| Nebulon Technologies Ltd | Information & communication | 2014 |
| Neon Media Limited | Information & communication | 2015 |
| Nero Communications Limited | Information & communication | 2017 |
| Netherfield Beauty Ltd | Other services | 2025 |
| Netm Properties Ltd | Real estate | 2025 |
| Network Brands Limited | Wholesale & retail | 2001 |
| New Star Publishing Ltd. | Information & communication | 2014 |
| New Star R&D Ltd | Information & communication | 2021 |
| Nexlynk Solutions Limited | Information & communication | 2001 |
| Nexus Workspace Limited | Construction | 2009 |
| NIC Paige Solutions Limited | Information & communication | 2018 |
| Nightingale Property Maintenance & Repairs Ltd | Construction | 2024 |
| NO.1 Search Limited | Administrative & support | 2024 |
| Noisy COW Theatre Co. CIC | Arts & recreation | 2025 |
| North Property Investments Limited | Real estate | 2001 |
| Northern Monkey Tuning Ltd | Wholesale & retail | 2025 |
| Northern Sports Surfaces Ltd | Construction | 2007 |
| Northone Components Limited | Other services | 2018 |
| Nourishing Care Ltd | Health & social care | 2025 |
| Novaa Beauty Clinic Ltd | Other services | 2025 |
| O Padel Limited | Arts & recreation | 2025 |
| O.G.I Electrical Limited | Construction | 2017 |
| OB Group Holdings Limited | Financial services | 2022 |
| OGJ Group Ltd | Construction | 2025 |
| OJS Removals Ltd | Transport & logistics | 2023 |
| Old Town Trading Ltd | Wholesale & retail | 2016 |
| Oldroyd Maintenance Services Ltd | Manufacturing | 2010 |
| Olive Tree Wealth Management Ltd | Financial services | 2013 |
| Oliver Pinder Ltd | Arts & recreation | 2023 |
| Oliver Wholesale Services Limited | Wholesale & retail | 2024 |
| Olmc (UK) Limited | Extraterritorial | 2012 |
| Olmc E Compliance Ltd | Professional & scientific | 2023 |
| Olmc Group Limited | Professional & scientific | 2024 |
| Olmc Training Limited | Professional & scientific | 2009 |
| Omvantis Ltd | Financial services | 2025 |
| Oncloud Hosting Limited | Information & communication | 2002 |
| One Breath Gaming Ltd | Arts & recreation | 2017 |
| One Design Architects Ltd | Professional & scientific | 2013 |
| One Stop Barbers (Ossett) Ltd | Other services | 2026 |
| Open Roam C.I.C. | Education | 2025 |
| Operator Licence Maintenance Consultants Ltd | Transport & logistics | 2015 |
| Orange Heaven Limited | Information & communication | 2005 |
| Origin Electrical and Mechanical Services Ltd | Construction | 2023 |
| Osset Car Wash Limited | Administrative & support | 2026 |
| Ossett 888 Ltd | Hospitality | 2024 |
| Ossett Ace of Fades Ltd | Other services | 2026 |
| Ossett Annex Ltd | Hospitality | 2024 |
| Ossett Beds Ltd | Manufacturing | 2022 |
| Ossett Box Limited | Manufacturing | 1995 |
| Ossett Brewery Group Holdings Limited | Financial services | 2016 |
| Ossett Brewery PUB Company Limited | Hospitality | 2004 |
| Ossett Brewing Company Limited | Manufacturing | 1997 |
| Ossett Catering Limited | Hospitality | 2026 |
| Ossett Contract Services Ltd | Construction | 2012 |
| Ossett Cricket & Athletic Club Community Interest Company | Arts & recreation | 2025 |
| Ossett Dental Care Limited | Health & social care | 2023 |
| Ossett Emporium Ltd | Wholesale & retail | 2020 |
| Ossett Enterprises Limited | Transport & logistics | 2023 |
| Ossett Fish & Chips Ltd | Hospitality | 2025 |
| Ossett Holdings Limited | Financial services | 2015 |
| Ossett Leisure Ltd | Arts & recreation | 2023 |
| Ossett M.O.T. Testing Centre Limited | Wholesale & retail | 1980 |
| Ossett Occupational Health Ltd | Other services | 2023 |
| Ossett Padel Co Ltd | Arts & recreation | 2026 |
| Ossett Plumbing Supplies Limited | Extraterritorial | 2023 |
| Ossett Property Co. Limited | Real estate | 1977 |
| Ossett Rugby Union Football Club Limited | Arts & recreation | 2015 |
| Ossett Spice Limited | Hospitality | 2025 |
| Ossett Tyres & Autos (Ossett) Ltd | Wholesale & retail | 2025 |
| Ossett Tyres Ltd | Wholesale & retail | 2025 |
| Ossett United Ltd | Arts & recreation | 2018 |
| Ottomans & Beds Ltd | Manufacturing | 2015 |
| OUR Agency in the North Limited | Professional & scientific | 2007 |
| OUR Gym Ltd | Arts & recreation | 2023 |
| Outback Oddities Ltd | Wholesale & retail | 2025 |
| Outdoor World (UK) Limited | Wholesale & retail | 2003 |
| Outreach Developments Ltd | Real estate | 2025 |
| Outside in Management Limited | Professional & scientific | 2008 |
| Oven Restore Limited | Other services | 2016 |
| Owen JOE Limited | Professional & scientific | 2023 |
| OWL Lane Farm Nurseries Limited | Wholesale & retail | 2010 |
| Owlers Solar Ltd | Energy | 2026 |
| Oydt Limited | Real estate | 2024 |
| Ozzy’S Petcare Ltd | Manufacturing | 2025 |
| P and B Transport Limited | Transport & logistics | 2007 |
| Pace UK Hire Ltd | Administrative & support | 2026 |
| Padauk Carpentry & Joinery Limited | Construction | 2022 |
| Padauk Properties Limited | Real estate | 2020 |
| Padgett Brothers (a to Z) Limited | Wholesale & retail | 1985 |
| Panel & Paint Ossett Limited | Wholesale & retail | 2019 |
| Panther Trikes Limited | Wholesale & retail | 2014 |
| Paragon Restaurants Limited | Hospitality | 2017 |
| Parcels to Freight Ltd | Transport & logistics | 2009 |
| Park Grange Estate Limited | Real estate | 2015 |
| Parkes Group (Yorkshire) Ltd | Construction | 2024 |
| Partip Ltd | Hospitality | 2017 |
| Pathfinder Logistics Ltd | Transport & logistics | 2020 |
| Paul Oliver Painter and Decorator Ltd | Construction | 2024 |
| Paul the Publican Limited | Hospitality | 2025 |
| Pavilion Italian Ltd | Hospitality | 2025 |