| Mouse Valley Developments Limited | Construction | 2016 |
| Mouse Valley Plant Hire Ltd | Administrative & support | 2023 |
| Mouse Valley Plant Limited | Administrative & support | 1999 |
| Mouse Valley Training Ltd | Education | 2023 |
| MT Trails Limited | Agriculture & fishing | 2025 |
| MT577 Ltd | Transport & logistics | 2024 |
| Muirkirk Motor Services Ltd | Wholesale & retail | 2024 |
| Muirs Travel Limited | Professional & scientific | 1996 |
| Munch That Lanark Ltd | Hospitality | 2024 |
| Munro Trustees Limited | Professional & scientific | 1994 |
| Muscle Injury Clinic Ltd | Other services | 2018 |
| MV Group(Scotland) Ltd | Financial services | 2025 |
| MV Plant Sales Ltd | Construction | 2023 |
| MWF Joinery Limited | Construction | 2024 |
| MWL Foods Ltd | Hospitality | 2025 |
| Myamazinghome Limited | Construction | 2024 |
| Myers-Hughes Services Ltd | Professional & scientific | 2018 |
| Myorel Ltd | Construction | 2026 |
| Myrlex Limited | Construction | 1998 |
| Nairn Joiners & Fire Protection Ltd | Construction | 2025 |
| Nanci Creedon Holdings Ltd | Financial services | 2024 |
| Nathan Software Solutions Ltd | Information & communication | 2022 |
| Naz's Enterprise Ltd | Other services | 2019 |
| Neilian Homes Limited | Construction | 2026 |
| Nessa Direct Limited | Transport & logistics | 2014 |
| Nethan Energy Limited | Energy | 2020 |
| Nethan Valley Timber Frame Homes Limited | Real estate | 2002 |
| Netherburn West (Holdings) Limited | Professional & scientific | 2017 |
| Netherburn West Limited | Energy | 2016 |
| Netherton House Limited | Administrative & support | 2025 |
| Neuron Connections Training Ltd | Professional & scientific | 2016 |
| Neuvoa Project Consult Ltd | Professional & scientific | 2019 |
| New Jholpai Limited | Hospitality | 2019 |
| New Lanark Homes Limited | Administrative & support | 2008 |
| New Lanark Trading Ltd. | Administrative & support | 1970 |
| New Manor Developments (Scotland) Ltd | Construction | 2025 |
| Newbigging Developments Ltd | Agriculture & fishing | 2022 |
| Newhouse Workwear Limited | Wholesale & retail | 2017 |
| Newmill Fishing Limited | Agriculture & fishing | 2007 |
| Nicoll Holdings Ltd | Real estate | 2020 |
| Nightjar (Lanark) Ltd | Hospitality | 2023 |
| Nimmo Properties Limited | Real estate | 2012 |
| NK Storage Ltd | Transport & logistics | 2018 |
| NMW (Scotland) Limited | Health & social care | 2025 |
| NND Catering Ltd | Hospitality | 2024 |
| No-One Dies Alone Lanarkshire CIC | Health & social care | 2024 |
| Noah's Treats (Events) Limited | Hospitality | 2021 |
| Noel Corporation Ltd | Wholesale & retail | 2025 |
| North Commercial Finance Limited | Financial services | 2020 |
| Northmanse Limited | Information & communication | 2006 |
| Novara (EU) LP | | 2015 |
| Ns&T Property Investments Limited | Real estate | 2025 |
| NS4 Productions Ltd | Information & communication | 2021 |
| O'Neill Consulting Limited | Information & communication | 1997 |
| Oakover Developments Ltd | Construction | 2023 |
| Oaktree Construction (Scotland) Ltd | Construction | 2024 |
| Oakwood Equity Ltd | Real estate | 2026 |
| Ofcn Ltd | Administrative & support | 2025 |
| Office Supplies Scotland Ltd | Wholesale & retail | 2015 |
| Old Bridgend Holiday Retreat Ltd | Hospitality | 2022 |
| Old Oak Campers Ltd | Manufacturing | 2022 |
| Olium Financial Management Ltd | Financial services | 2020 |
| ON Site Contracts Ltd | Construction | 2019 |
| Online Medicines Limited | Wholesale & retail | 2022 |
| Openborder Genetics Limited | Administrative & support | 2015 |
| Optical One Limited | Health & social care | 2000 |
| Optical Two Limited | Health & social care | 2019 |
| Optimo Hair Ltd | Other services | 2020 |
| Opus Lanark Limited | Construction | 2015 |
| Orion Property Solutions Ltd | Real estate | 2016 |
| ORR Consulting Limited | Information & communication | 2011 |
| Orrlay Marketing and Media Limited | Professional & scientific | 2025 |
| OTR Rural Ltd | Administrative & support | 2025 |
| Ovenbird Coffee Roasters Ltd | Manufacturing | 2014 |
| Oyster Homes Whitelees Limited | Construction | 2015 |
| P. B. Agri Services Ltd | Manufacturing | 2012 |
| Palba Ltd | Wholesale & retail | 2019 |
| Paradventures | Other services | 2014 |
| Paradventures Support Limited | Other services | 2014 |
| PARCEL2SEND Ltd | Transport & logistics | 2026 |
| Parishholm Farm | | 1996 |
| Partnership Matters Consulting Limited | Professional & scientific | 2016 |
| Paterson Renewable Energy Limited | Construction | 2026 |
| Peace Lily Retreats Ltd | Arts & recreation | 2020 |
| Peach Boutique Ltd | Other services | 2025 |
| Pearl Cleaning & Gardening Ltd | Administrative & support | 2018 |
| Peggy White's Limited | Wholesale & retail | 2004 |
| Pelvic and Core Physiotherapy Ltd | Other services | 2024 |
| Pepe’S Group Ltd | Hospitality | 2025 |
| Perfect Edge Plastering Ltd | Construction | 2022 |
| Person of Interests Ltd | Information & communication | 2021 |
| Phomer Ltd | Information & communication | 2025 |
| Physicare Limited | Health & social care | 1996 |
| Pickled Haggis Limited | Hospitality | 2020 |
| Pine Valley Homes (Hyndford) Limited | Construction | 2023 |
| Pint of Lanark Ltd | Real estate | 2025 |
| PJA Music Management Limited | Administrative & support | 2002 |
| Plant Fitter (UK) Ltd | Manufacturing | 2023 |
| Platform 9 Properties Ltd | Real estate | 2025 |
| Platinum Key Property Ltd | Real estate | 2025 |