| Longborough Developments Limited | Construction | 1965 |
| Loop Software Ltd | Information & communication | 2017 |
| Lora Nova Bridal Limited | Wholesale & retail | 2020 |
| Lora Nova Design Consulting Limited | Wholesale & retail | 2018 |
| Love Londres Limited | Administrative & support | 2015 |
| Lower Manor Farm Hospitality Limited | Hospitality | 2022 |
| LRJ Accountancy Services Limited | Professional & scientific | 2005 |
| Luckley Holidays LLP | | 2023 |
| Lucky Piglet Design Ltd | Professional & scientific | 2025 |
| Lucye Deacon Limited | Professional & scientific | 2008 |
| Lunarya Ltd | Wholesale & retail | 2021 |
| Lynx Jaguar Limited | Manufacturing | 2024 |
| Lynx Sports Cars Limited | Manufacturing | 2024 |
| Lyon Corporation Ltd | Wholesale & retail | 2024 |
| M D Surgery Limited | Health & social care | 2015 |
| M P Allen Builders and Contractors Limited | Construction | 2004 |
| M.J.D. Fabrications Limited | Manufacturing | 2024 |
| Mace-Ng-Design Ltd | Professional & scientific | 2017 |
| Machinery Sales Direct Ltd | Wholesale & retail | 2021 |
| MAD Keen Productions Ltd | Information & communication | 2025 |
| MAE Cotswolds Ltd | Hospitality | 2026 |
| Maggie Turner Limited | Professional & scientific | 2004 |
| Magna Buildings Limited | Construction | 1987 |
| Maison 10 Limited | Professional & scientific | 2018 |
| Mangan & Webb Limited | Wholesale & retail | 2008 |
| Marchingwell Associates Limited | Real estate | 2013 |
| Mark a. Jones Fine Art & Antiques Limited | Wholesale & retail | 2015 |
| Marlbrook Farming Limited | Real estate | 2015 |
| Martin Collins Limited | Real estate | 2023 |
| Massimo Hospitality Ltd | Hospitality | 2025 |
| Maugersbury Fields Limited | Extraterritorial | 2014 |
| Maynell Investments Limited | Financial services | 2024 |
| Measurement Technologies Limited | Information & communication | 2005 |
| Menopause Doctors Group Ltd | Administrative & support | 2026 |
| Menopause Resolutions Ltd | Administrative & support | 2024 |
| Mers Solutions Ltd | Wholesale & retail | 2014 |
| Midland Land Developments Limited | Construction | 2003 |
| Mike Jackson Eventing Limited | Arts & recreation | 2024 |
| Mill Close Management Company Limited | Real estate | 2001 |
| MMI Cleaning Ltd | Administrative & support | 2024 |
| Mobile Transport Services Limited | Professional & scientific | 2018 |
| Mojo Technical Consulting Ltd | Professional & scientific | 2025 |
| Moreton Food Ltd | Hospitality | 2025 |
| Moreton-In-Marsh and District Agricultural and Horse Show Society | Other services | 1989 |
| Morthodontics Limited | Health & social care | 2018 |
| Music Masters Limited | Arts & recreation | 1977 |
| MVS Consulting Limited | Real estate | 2015 |
| Mythic Feast Ltd. | Hospitality | 2015 |
| Nature Investment Group Ltd | Professional & scientific | 2021 |
| Naustar Ltd | Manufacturing | 2016 |
| Neighbrook Consulting Ltd | Professional & scientific | 2022 |
| Ness Consultancy Ltd | Administrative & support | 2016 |
| Nevi Paints Ltd | Professional & scientific | 2022 |
| New England Coffee House Ltd | Hospitality | 2022 |
| Nexfield Developments Limited | Real estate | 2010 |
| Nexus Electrical (Cotswolds) Ltd | Construction | 2024 |
| Nicholas James Creative Limited | Professional & scientific | 2021 |
| Nicola Lincoln Ltd | Professional & scientific | 2006 |
| Nikki Hill Coaching Ltd | Health & social care | 2020 |
| Nimrod Veterinary Products Limited | Wholesale & retail | 2007 |
| Norfolk Menopause Limited | Administrative & support | 2023 |
| North Cotswold Group Limited | Professional & scientific | 2022 |
| North Cotswold Landscaping Ltd | Administrative & support | 2021 |
| North Cotswolds Business Group CIC | Other services | 2021 |
| North Cotswolds Media Ltd | Information & communication | 2025 |
| North Four Shire Stone Farm Ltd | Agriculture & fishing | 2023 |
| North Pole Trading Ltd | Hospitality | 2025 |
| Northam Construction Limited | Real estate | 2002 |
| Northwick Electricity Limited | Energy | 2011 |
| Northwick Holdings Limited | Extraterritorial | 2015 |
| Northwick Mansion Company Limited | Real estate | 1989 |
| Northwick Power Services Limited | Professional & scientific | 2015 |
| Northwick Private Hire Limited | Transport & logistics | 2024 |
| Number 1 2020 Ltd | Wholesale & retail | 2019 |
| Nursery Days Limited | Education | 2006 |
| Nvisualise Ltd | Professional & scientific | 2009 |
| OAC Construction Consultants Limited | Professional & scientific | 2024 |
| Oaks Architectural Limited | Professional & scientific | 2015 |
| OB Cheltenham Limited | Wholesale & retail | 2025 |
| OHU Ltd | Wholesale & retail | 2023 |
| OJE Technology Limited | Information & communication | 2016 |
| Old Bikes Limited | Wholesale & retail | 2015 |
| Old School Rural Limited | Other services | 2025 |
| OLI H Limited | Wholesale & retail | 2026 |
| Omnia Estates & Trusts Limited | Other services | 2022 |
| ON Board Festival Food Limited | Hospitality | 2015 |
| One Big Spirit Limited | Extraterritorial | 2022 |
| One Thornhill Crescent Property Management Ltd | Households | 2004 |
| Oneseat Limited | Wholesale & retail | 2011 |
| Open Mind Distribution Limited | Wholesale & retail | 2013 |
| Orchidale Childrens Nursery Limited | Education | 2014 |
| Oread Limited | Financial services | 2025 |
| Orpheus Developments Ltd. | Construction | 2017 |
| Orsett Hall Limited | Other services | 2021 |
| Otis & Belle Bakeries Ltd | Manufacturing | 2022 |
| Otis & Belle Broadway Ltd | Wholesale & retail | 2024 |
| Otis & Belle Ltd | Wholesale & retail | 2020 |
| Otis & Belle Stow Ltd | Wholesale & retail | 2021 |
| OTS Group Limited | Wholesale & retail | 1971 |
| Overwatch Technology Solutions Limited | Administrative & support | 2024 |