| Major Windows Limited | Construction | 2014 |
| MAK 85 Ltd. | Construction | 2017 |
| MAK Drywall Limited | Construction | 2023 |
| Makary Transport Ltd. | Transport & logistics | 2016 |
| Make Believe Beauty & Cosmetics Ltd | Wholesale & retail | 2014 |
| Makella Consulting Ltd | Professional & scientific | 2026 |
| Makusha CIC | Health & social care | 2023 |
| Makvi Solutions Ltd | Other services | 2022 |
| Malbon Plumbing and Heating Ltd | Construction | 2023 |
| Malibu TAN Studios Ltd | Other services | 2025 |
| Malinka Market Mansfield Ltd | Wholesale & retail | 2025 |
| Malkan Enterprises Limited | Health & social care | 2003 |
| Mall Nominee Three Limited | Construction | 2016 |
| Mallah Management Ltd | Professional & scientific | 2022 |
| Mallard Partners Limited | Professional & scientific | 2022 |
| Maloney Holdings (Notts) Limited | Professional & scientific | 2012 |
| Malraux Limited | Information & communication | 2021 |
| Malt Cottage Properties Limited | Real estate | 2000 |
| Mama Moana Ltd | Wholesale & retail | 2026 |
| Mamo Properties Ltd | Real estate | 2026 |
| Manage by Croft Limited | Professional & scientific | 2025 |
| Managed Control Solutions Ltd | Construction | 2014 |
| Managed Desktop Ltd | Information & communication | 2011 |
| Management Staff Matrix Ltd | Professional & scientific | 2025 |
| Manica Hub Ltd | Health & social care | 2018 |
| Manley Property Limited | Real estate | 2025 |
| Manley's Electrical Services Ltd | Manufacturing | 2019 |
| Manleys Properties Ltd | Construction | 2025 |
| Mann Properties Limited | Real estate | 1996 |
| Mannerock Ltd | Health & social care | 2014 |
| Manny Property Ltd | Hospitality | 2023 |
| Manole Limited | Transport & logistics | 2024 |
| Manor Astro Limited | Arts & recreation | 2024 |
| Manor Developments (Retford) Limited | Construction | 2011 |
| Manor Exteriors Limited | Construction | 2002 |
| Manor Road Management (Sewell) Limited | Households | 2023 |
| Mansell Equine Services Ltd | Other services | 2024 |
| Mansfield Aquatic, Reptile and Pet Centre Limited | Wholesale & retail | 2014 |
| Mansfield Aquatics Limited | Wholesale & retail | 2008 |
| Mansfield Asphalt Company Limited | Manufacturing | 1967 |
| Mansfield Autoworks Limited | Wholesale & retail | 2013 |
| Mansfield Bowling Club | Arts & recreation | 2006 |
| Mansfield Brick Company Limited | Manufacturing | 1964 |
| Mansfield Brix Ltd | Real estate | 2025 |
| Mansfield Building Contractors Ltd | Construction | 2021 |
| Mansfield Bulk Haulage Ltd | Transport & logistics | 2023 |
| Mansfield Cakebox Ltd | Wholesale & retail | 2025 |
| Mansfield Canine Centre Ltd | Agriculture & fishing | 2019 |
| Mansfield Carpets Ltd | Wholesale & retail | 2024 |
| Mansfield Community and Voluntary Service (CVS) | Other services | 2003 |
| Mansfield Cryogenics (EOT) Limited | Professional & scientific | 2024 |
| Mansfield Drains Ltd | Water & waste | 2023 |
| Mansfield Driveways & Patios Ltd | Construction | 2026 |
| Mansfield Eco Waste Solutions Ltd | Water & waste | 2026 |
| Mansfield Electrical Supplies Ltd | Construction | 2020 |
| Mansfield Fascias Limited | Wholesale & retail | 2003 |
| Mansfield Fire & Electrical (Engineers) Ltd | Public administration | 2017 |
| Mansfield Fire & Safety Management Limited | Construction | 2011 |
| Mansfield First AID Ltd | Education | 2017 |
| Mansfield Fish Bar Ltd | Hospitality | 2026 |
| Mansfield Garage Doors Limited | Construction | 1968 |
| Mansfield GP Services Limited | Health & social care | 2015 |
| Mansfield Homes Limited | Real estate | 2014 |
| Mansfield Interior Solutions Limited | Construction | 2016 |
| Mansfield Lawn Tennis Club Limited | Arts & recreation | 2017 |
| Mansfield Masonic Hall Company Limited(The) | Real estate | 1935 |
| Mansfield Mechanical Supplies Limited | Wholesale & retail | 2024 |
| Mansfield Medical Limited | Health & social care | 2023 |
| Mansfield Mini Market Ltd | Wholesale & retail | 2026 |
| Mansfield Mobile Valeting Ltd | Other services | 2019 |
| Mansfield Money Limited | Financial services | 2019 |
| Mansfield Mortgages & Protection Ltd | Financial services | 2019 |
| Mansfield MOT Service and Repairs Ltd | Wholesale & retail | 2020 |
| Mansfield Motor Homes Ltd | Wholesale & retail | 2014 |
| Mansfield Plastic Fabrications Limited | Manufacturing | 2003 |
| Mansfield Prestige Joinery Ltd | Construction | 2008 |
| Mansfield Property Improvements Ltd | Construction | 2025 |
| Mansfield PUB Company Limited | Hospitality | 2014 |
| Mansfield Rail Project Services Ltd | Professional & scientific | 2018 |
| Mansfield Realisations | Real estate | 1999 |
| Mansfield Refrigeration & Air Conditioning Ltd | Energy | 2023 |
| Mansfield Sand Company Limited | Mining & quarrying | 1999 |
| Mansfield Shutters Ltd | Wholesale & retail | 2023 |
| Mansfield Signs Ltd | Manufacturing | 2025 |
| Mansfield Soup Kitchen CIC | Wholesale & retail | 2019 |
| Mansfield Sprinkler Services Ltd. | Construction | 2003 |
| Mansfield Steel Services Limited | Manufacturing | 2003 |
| Mansfield Taxi Ltd | Construction | 2019 |
| Mansfield Tech Hub Limited | Other services | 2022 |
| Mansfield Town 1861 Limited | Other services | 2012 |
| Mansfield Town Developments Community Interest Company | Construction | 2015 |
| Mansfield Town Football Club Limited | Arts & recreation | 1922 |
| Mansfield Town Football in the Community Limited | Arts & recreation | 2008 |
| Mansfield Town Footwear & Clothing Ltd | Wholesale & retail | 2025 |
| Mansfield Tyre Centre Ltd | Wholesale & retail | 2025 |
| Mansfield Valeting Centre Ltd | Wholesale & retail | 2021 |
| Mansfield Van Hire Limited | Wholesale & retail | 2011 |
| Mansfield Woodhouse Bar Company Limited | Hospitality | 2025 |
| Mant Investments Ltd | Financial services | 2022 |
| Manílife Ltd | Manufacturing | 2015 |