| Marlow Place Management Ltd | Real estate | 2020 |
| Marlow Podcast Co Ltd | Administrative & support | 2026 |
| Marlow Project Planning Services Ltd | Professional & scientific | 2018 |
| Marlow Property Group Limited | Real estate | 2019 |
| Marlow Residential Limited | Real estate | 2024 |
| Marlow Rowing Club | Arts & recreation | 2012 |
| Marlow Rowing Club Trading Limited | Arts & recreation | 2012 |
| Marlow Sports Club Limited | Arts & recreation | 1961 |
| Marlow Street Kitchen Limited | Hospitality | 2025 |
| Marlow Studio Pottery Ltd | Education | 2024 |
| Marlow Tailoring Limited | Other services | 2019 |
| Marlow Tandoori Ltd | Manufacturing | 2025 |
| Marlow Tattoo Lounge Ltd | Arts & recreation | 2018 |
| Marlow Town Regatta and Festival | Arts & recreation | 2008 |
| Marlow TV & Film Tours Ltd | Administrative & support | 2025 |
| Marlow VA Ltd | Administrative & support | 2023 |
| Marlow VIP Grooming Limited | Other services | 2025 |
| Marlow Youth and Community Centre Ltd | Health & social care | 2011 |
| Marsh Estates Limited | Real estate | 2017 |
| Martin LEE Tennis LLP | | 2009 |
| Marvellous Property Company Ltd | Real estate | 2012 |
| Mason and Booth Limited | Wholesale & retail | 2023 |
| Massage Marlow Ltd | Health & social care | 2025 |
| Master Brands International Limited | Extraterritorial | 1993 |
| Matoski Ltd | Information & communication | 2014 |
| Matt Snowball Music Limited | Administrative & support | 2008 |
| Matthew Gaunt Associates Ltd | Professional & scientific | 2020 |
| Matthew Gray Limited | Administrative & support | 2003 |
| Matts Propco LLP | | 2021 |
| MAX Impact Transformation Ltd | Professional & scientific | 2018 |
| Maxa Consultancy Limited | Financial services | 2022 |
| Maxxess Systems Europe Limited | Information & communication | 1998 |
| MAY Wheeler Group Ltd | Professional & scientific | 2025 |
| Mayfield Accounting Limited | Professional & scientific | 2004 |
| Mayfield Mews Residents Management Company Limited | Households | 2007 |
| MB Screed Limited | Construction | 2010 |
| Mclure James Limited | Professional & scientific | 2014 |
| MCO Lettings Bucks Ltd | Real estate | 2013 |
| MD Heliports Equipment Ltd | Wholesale & retail | 2017 |
| Mdcorrick Plumbing & Heating Ltd | Construction | 2010 |
| MDM (Bucks) Limited | Professional & scientific | 2017 |
| MDM Technik Limited | Wholesale & retail | 2010 |
| ME Films Limited | Information & communication | 2018 |
| ME My Chins and I Limited | Health & social care | 2023 |
| Medas Solutions Limited | Professional & scientific | 2009 |
| Medi Campusglobal Limited | Construction | 2024 |
| Media Friendly Limited | Other services | 2019 |
| Medical & Water Safety Limited | Health & social care | 2016 |
| Medix Consultancy Ltd | Professional & scientific | 2024 |
| Medmenham Firewood Ltd | Wholesale & retail | 2019 |
| Melanie Chak Limited | Health & social care | 2022 |
| Melissa and Doug Ltd | Wholesale & retail | 2018 |
| Melo Auto Repairs Ltd | Wholesale & retail | 2015 |
| Meltingclock Ltd. | Professional & scientific | 2015 |
| Melvin's Folly Residents Management Limited | Households | 1990 |
| Memory Distribution Ltd | Information & communication | 2019 |
| MEN of Spire Music Limited | Administrative & support | 2005 |
| Mercatum LLP | | 2018 |
| Merelafan Developments Henley Road Ltd | Construction | 2013 |
| Merrys Limited | Wholesale & retail | 2007 |
| Messenger Properties Ltd | Real estate | 2021 |
| Messy Organics Limited | Manufacturing | 2023 |
| Metanoia Pharma Ltd | Wholesale & retail | 2023 |
| MGN Strategy Limited | Professional & scientific | 2025 |
| MHP Global Limited | Financial services | 2019 |
| MHP Industries Group Ltd | Manufacturing | 2024 |
| MI Pharmaceuticals Limited | Health & social care | 2024 |
| Michael Spracklen Limited | Real estate | 1986 |
| Middle Field Medical Limited | Health & social care | 2015 |
| Midlands Hockey Ltd | Arts & recreation | 2018 |
| Midlands Technical Mouldings Limited | Manufacturing | 2005 |
| Midsummer Place (Asheridge Road) Chesham Management Limited | Households | 2018 |
| Miktell (Distribution) Ltd | Wholesale & retail | 2021 |
| Miktell Ltd | Wholesale & retail | 2012 |
| Mile Away Investments Ltd | Real estate | 2015 |
| Mill Bay Case Management and OT Limited | Health & social care | 2023 |
| Millbank Management (Marlow) Limited | Households | 1985 |
| Millipedia Limited | Information & communication | 2005 |
| Milne Digital Publishing Limited | Information & communication | 2014 |
| Mind Body Mentor Limited | Health & social care | 2018 |
| Mindanao Investments Limited | Hospitality | 2026 |
| Mint Operations Ltd | Administrative & support | 2026 |
| MIR Medical Solutions Ltd | Administrative & support | 2026 |
| Mirchev Limited | Other services | 2011 |
| Mirror Entertainment Limited | Information & communication | 2013 |
| Mischief Maker Limited | Professional & scientific | 2024 |
| Mishatree Limited | Information & communication | 2020 |
| MJD Civil Engineering Ltd | Construction | 2019 |
| MKB Designs Limited | Construction | 2019 |
| MKB Medical Ltd. | Health & social care | 2013 |
| MKR Electrical Services Limited | Construction | 2007 |
| MLL 32GHZ Limited | Information & communication | 2014 |
| MLL 40GHZ Limited | Information & communication | 2014 |
| MLL Telecom Ltd. | Information & communication | 1991 |
| MM Woodworking Limited | Manufacturing | 2014 |
| MMC Management Limited | Administrative & support | 2016 |
| MMG Games Consulting Limited | Information & communication | 2006 |
| Mobco Limited | Financial services | 2022 |
| Mode Residents Management Company Limited | Households | 2003 |
| Modern Leaders Ltd | Professional & scientific | 2020 |