| J Mckenzie Ltd | Manufacturing | 2023 |
| J.C. Roxburgh (Investments) Limited | Real estate | 1962 |
| J.L.Cars Ltd | Administrative & support | 2014 |
| JB Builders & Joiners Ltd | Construction | 2026 |
| JBW Limited | Real estate | 2025 |
| Jcolquhoun IT Business Services Ltd. | Information & communication | 2007 |
| JDW Electrical Services Ltd | Construction | 2017 |
| Jenna Ferguson Art Ltd | Wholesale & retail | 2026 |
| Jensyn Motor Company Limited | Wholesale & retail | 2010 |
| JH Power Services Limited | Professional & scientific | 2024 |
| JLC Exotic Security Services Ltd | Administrative & support | 2026 |
| JLC Venue Services Limited | Administrative & support | 2022 |
| Jlctyres Ltd | Wholesale & retail | 2025 |
| JM GOW Electrical Limited | Construction | 2017 |
| JM Grounds Works Ltd. | Construction | 2014 |
| Jmmp Properties Ltd | Real estate | 2021 |
| Jmtechsolutions Limited | Other services | 2019 |
| Jock Rock (Entertainments) Limited | Arts & recreation | 1988 |
| John B Ecommerce Limited | Wholesale & retail | 2025 |
| John H. Glen & SON Limited | Other services | 1987 |
| John Martin & SON Contractors Ltd | Administrative & support | 2006 |
| John Talbot Consultancy Ltd | Professional & scientific | 2018 |
| Joinery Needs Ltd | Construction | 2025 |
| JT Design Limited | Professional & scientific | 2009 |
| KAF Locum Services Limited | Health & social care | 2024 |
| Kane Design Solutions Ltd | Professional & scientific | 2022 |
| Kara Barbers Ltd | Other services | 2025 |
| Kara KQ Limited | Other services | 2025 |
| Karsten Global Partners Limited | Administrative & support | 2025 |
| KG Design & Installation Ltd | Construction | 2011 |
| KG GAS Ltd | Construction | 2024 |
| KG Installation and Design Ltd | Construction | 2016 |
| Khaira Licensed Grocers Ltd | Wholesale & retail | 2022 |
| Kiaora Properties Ltd | Real estate | 2019 |
| Kilmaronock Millennium Association | Other services | 1998 |
| Kilmaronock Stud Unlimited | Agriculture & fishing | 2021 |
| Kinetic Civil Engineering Ltd | Construction | 2021 |
| Klroofing&Roughcasting Ltd | Construction | 2021 |
| KSA Contracts Ltd | Construction | 2023 |
| Kwick Kleen Domestics Limited | Administrative & support | 2024 |
| KYL Digital Ltd | Information & communication | 2020 |
| KYL Investments Limited | Real estate | 2025 |
| Labrakita Marketing Limited | Professional & scientific | 2021 |
| Lb&E Ltd | Other services | 2024 |
| LCS Controls Ltd | Professional & scientific | 2022 |
| Ledgerwood Electrical Ltd | Manufacturing | 2018 |
| Leven Tavern Limited | Wholesale & retail | 2023 |
| Leven Valley Joinery Ltd | Construction | 2025 |
| Levenside Properties Ltd | Households | 2025 |
| Lightsim Limited | Professional & scientific | 2016 |
| Live Well Home Help & Independent Living Support Limited | Health & social care | 2025 |
| LJ Black Grounds Maintenance Ltd | Administrative & support | 2019 |
| Llwe Limited | Wholesale & retail | 2019 |
| Loch Lomond Cars Limited | Transport & logistics | 2018 |
| Loch Lomond Golf Club Limited | Arts & recreation | 2009 |
| Loch Lomond Highland Games Limited | Arts & recreation | 1998 |
| Loch Lomond Investments Ltd | Professional & scientific | 2023 |
| Loch Lomond News Limited | Wholesale & retail | 2004 |
| Loch Swim Alba Ltd | Arts & recreation | 2020 |
| Lochlomondconsulting.Com Limited | Construction | 2021 |
| Lochs & Glens (Hotels) Holdings Limited | Hospitality | 2026 |
| Lochs & Glens (Transport) Holdings Limited | Transport & logistics | 2026 |
| Lochs and Glens (Transport) Limited | Transport & logistics | 1995 |
| Lochside Natural Products Limited | Wholesale & retail | 2016 |
| Lochside Sauna Limited | Other services | 2024 |
| Lomond Accountants Ltd | Professional & scientific | 2019 |
| Lomond Auto Centre Ltd. | Wholesale & retail | 2004 |
| Lomond BMG Ltd | Hospitality | 2010 |
| Lomond Car & Van Centre Ltd | Wholesale & retail | 2026 |
| Lomond Car Centre Ltd. | Wholesale & retail | 1996 |
| Lomond Courtyard Balloch Holiday Lettings Ltd | Hospitality | 2023 |
| Lomond Data Solutions Ltd | Information & communication | 2024 |
| Lomond Eventures Ltd | Hospitality | 2023 |
| Lomond Fish Bar Ltd | Hospitality | 2012 |
| Lomond Gateway Holiday Lettings Balloch Ltd | Hospitality | 2022 |
| Lomond IT Services Ltd | Information & communication | 2026 |
| Lomond Lets Limited | Real estate | 2021 |
| Lomond N Loaded Ltd | Hospitality | 2025 |
| Lomond Network Solutions Limited | Information & communication | 2010 |
| Lomond Plumbing Services Ltd | Construction | 2026 |
| Lomond Property Services Ltd | Administrative & support | 2026 |
| Lomond Robotics Limited | Professional & scientific | 2024 |
| Lomond Timber Merchants Ltd | Wholesale & retail | 2019 |
| Lomondprint Limited | Manufacturing | 1986 |
| LRJ Construction Ltd | Construction | 2018 |
| LS & AW Investments Ltd | Real estate | 2025 |
| Lumi Cafe Limited | Hospitality | 2025 |
| Luss and Arden Community Development Trust | Other services | 2004 |
| Luss Estates Company | Agriculture & fishing | 1961 |
| Luss Trading Company | Wholesale & retail | 2025 |
| Luss Village Shop Ltd | Wholesale & retail | 2013 |
| Luxe Body Edit Limited | Other services | 2026 |
| M F Wells (Hotels) Limited | Administrative & support | 1984 |
| Macleod Contracts Ltd | Other services | 2019 |
| Make Interactive Ltd | Information & communication | 2015 |
| Malpaso Property Limited | Real estate | 2016 |
| Mardella Cottage Limited | Hospitality | 2026 |
| Marine Clean (Scotland) Ltd | Other services | 2018 |
| Marine Sales (Loch Lomond) Limited | Wholesale & retail | 2022 |
| Marine Sales Scotland Limited | Wholesale & retail | 2022 |