| Kernow Plumbing & Heating Ltd | Construction | 2021 |
| Kernow Professional Cleaning Ltd | Administrative & support | 2026 |
| Kernow Security Services Limited | Administrative & support | 2019 |
| Kernow Surgeons Limited | Transport & logistics | 2016 |
| Kernow Surgical LLP | | 2016 |
| Kernow Together CIC | Education | 2026 |
| KERNOW4PAWS Ltd | Wholesale & retail | 2025 |
| Kestevyn Limited | Construction | 2021 |
| Kickappz Limited | Professional & scientific | 2005 |
| Kidskidneys Ltd | Health & social care | 2014 |
| Kimberley House (Penzance) Management Co. Ltd | Hospitality | 2008 |
| Kingswood Construction Services Limited | Real estate | 1991 |
| Kirby Granite Sales Limited | Construction | 2005 |
| Kiri.Surf Ltd | Manufacturing | 2021 |
| Kirsty's Kitchen Cornwall CIC | Manufacturing | 2025 |
| Kittens in Timespace Ltd | Information & communication | 2019 |
| Kliskey Independent Financial Services Limited | Financial services | 2003 |
| Knifeman Limited | Wholesale & retail | 2017 |
| Kreef Limited | Health & social care | 2019 |
| Kristin C Simmons Limited | Professional & scientific | 2014 |
| KRS Cornwall Limited | Wholesale & retail | 2025 |
| Ksmgmt Ltd | Professional & scientific | 2023 |
| Ktmp Developments Ltd | Construction | 2020 |
| Kurt & Caroline Jackson Limited | Arts & recreation | 2005 |
| Kwiv Limited | Hospitality | 2024 |
| L Happy Palace Limited | Hospitality | 2016 |
| Lafrowda Logs Ltd | Wholesale & retail | 2023 |
| Lafrowda Villas Ltd | Real estate | 2020 |
| Laity Agricultural Ltd | Agriculture & fishing | 2026 |
| Laity Plant & Groundworks Limited | Construction | 2015 |
| Lamorna Group Limited | Financial services | 2023 |
| Lamp & Whistle Ltd | Hospitality | 2015 |
| Land Productions Ltd | Information & communication | 2025 |
| Lands END Camping and Glamping Ltd | Hospitality | 2019 |
| Lands END Peninsula CLT Limited | Other services | 2010 |
| Lanhydrock Sporting Club Limited | Arts & recreation | 2026 |
| Lanisley Ltd | Construction | 2018 |
| Lay's Auctioneers Limited | Wholesale & retail | 2019 |
| Lean Excellence Limited | Professional & scientific | 2009 |
| LEE Orthopaedic Surgical Services Limited | Financial services | 2014 |
| Leighton Ballett Advertising Consultant Limited | Professional & scientific | 2020 |
| Lena Gillan Ltd | Manufacturing | 2024 |
| Lerto Limited | Hospitality | 2021 |
| Leskinnick Warehouse Management Company Limited | Real estate | 2008 |
| Leswidden Common Fuel Depot Limited | Wholesale & retail | 1986 |
| Lewis I C Trading Ltd | Wholesale & retail | 2025 |
| Liam Nichol Carpentry Ltd | Construction | 2023 |
| Liberty House Management Services Limited | Real estate | 2017 |
| Liberty Skincare & Aesthetics Limited | Other services | 2012 |
| Lifeblood Consultancy Limited | Professional & scientific | 2019 |
| Lifton Estates Limited | Financial services | 2024 |
| Lilly FEE Wood Carving Studio Ltd | Manufacturing | 2007 |
| Lime London Limited | Real estate | 2006 |
| Limitless Waste Ltd | Wholesale & retail | 2021 |
| Lionstag Ventures Limited | Hospitality | 2020 |
| Little Blossoms ST Just Ltd | Wholesale & retail | 2013 |
| Little Dowran Farm Limited | Agriculture & fishing | 2021 |
| Little Explorers PZ Ltd | Education | 2025 |
| Little Green Seaweed Ltd | Agriculture & fishing | 2023 |
| Littoral/Projects Environment | Arts & recreation | 1990 |
| Livetrace Ltd | Wholesale & retail | 2012 |
| Llamarama Limited | Wholesale & retail | 2008 |
| Lodge & Hicks Ltd | Professional & scientific | 2012 |
| Logan Cleaning Services Ltd | Administrative & support | 2025 |
| Long Rock Holdings Limited | Financial services | 2023 |
| Long Rock Laundry & Linen Hire Limited | Other services | 2021 |
| Longrock Enterprises Limited | Real estate | 2009 |
| Lowen Trevow Ltd | Real estate | 2021 |
| Lowena Property Developments Limited | Real estate | 2014 |
| Lowenmor Limited | Agriculture & fishing | 2002 |
| LT Painters Ltd | Manufacturing | 2024 |
| Luca Residential Ltd | Real estate | 2023 |
| Ludgvan Community Childcare Centre Limited | Education | 1996 |
| Lulla Lettings Ltd | Real estate | 2023 |
| Luxury Nail & Spa Ltd | Other services | 2024 |
| Lyonesse Air Transport Limited | Transport & logistics | 2004 |
| Lyonesse Shipping Company 1 Limited | Transport & logistics | 2023 |
| Lyonesse Shipping Company 2 Limited | Transport & logistics | 2023 |
| Lyonesse Shipping Company 3 Limited | Transport & logistics | 2023 |
| Lyonesse Shipping Company Limited | Transport & logistics | 2004 |
| M J Marine Group Ltd | Manufacturing | 2011 |
| M L Truman Chiropodists Ltd | Health & social care | 2025 |
| M R Technical Limited | Construction | 2007 |
| M. J. Marine Charters Limited | Transport & logistics | 2010 |
| M. J. Marine Electronics Limited | Wholesale & retail | 2010 |
| M.4.ME Ltd | Wholesale & retail | 2026 |
| Macdonald Wing Radiology Limited | Health & social care | 2021 |
| Madd Motors Limited | Wholesale & retail | 2026 |
| Madjester Limited | Wholesale & retail | 2004 |
| Maen Publishing Limited | Information & communication | 2017 |
| Magic Pelagic Fishing Limited | Agriculture & fishing | 2011 |
| MAISON191. Limited | Professional & scientific | 2023 |
| Makai Watersports Ltd | Administrative & support | 2005 |
| Make Stores Ltd | Wholesale & retail | 2014 |
| Maleah BEA Okalani Malley Ltd | Extraterritorial | 2021 |
| Mana Sport Ltd | Manufacturing | 2023 |
| Manakamana Limited | Hospitality | 2021 |
| Manhattan Style Academy Limited | Wholesale & retail | 1989 |
| Maracaibo Coffee Limited | Wholesale & retail | 2025 |
| Marigold Ventures Limited | Hospitality | 2002 |