| Obroc General Partner Limited | Administrative & support | 2014 |
| Obroc Limited Partnership | | 2014 |
| OBS 2009 | | 2008 |
| OBS 2010 LP | | 2009 |
| OBS 2011 LP | | 2010 |
| Obscurion Talent Ltd | Information & communication | 2025 |
| Obsearth Limited | Information & communication | 2019 |
| Observes IO Ltd | Information & communication | 2025 |
| Obsidian Arts Limited | Wholesale & retail | 2024 |
| Obsidian Biotech Limited | Other services | 2026 |
| Obsidian Systems & Consulting Ltd | Wholesale & retail | 2026 |
| Obtp Group LP | | 2017 |
| Obuqot Dynamics Int’L Limited | Administrative & support | 2025 |
| Obvlo Limited | Information & communication | 2018 |
| OC I Scotco Limited | Financial services | 2024 |
| OC Social Club Ltd | Professional & scientific | 2020 |
| OCA Horizon LP | | 2022 |
| Ocanom (Holdings) Ltd | Financial services | 2020 |
| Occam Solutions Ltd | Professional & scientific | 2023 |
| Occasio Capital Ltd | Information & communication | 2019 |
| Occasional Rain Ltd | Professional & scientific | 2024 |
| Occhi D’Oro Ltd | Manufacturing | 2025 |
| Occupancy Marketing Limited | Information & communication | 2009 |
| Occupira Ltd | Real estate | 2025 |
| Ocean Atlantic Partners LP | | 2018 |
| Ocean Bar Edinburgh Ltd | Hospitality | 2024 |
| Ocean Biofuels Ltd | Information & communication | 2021 |
| Ocean Clinics Holdings Ltd | Health & social care | 2026 |
| Ocean Commercial Services L.P. | | 2011 |
| Ocean Cooling Technology Limited | Professional & scientific | 2003 |
| Ocean Drive Clinic Ltd | Health & social care | 2026 |
| Ocean Energy Scotland Limited | Manufacturing | 2017 |
| Ocean Energy TEC Ltd | Professional & scientific | 2023 |
| Ocean Industries L.P. | | 2012 |
| Ocean Instruments Ltd | Wholesale & retail | 2007 |
| Ocean Mind Concepts LP | | 2025 |
| Ocean Nails & Spa Limited | Other services | 2024 |
| Ocean Orthodontic Clinic Ltd | Health & social care | 2024 |
| Ocean Pours Creations Ltd | Arts & recreation | 2025 |
| Ocean Projects Worldwide L.P. | | 2012 |
| Ocean RAY Consulting Limited | Administrative & support | 2019 |
| Ocean Services Worldwide L.P. | | 2011 |
| Ocean Sky Innovius LP | | 2017 |
| Ocean Star Management LP | | 2016 |
| Oceanbay Marine LP | | 2011 |
| Oceandots Logistics Limited | Wholesale & retail | 2025 |
| Oceania Gate Ltd | Wholesale & retail | 2025 |
| Oceanic Energy Ltd | Construction | 2024 |
| Oceanic Palace Holdings LP | | 2016 |
| Oceanic Systems Digital Twins Ltd | Information & communication | 2025 |
| Oceanica Azure LP | | 2017 |
| Oceans Cafe Edinburgh Ltd | Hospitality | 2022 |
| Oceansense Ltd | Professional & scientific | 2019 |
| Oceanstar Tidal Ltd | Professional & scientific | 2023 |
| Oceanteam Power & Umbilical Limited | Professional & scientific | 2005 |
| Oceanview Enterprises L.P. | | 2012 |
| OCH AYE DA MOO Limited | Wholesale & retail | 2025 |
| OCH VEY CIC | Arts & recreation | 2026 |
| Ochil Fencing & Maintenance Ltd | Construction | 2026 |
| Ochil Tower Co-Worker Retirement Trust Limited | Financial services | 2004 |
| Ochill View Dental Implant Laboratory Limited | Health & social care | 2014 |
| Ochiltree Joinery Scotland Limited | Construction | 2019 |
| Ochlochy Investments Limited | Real estate | 2017 |
| Ochun Ltd | Health & social care | 2019 |
| Ociosozy Ltd | Administrative & support | 2024 |
| Ociovium Ltd | Administrative & support | 2024 |
| Oclion Inter LP | | 2013 |
| OCM (Hfls) Limited | Financial services | 2024 |
| OCM Services Ltd | Administrative & support | 2021 |
| OCO Livingston Limited | Wholesale & retail | 2005 |
| OCO Sports Group Ltd | Professional & scientific | 2026 |
| OCS Property/Rentals Ltd | Real estate | 2025 |
| Octagon Consulting Ltd | Professional & scientific | 2015 |
| Octagon Trading Limited | Real estate | 1987 |
| Octamedia Group Limited | Professional & scientific | 2019 |
| Octane Audio Limited | Manufacturing | 2011 |
| Octangle Beauty Ltd | Other services | 2018 |
| Octant Investments Limited | Construction | 2008 |
| Octava Trading LP | | 2014 |
| Octavo Property Limited | Real estate | 2023 |
| Octi Investments Ltd | Financial services | 2026 |
| Octi-Nutrition Ltd | Wholesale & retail | 2025 |
| Octmedia LP | | 2016 |
| Octo Capital Investements (UK) Ltd | Professional & scientific | 2024 |
| Octo Capital LP | | 2019 |
| Octo Group Limited | Wholesale & retail | 1976 |
| October Forth Limited | Professional & scientific | 2017 |
| October Investments Ltd. | Real estate | 1986 |
| Octocore Corporation LP | | 2015 |
| Octocrowd Limited | Arts & recreation | 2018 |
| Octopi Developments Ltd | Construction | 2025 |
| Octopi Research Labs (UK) Limited | Administrative & support | 2017 |
| Octopus Affordable Housing Scottish GP LLP | | 2025 |
| Octopus Athena I FP GP LLP | | 2021 |
| Octopus Athena I FP L.P. | | 2021 |
| Octopus CFE Founder Partner L.P. | | 2009 |
| Octopus First Cheque I FP GP LLP | | 2021 |
| Octopus First Cheque I FP LP | | 2021 |
| Octopus First Cheque II FP GP LLP | | 2022 |
| Octopus First Cheque II FP LP | | 2022 |