| Niche Yorkshire Limited | Professional & scientific | 2016 |
| Nicholas Property Investments Ltd | Real estate | 2025 |
| Nicola Wilson Equestrian Limited | Education | 2012 |
| Nigel Lightfoot Electrical Contracting Limited | Construction | 2003 |
| Nigel Phillips Contracting Services Limited | Agriculture & fishing | 2016 |
| NIL Property Limited | Real estate | 2006 |
| NIS Property Ltd | Administrative & support | 2021 |
| NJG Reporting Ltd | Health & social care | 2017 |
| NLG Group Limited | Financial services | 2018 |
| NO Fuss Websites Limited | Information & communication | 2025 |
| Nomad Systems Ltd | Information & communication | 1998 |
| Norcroft Electrical Ltd | Construction | 2005 |
| Nortelco Limited | Extraterritorial | 2010 |
| North Coast Yarns Ltd | Wholesale & retail | 2016 |
| North Moor Capital Ltd | Professional & scientific | 2025 |
| North Riding Developments Limited | Construction | 2016 |
| North Riding Financial Services Limited | Financial services | 2015 |
| North Yorkshire Bottling Ltd | Manufacturing | 2021 |
| North Yorkshire Building Company Limited | Professional & scientific | 2017 |
| North Yorkshire Citizens Advice & Law Centre Limited | Other services | 2011 |
| North Yorkshire County Agricultural Show | Other services | 2013 |
| North Yorkshire Forest School Training Limited | Education | 2009 |
| North Yorkshire Ltd | Professional & scientific | 2019 |
| Northallerton Acupuncture Clinic Ltd | Health & social care | 2011 |
| Northallerton Auctions Limited | Administrative & support | 1912 |
| Northallerton BID Company Limited | Public administration | 2017 |
| Northallerton EC Limited | Hospitality | 2019 |
| Northallerton Glass Limited | Manufacturing | 2015 |
| Northallerton Hair Clinic Ltd | Other services | 2021 |
| Northallerton Hair Limited | Other services | 2023 |
| Northallerton Insurance Services Ltd | Financial services | 2005 |
| Northallerton Joinery Limited | Construction | 2013 |
| Northallerton Local Store Ltd | Wholesale & retail | 2025 |
| Northallerton MM Ltd | Wholesale & retail | 2024 |
| Northallerton Osteopaths Limited | Other services | 2019 |
| Northallerton Riding Club Ltd | Arts & recreation | 2024 |
| Northallerton Rugby Club | Arts & recreation | 2018 |
| Northallerton Steel Erection Limited | Construction | 2002 |
| Northallerton Town Football Club Limited | Arts & recreation | 2020 |
| Northallerton Trade Centre Limited | Wholesale & retail | 2011 |
| Northallerton Traders Limited | Wholesale & retail | 2019 |
| Northallerton Web Solutions Ltd | Professional & scientific | 2026 |
| Northallertondecorators Ltd | Construction | 2020 |
| Northdale Horticulture Ltd | Health & social care | 2011 |
| Northern Edge Coaching Limited | Education | 2024 |
| Northern Industrial Sewing Machine Company Limited | Wholesale & retail | 2000 |
| Northshire Group Limited | Construction | 2023 |
| Nosterfield Management Company Limited | Real estate | 2020 |
| NR Convenience Ltd | Wholesale & retail | 2024 |
| NUN House Farm LLP | | 2023 |
| NW Turner Electrical Services Ltd | Construction | 2019 |
| NY Highways Limited | Construction | 2019 |
| O'Brien Fine Foods Leeming Bar Limited | Manufacturing | 2024 |
| O.T. Tallontire Ltd | Transport & logistics | 2021 |
| Oak Developments (Yorkshire) Limited | Real estate | 2006 |
| Oakvale Financial Ltd | Financial services | 2025 |
| Obetco Limited | Real estate | 2025 |
| Odana Cafe & Take Away Ltd | Hospitality | 2018 |
| Odana Shela Ltd | Hospitality | 2025 |
| Oddfellows Arms (Northallerton) Limited | Hospitality | 2015 |
| Oddfellows Arms N'Ton Ltd | Hospitality | 2024 |
| OJ Turbine Solutions Limited | Manufacturing | 2023 |
| Old Yorkshire Railway Sleepers Limited | Wholesale & retail | 2018 |
| Oleon Ltd. | Manufacturing | 1980 |
| Omega Business Village (Northallerton) Limited | Administrative & support | 2009 |
| Omega Developments (North East) Limited | Real estate | 2014 |
| Omega Marine Ltd | Professional & scientific | 2013 |
| Omnia Projects Limited | Administrative & support | 2012 |
| One Discovery Financial Services Ltd | Financial services | 2022 |
| One More Wine Shop Ltd | Wholesale & retail | 2021 |
| One North Property (Investments) Limited | Real estate | 2023 |
| One North Property Ltd | Construction | 2016 |
| One North Storage Ltd | Administrative & support | 2025 |
| Onfarmhatching Ltd | Agriculture & fishing | 2020 |
| Optikon Global Limited | Professional & scientific | 2016 |
| Oracle Surveying Ltd | Real estate | 2022 |
| OS Luxury Ltd | Wholesale & retail | 2024 |
| OS Services Ltd | Wholesale & retail | 2024 |
| Osmotherley Car Centre Limited | Wholesale & retail | 2022 |
| OSP Construction and Joinery Holdings Limited | Financial services | 2026 |
| OSP Construction and Joinery Limited | Construction | 2022 |
| OSW Properties (Jesmond) Limited | Real estate | 2020 |
| OTW Partners Limited | Financial services | 2025 |
| Ouseview Driver Training Ltd | Education | 2023 |
| Ovashonna Limited | Other services | 2022 |
| Owens Grouse Grit Limited | Manufacturing | 2010 |
| OWL Residential Lettings Ltd | Real estate | 2020 |
| P & C Autotek Limited | Wholesale & retail | 2008 |
| P & L Atkinson Limited | Arts & recreation | 2019 |
| P J D Agencies Limited | Wholesale & retail | 2006 |
| P T Makin Property Limited | Real estate | 2022 |
| P W & S I Stelling & SON Limited | Wholesale & retail | 2016 |
| Pack a Sack Ltd | Administrative & support | 2025 |
| Packaging Services UK Limited | Manufacturing | 2005 |
| Pacno Holidays Ltd | Hospitality | 2023 |
| Pageroll Limited | Professional & scientific | 1984 |
| Pangie Media Limited | Information & communication | 2026 |
| Papillon Portfolio Builder Ltd | Real estate | 2019 |
| Papillon Property Group Ltd | Real estate | 2019 |
| Park View Management (Huddersfield) Limited | Real estate | 2007 |