| Newett Pudsey Ltd | Construction | 2026 |
| Newett Roberts Limited | Construction | 2021 |
| Newleaf Associates Limited | Wholesale & retail | 2013 |
| Newman Family Holdings Ltd | Financial services | 2024 |
| Newton Control Services Ltd | Construction | 2025 |
| Nexnet Ltd | Information & communication | 2026 |
| Nexus Healthhub Ltd | Health & social care | 2024 |
| NH Construction Brickwork and Masonry Ltd | Construction | 2018 |
| NH Trustees Limited | Financial services | 2023 |
| NHL Giggleswick Limited | Real estate | 2024 |
| Nick DEE Property Ltd | Real estate | 2023 |
| Nicolla Florist Limited | Wholesale & retail | 2020 |
| Nigel Hunter Ltd | Professional & scientific | 2023 |
| Nigel Ingram Developments Ltd | Construction | 2014 |
| Niknab Limited | Administrative & support | 2018 |
| NINETEEN47 Investments Ltd | Real estate | 2021 |
| Nippers Properties Ltd | Real estate | 2018 |
| NL Formulations Limited | Manufacturing | 2004 |
| NM Resource Solutions Ltd | Administrative & support | 2024 |
| NO Limbit Ltd | Arts & recreation | 2021 |
| NO5 Beauty (Wetherby) Limited | Other services | 2020 |
| Nomal Properties Limited | Real estate | 2026 |
| Norcap Ltd | Professional & scientific | 2026 |
| Noreast Limited | Professional & scientific | 2012 |
| North Leeds Builders Limited | Construction | 2011 |
| North Leeds Kitchens Limited | Construction | 2018 |
| North Lodge (York) Management Company Limited | Households | 2020 |
| North Point Property Consultants Ltd | Real estate | 2019 |
| North Wave Design Limited | Professional & scientific | 2022 |
| North Yorkshire Financial Planning Ltd | Financial services | 2020 |
| Northallerton Denture Clinic Limited | Health & social care | 2017 |
| Northcote Fold Management Company Limited | Households | 2015 |
| Northern Roots Holdings Ltd | Financial services | 2024 |
| Northern Roots Properties Ltd | Real estate | 2024 |
| Northfield Site Services Ltd | Construction | 2019 |
| Nougat International Limited | Wholesale & retail | 2023 |
| Novito Limited | Real estate | 2020 |
| NPJ Property Group Ltd | Real estate | 2019 |
| NR Property Services Ltd | Construction | 2019 |
| NTR EOT Limited | Administrative & support | 2024 |
| NU Group Limited | Construction | 2015 |
| Numbers YOU Need Ltd | Professional & scientific | 2026 |
| Nunnery Way (Clifford) Management Company Limited | Households | 2014 |
| Nxip Ltd | Professional & scientific | 2025 |
| NY Smokehouse Ltd | Hospitality | 2022 |
| Nymen Spence Ltd | Administrative & support | 2002 |
| Nymor Ltd | Real estate | 2012 |
| O & J Homes Ltd | Real estate | 2018 |
| O Strands Ltd | Manufacturing | 2021 |
| O&J Property Investments Ltd | Real estate | 2020 |
| O. Kent Property Ltd | Construction | 2018 |
| Oak Leasing (UK) Limited | Administrative & support | 2001 |
| Oak Motors (Wetherby) Limited | Wholesale & retail | 2010 |
| Oakacre Land Ltd | Construction | 2025 |
| Oakdale Estates Limited | Construction | 2010 |
| Oakdale Lettings Limited | Real estate | 2022 |
| Oakgate (Bradford) Limited | Extraterritorial | 1997 |
| Oakgate (Monks Cross) Limited | Extraterritorial | 2003 |
| Oakgate (Roadside) Limited | Extraterritorial | 2003 |
| Oakgate (Rotherham) LLP | | 2008 |
| Oakgate Central York Limited | Real estate | 2007 |
| Oakgate City Living Limited | Construction | 2000 |
| Oakgate Group Limited | Real estate | 1995 |
| Oakgate HQ Limited | Extraterritorial | 2002 |
| Oakgate Offices Limited | Extraterritorial | 2002 |
| Oakgate Project Management Limited | Extraterritorial | 1998 |
| Oakgate Yorkshire Limited | Real estate | 1999 |
| Oaklands Wetherby Limited | Wholesale & retail | 1988 |
| Oakwood Grange (Emley) Management Company Limited | Real estate | 2025 |
| Oasis Bidco 4 Limited | Financial services | 2026 |
| Oasis Foundation | Education | 1999 |
| OCK Consulting Ltd | Professional & scientific | 2021 |
| Office Space Limited | Real estate | 2015 |
| OGP Investments Limited | Financial services | 2025 |
| OH Bayby 7 Limited | Hospitality | 2023 |
| OH Social Ltd | Information & communication | 2023 |
| Old Lane Consulting Limited | Professional & scientific | 2025 |
| Old School Walk Estate Management Company Ltd | Real estate | 2026 |
| Old School Walk Freehold Management Company Ltd | Real estate | 2026 |
| Old Star Garage Collingham Ltd | Wholesale & retail | 2020 |
| Olive Branch Kitchens Ltd | Construction | 2008 |
| Oliver Willard Ltd | Construction | 2010 |
| Olivia Grace Wetherby Limited | Wholesale & retail | 2011 |
| OM Lifestyle Limited | Wholesale & retail | 2020 |
| ON Every Trip Ltd | Information & communication | 2025 |
| ON Friday Ltd | Arts & recreation | 2019 |
| ON Thyme Logistics Limited | Transport & logistics | 2023 |
| On-Demand Mobility Services Limited | Administrative & support | 2013 |
| On-Site Property Solutions Limited | Real estate | 2015 |
| One for the City CIC | Other services | 2022 |
| Ontime Business Services Ltd | Administrative & support | 2012 |
| Optima Transport Limited | Transport & logistics | 2023 |
| Orange Crush Digital Ltd | Professional & scientific | 2015 |
| Orbis Building Services Consultants Limited | Professional & scientific | 2020 |
| Orbis Consultancy Limited | Financial services | 2017 |
| Orbit Business Development Ltd | Information & communication | 2002 |
| Orchids Retreat Limited | Other services | 2015 |
| Orion Project Services Limited | Professional & scientific | 2025 |
| Orton Innovation Services Ltd | Professional & scientific | 2016 |
| Oshua Limited | Information & communication | 2016 |