| Longcliffe Quarries Limited | Mining & quarrying | 1933 |
| Longcliffe Quarrying Company Limited | Extraterritorial | 1984 |
| Lorash Limited | Real estate | 2025 |
| LRD Automotive Limited | Wholesale & retail | 2023 |
| LRK Consulting Group Limited | Professional & scientific | 2020 |
| LTM Compliance (Matlock) Limited | Financial services | 2013 |
| Lukejefford.Com Ltd. | Professional & scientific | 2012 |
| Luks Car Sales Garage Limited | Wholesale & retail | 2019 |
| Lumsdale Model Club Limited | Professional & scientific | 2017 |
| Lumsdale Surveyors Ltd | Professional & scientific | 2023 |
| Luxury Loos and Event Hire Limited | Other services | 2017 |
| Lydia Hair & Co Ltd | Other services | 2026 |
| Lykke Tribe Limited | Arts & recreation | 2019 |
| Lyshaw Limited | Arts & recreation | 2023 |
| M and S Electrical Installations Limited | Construction | 2025 |
| M C Driving School Ltd | Education | 2009 |
| M K Leisure Group Ltd | Hospitality | 2024 |
| M Price Contracting Limited | Construction | 1997 |
| M Price Group Limited | Financial services | 2017 |
| M Price Services Limited | Administrative & support | 2019 |
| M Shattock Design Create Ltd | Construction | 2015 |
| M.I.A-Airsoft Ltd | Arts & recreation | 2024 |
| Maazi Limited | Hospitality | 2010 |
| Maclea Consultancy Ltd | Professional & scientific | 2025 |
| Magicglow Ltd | Wholesale & retail | 2023 |
| Major Midland Properties Ltd | Hospitality | 2005 |
| Malco Oilfield Services Ltd | Mining & quarrying | 2017 |
| Mama's Cleaning Ltd | Hospitality | 2025 |
| Mandale Stone Company Limited | Mining & quarrying | 2001 |
| Manifold Medical Communications Ltd | Professional & scientific | 2012 |
| Manning Holden Architects Limited | Professional & scientific | 2019 |
| Manor Estate Homes Ltd | Real estate | 2018 |
| Manor Farm Group Limited | Real estate | 2015 |
| Mariposa Care Group Limited | Health & social care | 2016 |
| Mariposa Care Homes Limited | Health & social care | 2024 |
| Mark Ward Services Ltd | Construction | 2026 |
| Markham MAY Ltd | Education | 2013 |
| Marsden Young Limited | Information & communication | 2018 |
| Marsh Green Cafe and Farm Shop Ltd | Wholesale & retail | 2023 |
| Marsh Renovations Limited | Administrative & support | 2017 |
| Marshall Catering Ltd | Hospitality | 2023 |
| Marshall Electric Ltd | Construction | 2015 |
| Mart & Sons Property Limited | Real estate | 2026 |
| Martin Seddon Limited | Professional & scientific | 2016 |
| Martin Tucker Limited | Professional & scientific | 1999 |
| Masala WOK Ltd | | 2009 |
| Masami Ltd | Public administration | 2018 |
| Match Metals Ltd | Wholesale & retail | 2020 |
| Matirix Ltd | Information & communication | 2025 |
| Matlock Angling Club Limited | Arts & recreation | 2006 |
| Matlock Ghost Emporium Ltd | Wholesale & retail | 2024 |
| Matlock Golf Club (Property) Limited | Arts & recreation | 1921 |
| Matlock Golf Club Limited | Arts & recreation | 2013 |
| Matlock Green Garage Limited | Professional & scientific | 1969 |
| Matlock Green Garage Repair Centre Limited | Wholesale & retail | 2015 |
| Matlock Kitchen & Bathroom Centre Ltd | Construction | 2008 |
| Matlock Meadows Limited | Manufacturing | 2010 |
| Matlock MOT Tyre & Exhaust Centre Limited | Wholesale & retail | 2006 |
| Matlock Nails & Spa Limited | Other services | 2025 |
| Matlock Physiotherapy Centre Limited | Other services | 2002 |
| Matlock Property Group Ltd | Extraterritorial | 2021 |
| Matlock Quick Spin Ltd | Other services | 2026 |
| Matlock Town (1878) Ltd | Arts & recreation | 2026 |
| Matlock Town F.C. Ltd | Education | 2019 |
| Matlock Town Holdings Ltd | Financial services | 2025 |
| Matlock Wines Limited | Agriculture & fishing | 2023 |
| Matlockphones Ltd | Wholesale & retail | 2023 |
| Matthew Gill Properties Limited | Manufacturing | 2006 |
| Maybridge Commercial Limited | Professional & scientific | 2004 |
| Mayfair Cheapskate Limited | Wholesale & retail | 2024 |
| MB Consultants Ltd | Information & communication | 2018 |
| MB Plumbing and Heating Engineers Limited | Professional & scientific | 2014 |
| MB Real Estate Ltd | Real estate | 2018 |
| MBS Consulting Ltd | Professional & scientific | 2023 |
| Mcdonald Concierge Ltd | Professional & scientific | 2020 |
| Mcgregor Aerospace Consultancy Ltd | Professional & scientific | 2014 |
| Mchz Limited | Hospitality | 2025 |
| Meadow Fresh Laundry Ltd | Other services | 2024 |
| Meerbrook Management Company Limited | Households | 2016 |
| Melior Communications Limited | Professional & scientific | 2020 |
| Mercan Handyman Services Limited | Construction | 2021 |
| Merebrook Consulting Limited | Professional & scientific | 1992 |
| Merris Development Engineers Limited | Manufacturing | 2002 |
| Metal Fabrication Solutions Limited | Manufacturing | 2016 |
| Metals Reclamation Technology Ltd | Manufacturing | 2003 |
| Metesford Spa Management Company Limited | Households | 2002 |
| Meticulous Maids (Matlock) Limited | Administrative & support | 2003 |
| Metriqa Ltd | Professional & scientific | 2019 |
| MFI Energy Limited | Construction | 2018 |
| Michael Fogg Funeral Directors Limited | Extraterritorial | 2025 |
| Mick Wain Consultancy Limited | Professional & scientific | 2016 |
| Microw Engineering Limited | Manufacturing | 2002 |
| Mid-Air Site Services Limited | Construction | 2004 |
| Midland & General Holdings Ltd | Financial services | 2017 |
| Midland Automotive Group Limited | Wholesale & retail | 2021 |
| Midland Chain Waxing Limited | Manufacturing | 2023 |
| Midland Corrosion Services Ltd. | Professional & scientific | 2001 |
| Midland Hotel (Matlock Bath) Limited | Hospitality | 2002 |
| MIJ Associates Limited | Health & social care | 2001 |
| Mikeneelydigital Ltd | Professional & scientific | 2022 |