| Jakub's Properties UK Limited | Real estate | 2025 |
| Jamaica Lane Healthcare CIC | Health & social care | 2026 |
| James Murray Builders Limited | Construction | 2019 |
| Jameslangretail Ltd | Wholesale & retail | 2025 |
| Jammy Music Publishers Limited | Information & communication | 1977 |
| Janet Stewart Ltd | Health & social care | 2019 |
| Jaroscope Ltd | Financial services | 2011 |
| JCM Project Management Ltd | Construction | 2021 |
| Jewell Properties Greenock Ltd | Households | 2025 |
| JG Hotels Limited | Hospitality | 2025 |
| JG Prestige Property Ltd | Construction | 2024 |
| Jimelt Limited | Other services | 2025 |
| Jj&M Properties Limited | Real estate | 2024 |
| JJM Media Ltd | Professional & scientific | 2024 |
| Jk.Eng.Support Limited | Professional & scientific | 2018 |
| JM Aesthetics and Health Ltd | Health & social care | 2025 |
| JM Business Analysis Ltd | Professional & scientific | 2020 |
| JM Dwellings Ltd | Real estate | 2021 |
| JM Joinery Services Ltd | Construction | 2016 |
| JMS Process Solutions Limited | Other services | 2022 |
| Johar Clothing Limited | Wholesale & retail | 2021 |
| John F. Martin (Glasgow) Limited | Construction | 1978 |
| John Mcmenamin Plastering Services Limited | Other services | 2019 |
| John Mitchell of Greenock Limited | | 1942 |
| John Winning MCK Locum Services Limited | Health & social care | 2023 |
| Joose Juice Ltd | Manufacturing | 2013 |
| JP Hendry Ltd | Real estate | 2024 |
| JR Options Limited | Other services | 2022 |
| JSD Superstore Ltd | Wholesale & retail | 2018 |
| Juan Reyes Ltd | Arts & recreation | 2025 |
| Jumaks Ltd | Manufacturing | 2025 |
| Just Delivery Drivers Limited | Transport & logistics | 2025 |
| Just Fabulous Ltd | Professional & scientific | 2021 |
| Just Recruit Inverclyde Limited | Administrative & support | 2025 |
| JW (Greenock) Ltd | Administrative & support | 2023 |
| JZTR13CHOW Ltd. | Hospitality | 2021 |
| K & B Properties (Greenock) Ltd | Real estate | 2023 |
| K&M Fabrication Scotland Ltd | Construction | 2025 |
| Kali Aesthetics Limited | Other services | 2023 |
| Kate Dalrymple Limited | Wholesale & retail | 2025 |
| Kate Emmerson Retreats Ltd | Professional & scientific | 2022 |
| Kate Stewart Limited | Wholesale & retail | 2012 |
| Kazmi Grillz Limited | Hospitality | 2025 |
| KB Label Ltd | Professional & scientific | 2024 |
| Kehlani Group Ltd | Professional & scientific | 2024 |
| Kehlani SCO 001 Ltd | Wholesale & retail | 2024 |
| Kehlani SCO 002 Ltd | Wholesale & retail | 2024 |
| Kehlani SCO 003 Ltd | Wholesale & retail | 2024 |
| Kelpie Films Limited | Information & communication | 2000 |
| Kerr Design Services Limited | Other services | 2007 |
| Kerri Stinson Fitness Ltd | Arts & recreation | 2025 |
| Kerrybury's Limited | Manufacturing | 2022 |
| Kewdale Investments Limited | Real estate | 2021 |
| KG Diving Services Limited | Other services | 2012 |
| Kilglen Property Management Limited | Households | 2021 |
| Kilpatrick Blane Services Limited | Construction | 2010 |
| Kilted KIN Limited | Wholesale & retail | 2017 |
| Kincaid Property Investments Ltd | Real estate | 2025 |
| Kincaid Property Maintenance Ltd | Construction | 2025 |
| KIP Marketing Solutions Limited | Professional & scientific | 2018 |
| KJ Tyres Ltd | Wholesale & retail | 2022 |
| Klink Klink Limited | Hospitality | 2012 |
| Klyde K9 Friends Ltd | Agriculture & fishing | 2022 |
| KMC Heating and GAS Services Ltd | Construction | 2024 |
| KOO FM Cleaning Services Ltd | Administrative & support | 2025 |
| Kurek Building Services Ltd | Construction | 2019 |
| Kuta Ltd | Information & communication | 2026 |
| KW Brickwork Ltd | Construction | 2025 |
| Kwik Maintenance Ltd | Construction | 2023 |
| L.P.M Joinery Limited | Construction | 2025 |
| L.Pyper Superstore Ltd | Wholesale & retail | 2019 |
| LAL & RAJ 2 in 1 Ltd | Hospitality | 2018 |
| Lalley's Group Ltd | Wholesale & retail | 2020 |
| Lalleys SCO 001 Limited | Wholesale & retail | 2022 |
| Lalleys SCO 002 Limited | Wholesale & retail | 2022 |
| Lalleys SCO 003 Limited | Wholesale & retail | 2022 |
| Lalleys SCO 004 Limited | Wholesale & retail | 2022 |
| Lalleys SCO 005 Limited | Wholesale & retail | 2022 |
| Lalm Consulting Limited | Construction | 2024 |
| Lambs Coaches (Scotland) Ltd | Transport & logistics | 2026 |
| Lapwine Limited | Administrative & support | 1996 |
| Larch and Stone Limited | Construction | 2025 |
| Larry's Services Limited | Construction | 2015 |
| Larsgaard Games Limited | Information & communication | 2026 |
| Lazo Barber Ltd | Other services | 2025 |
| Ledgends Limited | Wholesale & retail | 2009 |
| Letslet.Me.Uk Limited | Real estate | 2005 |
| Leven Generation Limited | Energy | 2017 |
| Lewis Learning Ltd | Information & communication | 2008 |
| Lewis White Media Limited | Professional & scientific | 2022 |
| Lexicon Concept Limited | Construction | 2024 |
| Lexy Homes Ltd | Wholesale & retail | 2025 |
| Liam Martin's GAS Services Limited | Wholesale & retail | 2023 |
| Liberty Lifestyle Rewards Limited | Professional & scientific | 2019 |
| Lighthouse Bar (Greenock) Limited | Hospitality | 2011 |
| Lionz Ltd | Professional & scientific | 2024 |
| Little Genius Limited | Education | 2014 |
| Little Paws (Scotland) Ltd | Other services | 2023 |
| Livingstone Trade Point Ltd | Hospitality | 2026 |
| LL Marketing (Media) Limited | Professional & scientific | 2023 |