | 2019 |
| MAP Digital Projects Ltd | Arts & recreation | 2017 |
| MAR Studio Ltd | Professional & scientific | 2018 |
| Marchant Aviation Services Limited | Professional & scientific | 2025 |
| Marcus Reed Audio Limited | Wholesale & retail | 2015 |
| Marifield Lettings Ltd | Real estate | 2022 |
| Marine Asset Management Limited | Administrative & support | 2006 |
| Marine Associates Limited | Professional & scientific | 2011 |
| Marine Bar Limited | Hospitality | 2016 |
| Marine Coating Services Ltd | Administrative & support | 2016 |
| Marine Management Limited | Real estate | 1985 |
| Marine Minerals Limited | Mining & quarrying | 2009 |
| Marine Procurement and Consultancy Ltd | Professional & scientific | 2021 |
| Marine Trak Engineering Ltd | Manufacturing | 2022 |
| Mariners Consulting Limited | Information & communication | 2022 |
| Maritime South West Ltd | Other services | 2025 |
| Maritime SW Ltd | Other services | 2025 |
| Maritime UK South West Ltd | Other services | 2019 |
| Maritime UK SW Ltd | Other services | 2024 |
| Mark Bennett Windscreens Ltd | Wholesale & retail | 2022 |
| Mark Ripley Ltd | Information & communication | 2019 |
| Marlborough Flats (Falmouth) Limited | Hospitality | 1972 |
| Marnick Builders Limited | Construction | 2004 |
| Marnick Properties Limited | Real estate | 2020 |
| Martin Senior Support Ltd | Health & social care | 2022 |
| Maskdean Limited | Administrative & support | 2003 |
| Mattayas Ltd | Health & social care | 2025 |
| Matthews Cooper Limited | Professional & scientific | 2007 |
| Mawnan Smith Electrical Ltd | Construction | 2021 |
| Mawnan Smith Finance Limited | Financial services | 2021 |
| MAX Bagels UK Ltd | Hospitality | 2022 |
| Maxari Ltd | Wholesale & retail | 2017 |
| Mayo Electrical Limited | Construction | 2012 |
| Maywood Property Limited | Real estate | 2016 |