| Nycnix Limited | Information & communication | 2013 |
| Nyctaeus Limited | Wholesale & retail | 2026 |
| Nyde Studio Ltd | Professional & scientific | 2020 |
| NYE Director Limited | Administrative & support | 2025 |
| Nylcap Mezzanine Offshore Iii-S, LP | | 2012 |
| Nylcap Mezzanine Offshore Partners Iii-S, LP | | 2012 |
| Nymtel Express LP | | 2015 |
| NYN Management Ltd | Professional & scientific | 2026 |
| NYN Traders Ltd | Wholesale & retail | 2026 |
| Nysa Properties Ltd | Real estate | 2023 |
| Nyumba Yanga Ltd | Real estate | 2020 |
| NYZ Group Ltd | Wholesale & retail | 2026 |
| NZP1027 Ltd | Professional & scientific | 2023 |
| O Chocolates Ltd | Wholesale & retail | 2023 |
| O M Holdings Ltd | Financial services | 2020 |
| O Markaz Ltd | Wholesale & retail | 2024 |
| O&A Sparkle Solutions Ltd | Administrative & support | 2024 |
| O&O Cleaning Ltd | Professional & scientific | 2026 |
| O&O Properties Limited | Real estate | 2016 |
| O' GEM Trading LP | | 2011 |
| O'Brien HR Ltd | Administrative & support | 2024 |
| O'Neill & Goldie (Masonry) Ltd | Other services | 2015 |
| O'Neill Defence Ltd | Professional & scientific | 2022 |
| O'Neill's Property Limited | Real estate | 2001 |
| O'Tutu & Associates Limited | Professional & scientific | 2015 |
| O-Sona Limited | Wholesale & retail | 2026 |
| O.G. Apartments Ltd | Real estate | 2020 |
| O.R. Plumbing & Heating Ltd | Construction | 2023 |
| O.R.B Enterprises Ltd | Wholesale & retail | 2018 |
| O.S Property Care Ltd | Households | 2025 |
| O2IDEAS LP | | 2015 |
| Oaef Carry LP | | 2025 |
| Oak & Black Ltd | Manufacturing | 2020 |
| Oak & Desert LP | | 2004 |
| Oak and Elixir Limited | Wholesale & retail | 2023 |
| Oak and IVY Education Services Ltd | Education | 2025 |
| Oak and IVY Garden Solutions Ltd | Administrative & support | 2026 |
| Oak Bank Developments Limited | Real estate | 1999 |
| Oak Building & Maintenance Ltd | Construction | 2026 |
| Oak Forestry Ltd | Agriculture & fishing | 2019 |
| Oak Investments LP | | 2005 |
| Oak Noir Design Ltd | Wholesale & retail | 2025 |
| Oak Tree VET Centre Limited | Extraterritorial | 2012 |
| Oakbank Asset Management Limited | Administrative & support | 2012 |
| Oakbank Products Limited | Manufacturing | 2013 |
| Oakbank Property Limited | Construction | 2017 |
| Oakbank WAX Ltd | Manufacturing | 2020 |
| Oakdale Import/Export L.P. | | 2010 |
| Oakferry Industries LP | | 2014 |
| Oakfield Chiropractic Ltd | Health & social care | 2020 |
| Oakfield Consulting LP | | 2013 |
| Oakhill (Scotland) Limited | Construction | 1999 |
| Oakhill Software Solutions LP | | 2015 |
| Oakhurst Consultancy (Scotland) Ltd | Professional & scientific | 2018 |
| Oakley Capital Scotland L.P. | | 2007 |
| Oaklife Ltd | Other services | 2026 |
| Oakmont High Reach Window Cleaning Ltd | Administrative & support | 2019 |
| Oakridge (Edgehead) Limited | Construction | 2014 |
| Oakridge (Glenmavis) Limited | Construction | 2016 |
| Oakridge (Group) Limited | Real estate | 2010 |
| Oakridge (Village) Limited | Real estate | 2017 |
| Oakridge Homes Limited | Construction | 2012 |
| Oakridge Ltd | Professional & scientific | 2023 |
| Oakridge Property Limited | Construction | 2005 |
| Oakvale Assets L.P. | | 2011 |
| Oakvale Investments L.P. | | 2008 |
| Oakwood Advisory Limited | Professional & scientific | 2025 |
| Oakwood Nurseries Limited | Education | 2001 |
| Oasis Alliance LP | | 2015 |
| Oasis Club Ltd | Professional & scientific | 2025 |
| Oasis Syndicate LP | | 2016 |
| Oasis Universal LP | | 2015 |
| Oath Fitness Limited | Arts & recreation | 2025 |
| Oatsworth LP | | 2015 |
| Oaxaca Scots L.P. | | 2011 |
| OB Motorworks Ltd | Wholesale & retail | 2026 |
| OBA Dent Ltd | Health & social care | 2024 |
| Obadiah Coffee Ltd | Manufacturing | 2020 |
| Obaid Essentials Hub Limited | Wholesale & retail | 2025 |
| Oban Kids Thrive CIC | Wholesale & retail | 2026 |
| Obando Invest LP | | 2015 |
| OBC Way LP | | 2016 |
| Obelus Limited | Real estate | 2023 |
| Oberlanders Architects LLP | | 2005 |
| Oberlanders Group LLP | | 2022 |
| Oberlanders Property LLP | | 2007 |
| Oberlanders Trustees Limited | Professional & scientific | 2008 |
| Oberoy LP | | 2012 |
| Obilie Group LP | | 2017 |
| Obilinkz Ltd | Wholesale & retail | 2025 |
| Obirnex LP | | 2017 |
| Objective (Scotland) Limited | Professional & scientific | 2008 |
| Objexs Limited | Information & communication | 2017 |
| Oblak Limited | Professional & scientific | 2010 |
| Oblik Group LP | | 2018 |
| Obluse Corporation LP | | 2013 |
| OBO Technologies LP | | 2015 |
| Obobo Ltd | Information & communication | 2025 |
| Obraich Limited | Professional & scientific | 2023 |
| Obrigado PK Ltd | Professional & scientific | 2023 |