| Migrations Ltd | Information & communication | 2014 |
| Migreenkitchen Ltd | Manufacturing | 2022 |
| Mihran Foods Ltd | Hospitality | 2025 |
| Mike Sanderson PIX Ltd | Manufacturing | 2020 |
| Mike Smit Education Ltd | Education | 2015 |
| Military in Art Ltd | Arts & recreation | 2022 |
| Mill House Childcare Ltd | Education | 2022 |
| Mill House Club Ltd | Health & social care | 2017 |
| Mill House Nursery Escrick Ltd | Education | 2022 |
| Mill House Property Group Ltd | Financial services | 2024 |
| Mill Lane Stables Limited | Arts & recreation | 2010 |
| Millbrook Power Limited | Administrative & support | 2014 |
| Millgate Property Solutions Ltd | Construction | 2025 |
| Millington (Farms) Limited | Agriculture & fishing | 1974 |
| Mindis Car Limited | Transport & logistics | 2024 |
| Mindspace Psychology Ltd | Health & social care | 2017 |
| Minerva IO Ltd | Information & communication | 2026 |
| Minster Mobility Ltd | Wholesale & retail | 2009 |
| Miron MC Limited | Transport & logistics | 2016 |
| Miss Tree Games Limited | Manufacturing | 2025 |
| Miss W Productions Limited | Information & communication | 2019 |
| Mister M Productions Limited | Information & communication | 2017 |
| Mitzi (UK) Limited | Health & social care | 2014 |
| MJ Couriers and Removals Ltd | Transport & logistics | 2019 |
| MJ Gora Ltd | Transport & logistics | 2026 |
| MJC Design Ltd | Professional & scientific | 2019 |
| MJD Project Management Limited | Professional & scientific | 2023 |
| Mjperry Electrical Limited | Professional & scientific | 2008 |
| MK1 Gym Ltd | Arts & recreation | 2023 |
| MODE44 Ltd | Information & communication | 2016 |
| Modular Equipment Ltd | Manufacturing | 2019 |
| Monkey Wrench Ltd | Wholesale & retail | 2017 |
| Moorside Building Supplies Limited | Wholesale & retail | 1988 |
| Morris Leslie (Selby) Limited | Real estate | 1995 |
| Morris Pearse Developments Ltd | Real estate | 2025 |
| Mortgage Administration Services Limited | Financial services | 2018 |
| Morton Lane (E-C) Ltd | Arts & recreation | 2009 |
| Mouth Boss Ltd | Wholesale & retail | 2024 |
| MR Green Hands Ltd | Administrative & support | 2009 |
| MR Gyros Food Ltd | Hospitality | 2024 |
| MR Robinson at Duty Limited | Arts & recreation | 2025 |
| MRH Projects York Ltd | Construction | 2022 |
| MS Abode Ltd | Construction | 2020 |
| MS Land & Construction Services Ltd. | Professional & scientific | 2018 |
| MS PI Selby Ltd | Construction | 2026 |
| MS Property Refurbs Ltd | Construction | 2025 |
| MSA Foods Selby Ltd | Hospitality | 2024 |
| Mscm Legacy Property Ltd | Real estate | 2026 |
| Muaythai GB Community Interest Company | Arts & recreation | 2022 |
| Mummyfit (Selby and York) Ltd | Other services | 2023 |
| Munchkins Day Nursery (Selby) Limited | Health & social care | 2014 |
| MVA GAS Spares Limited | Wholesale & retail | 2014 |
| MWC Film Productions Limited | Information & communication | 2021 |
| My Local Selby Ltd | Wholesale & retail | 2024 |
| Mylo Trading Limited | Real estate | 2023 |
| N16BLB Training Limited | Construction | 2022 |
| Nadine Meillam Limited | Professional & scientific | 2013 |
| Nash Electrical Installations Ltd | Construction | 2017 |
| Natalya Film Productions Limited | Information & communication | 2019 |
| National TM Selby Limited | Administrative & support | 2023 |
| Nationwide Catering Services Limited | Manufacturing | 1953 |
| Nationwide Locksmiths Limited | Manufacturing | 2014 |
| Naturally YOU Emotional Space Ltd | Wholesale & retail | 2026 |
| NCM Services Limited | Agriculture & fishing | 2018 |
| NDJ Plumbing & Heating Limited | Construction | 2014 |
| Neal Heritage + Architecture Ltd | Professional & scientific | 2022 |
| Needle Media Ltd | Information & communication | 2016 |
| Neenor Fire Ltd | Public administration | 2024 |
| Neolea Wellbeing Ltd | Other services | 2023 |
| Nevermore Productions Limited | Information & communication | 2019 |
| New 44 Pizza Ltd | Hospitality | 2024 |
| New Inn, Cliffe Limited | Hospitality | 2024 |
| New Vision Granite Ltd | Construction | 2018 |
| Newhay Lakes Ltd | Agriculture & fishing | 2013 |
| Nexline Global Ltd | Administrative & support | 2026 |
| NF Residential Ltd | Real estate | 2021 |
| NICBAN06 Limited | Information & communication | 2026 |
| Nicky Franks Ltd | Professional & scientific | 2016 |
| Night Shift Servicing Ltd | Wholesale & retail | 2016 |
| Nimrod Phoenix Limited | Manufacturing | 2021 |
| Nine Realms Tours Ltd | Arts & recreation | 2026 |
| Nishi Mahajan Consulting Ltd | Professional & scientific | 2026 |
| NJW Composite Doors Ltd | Construction | 2022 |
| NJW Windows and Doors Ltd | Construction | 2026 |
| Nomtom Limited | Administrative & support | 2024 |
| Noodles Web Limited | Information & communication | 2013 |
| Noone Investments Ltd | Real estate | 2024 |
| North American Science Associates Limited | Professional & scientific | 1998 |
| North Bay Barbershop Ltd | Other services | 2025 |
| North Eastern Driving Trials Limited | Arts & recreation | 1997 |
| North Point Living Developments Ltd | Construction | 2013 |
| North West Lead Holdings Ltd | Financial services | 2019 |
| North West Lead Limited | Construction | 1995 |
| Northern Door Solutions Ltd | Construction | 2023 |
| Northern Heating & Plumbing Services Limited | Construction | 2008 |
| Northpoint Living Limited | Households | 2011 |
| Northvia Consulting Ltd | Professional & scientific | 2026 |
| Norĵi Ltd | Information & communication | 2026 |
| NRH Property Development Limited | Real estate | 2017 |
| NRT Freight Services Limited | Transport & logistics | 2012 |