| Oakwell Energy Consulting Limited | Administrative & support | 2008 |
| Oakwood Court BFD Limited | Health & social care | 2015 |
| Oakwood Equine Holdings Ltd | Wholesale & retail | 2024 |
| Oakwood Equine LLP | | 2021 |
| Oakwood Manor Estates Ltd | Professional & scientific | 2023 |
| Oakwood Manor Hospitality Ltd | Hospitality | 2025 |
| Oakwood Plastering and Renovations Leeds Limited | Construction | 2020 |
| Oakwood Yorkshire Ltd | Wholesale & retail | 2023 |
| Oakworth Medicare Ltd | Health & social care | 2023 |
| Oasis C R Limited | Administrative & support | 2009 |
| Oasis Limousines (Bradford) Ltd | Transport & logistics | 2011 |
| Oastler Foods Ltd | Hospitality | 2025 |
| Oates 3D Ltd | Manufacturing | 2026 |
| Oatlands Post Limited | Wholesale & retail | 2026 |
| OBO Yorkshire Ltd | Construction | 2025 |
| Obsidian Fire Engineering Solutions Ltd | Public administration | 2025 |
| Obsidian UK Holdings Ltd | Financial services | 2021 |
| Occasions by Jasmine Ltd | Wholesale & retail | 2021 |
| OCD Properties Ltd | Real estate | 2024 |
| OCD Refinishing Ltd | Wholesale & retail | 2020 |
| Ocean 9 Contracting Ltd | Construction | 2010 |
| Ocean Car Wash Ltd | Administrative & support | 2022 |
| Ocean City Apartments Ltd | Real estate | 2024 |
| Ocean City Developments Ltd | Real estate | 2023 |
| Ocean City Enterprise Ltd | Real estate | 2024 |
| Ocean Home Care Ltd | Health & social care | 2019 |
| Ocean Homes Limited | Construction | 2016 |
| Ocean Luggage Limited | Wholesale & retail | 2019 |
| Ocean Park Homes Limited | Construction | 2016 |
| Oceanline Ltd | Wholesale & retail | 2025 |
| Ocelot Fire Consultancy Limited | Public administration | 2022 |
| Ocis Locum Limited | Health & social care | 2021 |
| OCT Holding Ltd | Real estate | 2024 |
| Octagon Maintenance & Housing Group Ltd | Households | 2025 |
| Octane Investments Limited | Construction | 2019 |
| Octane Litigation Lawyers Ltd | Professional & scientific | 2024 |
| Octavian Catering Supplies Limited | Wholesale & retail | 2025 |
| Oculus Project Consulting Ltd | Professional & scientific | 2026 |
| Odaci Limited | Wholesale & retail | 2024 |
| ODC Events Bradford Limited | Hospitality | 2023 |
| ODD Jobbers (Yorkshire) Ltd | Professional & scientific | 2024 |
| Odogwu Plates Ltd | Hospitality | 2026 |
| Odsal Properties Limited | Real estate | 1998 |
| Odsal Top Barbers Ltd | Other services | 2025 |
| Odyssey (Concessions) Limited | Wholesale & retail | 1995 |
| Odyssey Homes Ltd | Households | 2025 |
| Odyssey Media House CIC | Manufacturing | 2024 |
| ODYSSEY12 Ltd | Manufacturing | 2025 |
| OET Executive Limited | Transport & logistics | 2017 |
| OF Group Ltd | Construction | 2024 |
| Ofentic Ltd | Wholesale & retail | 2024 |
| OFF Deck ROV Limited | Extraterritorial | 2015 |
| OFF the Hook Restaurant Group Limited | Hospitality | 2020 |
| Offclix Ltd | Wholesale & retail | 2025 |
| Office Clearance Team Ltd | Wholesale & retail | 2021 |
| Office Direct Ltd | Wholesale & retail | 2023 |
| Office Furnishers Limited | Wholesale & retail | 2025 |
| Office Furniture and Fixtures Supplies Ltd | Wholesale & retail | 2020 |
| Office Furniture Clearance Ltd | Wholesale & retail | 2020 |
| Office Furniture Express Limited | Wholesale & retail | 2025 |
| Office Furniture Yorkshire Limited | Wholesale & retail | 2018 |
| Office Orbit Limited | Administrative & support | 2025 |
| Officially Gorgeous Ltd | Manufacturing | 2020 |
| OG Waste Removal Services Ltd | Water & waste | 2025 |
| Ogho Ltd | Wholesale & retail | 2026 |
| OH SO YUM Limited | Manufacturing | 2025 |
| Ohana Hale Ltd | Wholesale & retail | 2020 |
| Ohealthcare Ltd | Health & social care | 2019 |
| Ohfs Limited | Financial services | 2001 |
| Ohri Properties Ltd | Real estate | 2024 |
| Oikos Family Centres Limited | Health & social care | 2018 |
| OJD Glob Limited | Health & social care | 2023 |
| OK TGC Ltd | Wholesale & retail | 2023 |
| Okaneservices Limited | Administrative & support | 2015 |
| OKB Build Ltd | Real estate | 2023 |
| OKS Empire Limited | Real estate | 2014 |
| OLA J Tasty Kitchen Limited | Hospitality | 2025 |
| Olabims Afrika Limited | Wholesale & retail | 2025 |
| Olada Limited | Real estate | 2025 |
| Oladirect Holdings Ltd | Wholesale & retail | 2025 |
| OLB73 Ltd | Hospitality | 2025 |
| Old Bird Ltd | Arts & recreation | 2025 |
| Old Co Leeds Limited | Hospitality | 2018 |
| Old Cotton Mill Ltd | Real estate | 2026 |
| Old Hall (Elmete) Limited | Real estate | 2012 |
| Old Lane (Nethertown) Management Limited | Households | 2023 |
| Old Mill Yard (Wilsden) Management Company Limited | Real estate | 2008 |
| Old Park Road Management Ltd | Construction | 2023 |
| Old School Building Yorkshire Ltd | Construction | 2026 |
| Oldboye Ltd | Arts & recreation | 2015 |
| Olde Country Bakery Limited | Extraterritorial | 2003 |
| Oldfield Deliveries Ltd | Transport & logistics | 2018 |
| Oldfield Motor Services Ltd | Wholesale & retail | 2023 |
| Oldgate Holdings Limited | Manufacturing | 2022 |
| Oldreed Limited | Wholesale & retail | 2019 |
| Oldroyd Building Limited | Construction | 2012 |
| OLE Joe's Holdings Ltd | Financial services | 2025 |
| Olive Branch Investments Ltd | Real estate | 2024 |
| Olive Bright Property Group Ltd | Real estate | 2023 |
| Olive Holistic Health Ltd | Health & social care | 2007 |