| Okenla Chambers Limited | Professional & scientific | 2019 |
| Okonji Properties Ltd | Real estate | 2025 |
| Okpotokpo Adaigbo Niile Worldwide UK Chapter Ltd | Education | 2020 |
| Oktan Investments Limited | Real estate | 2023 |
| Okular Records Limited | Information & communication | 2024 |
| Okuns Venture Ltd | Other services | 2020 |
| OLA Commerical Enterprises Ltd | Wholesale & retail | 2013 |
| OLA Communication and Electrical Limited | Transport & logistics | 2014 |
| Ola-Ariyoh Holding Ltd. | Health & social care | 2019 |
| Olaartgallery Limited | Arts & recreation | 2025 |
| Olad IT Services Limited | Information & communication | 2019 |
| Olajumoke Banjo Company Ltd | Health & social care | 2020 |
| Olevion Pure Ltd | Administrative & support | 2026 |
| Olice Foods Limited | Wholesale & retail | 2024 |
| Olive Gardens Investment Ltd | Real estate | 2024 |
| Olivehaus Ltd | Real estate | 2025 |
| Oliveira Painting Decoration Ltd | Construction | 2026 |
| Olivine Healthcare Solutions Ltd | Administrative & support | 2025 |
| Olix Decorating Ltd | Construction | 2018 |
| Olori’S Enterprises Ltd | Arts & recreation | 2026 |
| Oluk Ltd | Wholesale & retail | 2022 |
| Olympia Solutions Limited | Transport & logistics | 2020 |
| Olympus Dine Limited | Hospitality | 2025 |
| OM Foods PVT Ltd | Hospitality | 2025 |
| Omar Exotic Foods Limited | Wholesale & retail | 2017 |
| Omega Cars Limited | Transport & logistics | 2019 |
| Omega Solicitors & Advocates Ltd | Professional & scientific | 2023 |
| OMG EYE CAN SEE Ltd | Health & social care | 2015 |
| Omihani Rail and Construction Company Ltd | Construction | 2014 |
| Omni Lens (PVT.) Ltd | Health & social care | 2021 |
| Omnireach Limited | Information & communication | 2024 |
| Omnixor Global Ltd | Wholesale & retail | 2025 |
| Omoghene Trading Services Ltd | Transport & logistics | 2018 |
| Omoh Enterprises Limited | Transport & logistics | 2026 |
| ON Beuty Limited | Wholesale & retail | 2021 |
| ONA KEV Ltd | Administrative & support | 2025 |
| One Click Deals Ltd | Wholesale & retail | 2024 |
| One Click Shop Ltd | Wholesale & retail | 2025 |
| One M M Limited | Administrative & support | 2024 |
| One NIC UK Limited | Extraterritorial | 2019 |
| One Room Live CIC | Professional & scientific | 2021 |
| One Step Constructions Limited | Construction | 2024 |
| One Stop Secure Ltd | Information & communication | 2023 |
| One Telecom Group Ltd | Information & communication | 2024 |
| Onecloud PVT Ltd | Wholesale & retail | 2026 |
| Onehub Solution Ltd | Wholesale & retail | 2026 |
| Onesello Ltd | Wholesale & retail | 2025 |
| Onesixfive Right to Manage Company Limited | Households | 2026 |
| Onicor Ltd | Construction | 2023 |
| Online Crowd Ltd | Wholesale & retail | 2020 |
| Online Digi Solutions Ltd | Information & communication | 2025 |
| Online EV Limited | Wholesale & retail | 2021 |
| Online Property Solutions Ltd | Real estate | 2020 |
| Onniex Services Limited | Administrative & support | 2020 |
| Onofrei Construction Ltd | Construction | 2026 |
| Onsite Property Maintenance and Services Limited | Construction | 2023 |
| Ontime Cargo Limited | Administrative & support | 2017 |
| Onward Travels Ltd | Transport & logistics | 2026 |
| Onyx Ventures Ltd | Real estate | 2026 |
| Openparcel Store Ltd | Wholesale & retail | 2023 |
| Ophthalmic Experts Limited | Health & social care | 2009 |
| Opoku Construction Limited | Construction | 2020 |
| Optilife Healthcare Ltd | Manufacturing | 2023 |
| Optimax DWC Limited | Real estate | 2023 |
| Optimum Care (GL) Limited | Administrative & support | 2018 |
| Optimum Energy Brokers Ltd | Energy | 2020 |
| Optimum Enterprises Ltd | Real estate | 2025 |
| Opulence Jewellery Services Ltd | Wholesale & retail | 2025 |
| Oracle Safety Systems Ltd | Wholesale & retail | 2026 |
| Orange and Lemon Barking Limited | Education | 2018 |
| Orange Thai Ltd | Hospitality | 2025 |
| Orbit Staff Solutions Ltd | Administrative & support | 2024 |
| Orbita Cloud Limited | Information & communication | 2023 |
| Orchard Stays Limited | Real estate | 2025 |
| Orchestra AI Ltd | Information & communication | 2026 |
| Orchid Sky Ltd | Administrative & support | 2025 |
| Orega Consultancy Services Ltd | Other services | 2023 |
| Oreon 22 Limited | Other services | 2010 |
| Organic Dynamic Ltd | Information & communication | 2022 |
| Organic Tours and Travel Ltd | Other services | 2019 |
| Orgito&Albion Accounting Ltd | Professional & scientific | 2021 |
| Orient Architectural Systems Ltd | Manufacturing | 2023 |
| Orient Real Estates Limited | Real estate | 2015 |
| Oriental Essential Limited | Wholesale & retail | 2018 |
| Origin Mart Ltd | Administrative & support | 2016 |
| Orizon Group Ltd | Information & communication | 2026 |
| Orizona Consulting and Logistics Limited | Wholesale & retail | 2024 |
| Orka Banyo UK Limited | Wholesale & retail | 2026 |
| Orki Ltd | Wholesale & retail | 2023 |
| Orpearl Limited | Health & social care | 2020 |
| Orrivo Security Ltd | Administrative & support | 2025 |
| Orveos Group Ltd | Transport & logistics | 2024 |
| Orwell Law Limited | Professional & scientific | 2017 |
| OSI Inc. Ltd | Health & social care | 2018 |
| Osis Group Limited | Construction | 2018 |
| Oskway Ltd Ltd | Construction | 2019 |
| Osmarson Development Limited | Real estate | 2024 |
| Osmarson Property Limited | Real estate | 2024 |
| Osulio Limited | Construction | 2025 |
| Osvald Transport Limited | Transport & logistics | 2021 |