| Orderstone Limited | Information & communication | 2026 |
| Ordertown L.P. | | 2015 |
| Ordino Ltd | Information & communication | 2018 |
| Ordoss Trading LP | | 2014 |
| ORE Functional Ltd | Wholesale & retail | 2026 |
| Oregon Capital LP | | 2014 |
| Oreo Tech Ltd | Information & communication | 2026 |
| Organic Cosmetics Limited | Professional & scientific | 2012 |
| Organic Nourishment Ltd | Wholesale & retail | 2025 |
| Organic Principles Limited | Manufacturing | 2020 |
| Organik Prod LP | | 2025 |
| Organised Chaos Edinburgh Ltd | Households | 2020 |
| Organo Investments LP | | 2016 |
| Orgserve Consultancy Services Limited | Information & communication | 2020 |
| Orient Assets L.P. | | 2010 |
| Orient Bay Ltd | Real estate | 2026 |
| Orient Bend LP | | 2012 |
| Orient Developments Corporation L.P. | | 2010 |
| Orient Global Services L.P. | | 2011 |
| Orient Impex LP | | 2011 |
| Orient Import/Export L.P. | | 2012 |
| Orient Invest LP | | 2015 |
| Orient Logistic LP | | 2016 |
| Orient Luck LP | | 2016 |
| Orient Projects L.P. | | 2012 |
| Orient Travel Services LP | | 2016 |
| Oriental Export Group LP | | 2014 |
| Oriental Food Edinburgh Ltd | Hospitality | 2023 |
| Oriental Technology UK Limited | Wholesale & retail | 2023 |
| Oriento Limited | Hospitality | 2019 |
| Origin Distribution LP | | 2014 |
| Origin Fitness Limited | Wholesale & retail | 2008 |
| Origin Trading Services Limited | Information & communication | 2008 |
| Original Angle Limited | Information & communication | 2024 |
| Original Casuals Ltd | Wholesale & retail | 2012 |
| Original Classic Cars LP | | 2012 |
| Original World LP | | 2017 |
| Origins Retreats Ltd | Education | 2023 |
| Origo Secure Internet Services Limited | Information & communication | 1999 |
| Origo Services Limited | Information & communication | 1988 |
| Origo Seven Ltd | Other services | 2025 |
| Orika Flow Ltd | Information & communication | 2026 |
| Orinet LP | | 2016 |
| Oringer Services LP | | 2019 |
| Orinoco Investments L.P. | | 2015 |
| Orinoko Export LP | | 2013 |
| Orinsen Limited | Real estate | 2019 |
| Orion Capital Technologies Ltd | Information & communication | 2026 |
| Orion Care (Edinburgh) Limited | Health & social care | 2010 |
| Orion Construction L.P. | | 2011 |
| Orion International L.P. | | 2008 |
| Orion Ventures Limited | Real estate | 2018 |
| Orix Trade LP | | 2016 |
| Orizona LP | | 2015 |
| ORK Capital LP | | 2017 |
| Orka Sauna Limited | Health & social care | 2025 |
| Orkney Alliance LP | | 2015 |
| Orkney Hydrogen Trading Ltd | Wholesale & retail | 2015 |
| Orkney Trast LP | | 2013 |
| Orlamber Ltd | Professional & scientific | 2022 |
| Orlando Alliance LP | | 2016 |
| Orlando Italiano Ltd | Hospitality | 2023 |
| Orleana LP | | 2014 |
| Orli (Scotland) Limited | Manufacturing | 2014 |
| Orlita Invest LP | | 2016 |
| Orlo Energy Ltd | Professional & scientific | 2002 |
| Orlock Advisors Limited | Professional & scientific | 2009 |
| Ormanbay Management LP | | 2015 |
| Ormant Universal LP | | 2012 |
| Ormanton Global LP | | 2014 |
| Ormanville Solutions LP | | 2015 |
| Ormidale Investments Ltd | Financial services | 2026 |
| Ormiston Capital LP | | 2014 |
| Ormiston Quest LP | | 2017 |
| Ormiston Union LP | | 2014 |
| Ormond Import/Export L.P. | | 2011 |
| Ormond Industrial L.P. | | 2011 |
| Ormond Partnership LP | | 2009 |
| Ormus Ltd | Wholesale & retail | 2022 |
| Ornella Management & Consulting LP | | 2015 |
| Orneto Partners LP | | 2020 |
| Orono Solutions LP | | 2015 |
| Oronsay Property Ltd | Real estate | 2025 |
| Orotox Business LP | | 2016 |
| Orounda Finance LP | | 2015 |
| Orpheus Corp. Technology L.P. | | 2014 |
| Orpheus Global L.P. | | 2009 |
| Orpheus Taverna Ltd | Hospitality | 2026 |
| Orphix Limited | Wholesale & retail | 2026 |
| Orquidea LP | | 2003 |
| ORR Squared Limited | Professional & scientific | 2021 |
| Orreola LP | | 2015 |
| Orrmac (NO 50) Limited | Professional & scientific | 1986 |
| Orrmac (NO:500) Limited | Real estate | 1991 |
| Orrmac (NO:810) Limited | Real estate | 1997 |
| Orroland Ltd | Real estate | 2023 |
| Orry Offices Ltd | Administrative & support | 2025 |
| Orsid Investment Company | | 2003 |
| Orsted Falcon Limited | Administrative & support | 2022 |
| Orsted Scotland Renewables Holdco 2 Limited | Administrative & support | 2021 |