| Mechtronic Scotland Ltd | Wholesale & retail | 2026 |
| Medalliance Ltd | Professional & scientific | 2016 |
| Medamet Ltd | Health & social care | 2025 |
| Medical Innovation Systems Ltd | Information & communication | 2019 |
| Mega Grocers Ltd | Wholesale & retail | 2024 |
| Meldon Networking Ltd | Professional & scientific | 2023 |
| Mell Mechanical Engineering Ltd | Professional & scientific | 2023 |
| Menzies Developments Ltd | Professional & scientific | 2019 |
| Mercury Real Estate Limited | Real estate | 2003 |
| Merkland Design & Engineering Consultancy Limited | Professional & scientific | 2015 |
| Merlin Business Services Limited | Professional & scientific | 2001 |
| Mernoc Limited | Information & communication | 2011 |
| Merriton Limited | Manufacturing | 2018 |
| Merryhagen Farming Ltd | Agriculture & fishing | 2023 |
| Mesi Studios Limited | Administrative & support | 2013 |
| Mesmer-Eyez T/A GLO Ltd | Other services | 2023 |
| MF Contracts Ayrshire Ltd | Construction | 2020 |
| MFP Building Contracts Ltd | Construction | 2022 |
| MHC Properties Group Ltd | Real estate | 2025 |
| MHC Traffic Ltd | Professional & scientific | 2006 |
| MI Global Store Limited | Wholesale & retail | 2026 |
| Michael J Woods Limited | Construction | 2014 |
| Micktech Ltd | Information & communication | 2017 |
| Microtech Business Intelligence Limited | Real estate | 2014 |
| Microtech Digital Limited | Information & communication | 2014 |
| Microtech ENS Limited | Information & communication | 2017 |
| Microtech Group Limited | Financial services | 2010 |
| Microtech Support Limited | Information & communication | 2003 |
| Microtech Trustees Limited | Professional & scientific | 2021 |
| Mikeylenn Ltd | Hospitality | 2019 |
| Millar Blinds Contracts Ltd | Manufacturing | 2026 |
| Miller Cafes Limited | Hospitality | 2020 |
| Miller Leisure (Ayrshire) Limited | Arts & recreation | 2011 |
| Miller Property Developments Limited | Construction | 2004 |
| Milligan Electrical Limited | Construction | 1996 |
| Milne Property Solutions Limited | Construction | 2024 |
| Mind Matters Ltd | Education | 2025 |
| Mind Positive Live Learning & Events Limited | Health & social care | 2024 |
| Mind Positive Scotland Limited | Health & social care | 2020 |
| Mind, Body & Spirit Events Ltd | Administrative & support | 2024 |
| Minto Drilling Limited | Professional & scientific | 2021 |
| Mipatient Ltd | Information & communication | 2020 |
| Mirza Convenience Stores Ltd. | Wholesale & retail | 2011 |
| MJ Properties Group Ltd | Real estate | 2026 |
| MJM147 Ltd | Hospitality | 2025 |
| MJR Epoxy Ltd | Construction | 2025 |
| MJR Group Solutions Ltd | Construction | 2017 |
| MK Kitchens and Joinery Limited | Construction | 2020 |
| Mkkk 2 Limited | Financial services | 2024 |
| Mkkk Limited | Financial services | 2019 |
| MKN Enterprises Limited | Wholesale & retail | 2018 |
| MKN Plumbing & Heating Engineers Limited | Construction | 2019 |
| ML Ayrshire Electrical Limited | Construction | 2021 |
| MLT Digital Limited | Information & communication | 2006 |
| MM Media Productions Ltd | Administrative & support | 2022 |
| MM Roofing Building and Landscapes Ltd | Construction | 2024 |
| MMH Management Limited | Professional & scientific | 2020 |
| Mmmb Ltd | Financial services | 2016 |
| Mo's Plaice Ltd | Hospitality | 2024 |
| Mobile Podiatry Care Limited | Health & social care | 2025 |
| Mobility Matters Limited | Manufacturing | 2016 |
| Mobility Matters Retail Ltd | Wholesale & retail | 2025 |
| MOC (Scotland) Limited | Hospitality | 2004 |
| Modcon Rollatray Limited | Construction | 2017 |
| Modulaspace Limited | Manufacturing | 2021 |
| Modway Limited | Construction | 2011 |
| Moir and Sweeney LLP | | 2021 |
| Mollie's Laundry Services Ltd | Other services | 2021 |
| Monarch Commercial Properties Ltd | Real estate | 2022 |
| Monarch Financial Services Ltd | Professional & scientific | 2016 |
| Moneyacres Transport Ltd. | Transport & logistics | 2007 |
| Monkey Films Limited | Information & communication | 2001 |
| Montgomery Land Limited | Agriculture & fishing | 2021 |
| Montgomery Scotia International Ltd | Other services | 2019 |
| Moog Holdings Limited | Real estate | 2023 |
| Moogal Contracts Ltd | Construction | 2018 |
| Mookers Ltd | Administrative & support | 2017 |
| More Than Just a Handyman Ltd | Administrative & support | 2021 |
| Morel Property Ltd | Real estate | 2018 |
| Morris Anaesthesia Services | | 1996 |
| Mosanny Home Care Limited | Health & social care | 2023 |
| Motion Property Services Ltd | Real estate | 2020 |
| Mountain Spice Ltd | Hospitality | 2023 |
| Mountfield Developments Limited | Construction | 2007 |
| Move Better Kilmarnock Ltd | Health & social care | 2024 |
| Moveauto Limited | Other services | 1988 |
| MPL Enterprises Ltd | Real estate | 2025 |
| Mpyo Consultancy Limited | Professional & scientific | 2019 |
| MR Jobby's Cleaning Services Ltd | Administrative & support | 2025 |
| MR Technical Services (Scotland) Ltd. | Construction | 2014 |
| MR Webster Film Ltd | Information & communication | 2018 |
| MS Amin Ltd | Wholesale & retail | 2025 |
| MS Energy Group Limited | Professional & scientific | 2026 |
| MSC Kitchens & Bathrooms Ltd | Construction | 2023 |
| MSL Property Services Ltd | Real estate | 2025 |
| Mspy Ltd | Wholesale & retail | 2024 |
| MTM Exterior Home Projects Ltd | Construction | 2017 |
| Muazzen Limited | Health & social care | 2023 |
| Muirend Farming Company Limited | Agriculture & fishing | 1959 |
| Muirhead Plant Limited | Construction | 2003 |