| North Ronaldsay Trading Company Limited | Hospitality | 2005 |
| Northern Turbine Services Limited | Manufacturing | 2015 |
| Northvet Holdings Limited | Financial services | 2019 |
| Northvet Veterinary Group Limited | Professional & scientific | 2014 |
| NS Deyanov Ltd | Health & social care | 2014 |
| Old Library Coworking Ltd | Real estate | 2021 |
| ON2H Limited | Financial services | 2025 |
| Orbital Marine Power (Orkney) PLC | Energy | 2018 |
| Orbital Marine Power Limited | Administrative & support | 2002 |
| Orbital Projects (Holdings) Limited | Energy | 2021 |
| Orbital Projects 1 Limited | Energy | 2021 |
| Orbital Projects 10 Limited | Energy | 2024 |
| Orbital Projects 11 Limited | Energy | 2024 |
| Orbital Projects 2 Limited | Energy | 2021 |
| Orbital Projects 3 Limited | Energy | 2021 |
| Orbital Projects 4 Limited | Energy | 2021 |
| Orbital Projects 5 Limited | Energy | 2022 |
| Orbital Projects 6 Limited | Energy | 2022 |
| Orbital Projects 7 Limited | Energy | 2023 |
| Orbital Projects 8 Limited | Energy | 2023 |
| Orbital Projects 9 Limited | Energy | 2023 |
| Orcades Hostel Limited | Hospitality | 2023 |
| Orcades Marine Management Consultants Ltd | Professional & scientific | 2010 |
| Orcadian Limited the | Extraterritorial | 1987 |
| Orkadia Esports Ltd | Arts & recreation | 2025 |
| Orkfab Ltd | Manufacturing | 2013 |
| Orklean Ltd | Administrative & support | 2019 |
| Orkney 2025 | Arts & recreation | 2018 |
| Orkney Aggregates Limited | Mining & quarrying | 1999 |
| Orkney Builders (Contractors) Limited | Construction | 1998 |
| Orkney Builders Limited | Real estate | 1944 |
| Orkney Business Consultants Ltd | Professional & scientific | 2020 |
| Orkney Business Ring - Labour Agency Limited | Administrative & support | 2006 |
| Orkney Cabs Ltd | Transport & logistics | 2026 |
| Orkney CBD Ltd. | Agriculture & fishing | 2024 |
| Orkney Chalets Limited | Hospitality | 2017 |
| Orkney Cheese Company Limited | Manufacturing | 1999 |
| Orkney Citizens Advice Bureau | Other services | 1997 |
| Orkney Community Transport Organisation Community Interest Company | Transport & logistics | 2008 |
| Orkney Computer Specialists Ltd | Other services | 2016 |
| Orkney Cowl Company Limited | Wholesale & retail | 2016 |
| Orkney Disability Forum | Transport & logistics | 1997 |
| Orkney Distilling Limited | Manufacturing | 2016 |
| Orkney Driving Academy Ltd | Education | 2022 |
| Orkney Factors Limited | Wholesale & retail | 1971 |
| Orkney Food and Drink | Administrative & support | 1993 |
| Orkney Golf Club Ltd | Arts & recreation | 2014 |
| Orkney Goose Ltd | Wholesale & retail | 2024 |
| Orkney Harbour Holidays Ltd | Hospitality | 2025 |
| Orkney Homes Trust Limited | Real estate | 1991 |
| Orkney Hospitality Ltd | Hospitality | 2026 |
| Orkney Inflatables Ltd | Administrative & support | 2019 |
| Orkney Inspections Ltd | Professional & scientific | 2025 |
| Orkney Insurance Brokers Ltd | Financial services | 2023 |
| Orkney Islands Property Developments Limited | Real estate | 1991 |
| Orkney Marinas Limited | Transport & logistics | 2001 |
| Orkney Marine OIL Company Limited | Wholesale & retail | 2004 |
| Orkney Mechanical Services Limited | Construction | 1999 |
| Orkney Media Group Limited | Manufacturing | 2007 |
| Orkney Micro-Renewables C.I.C. | Professional & scientific | 2011 |
| Orkney Multiple Sclerosis Therapy Centre Ltd. | Health & social care | 1989 |
| Orkney Nature Ltd | Information & communication | 2015 |
| Orkney Office Supplies Limited | Manufacturing | 1989 |
| Orkney Quality Developments Limited | Real estate | 1997 |
| Orkney Renewables Limited | Construction | 2011 |
| Orkney RFC Trading Co Ltd | Arts & recreation | 2025 |
| Orkney Riding Centre | Arts & recreation | 2010 |
| Orkney Rose Limited | Wholesale & retail | 2006 |
| Orkney Rugby Football Club Ltd | Arts & recreation | 2024 |
| Orkney Scallops Ltd | Agriculture & fishing | 2019 |
| Orkney Soap Limited | Manufacturing | 2020 |
| Orkney Stays Limited | Real estate | 2025 |
| Orkney Sustainable Energy Limited | Professional & scientific | 1995 |
| Orkney Taxis and Private Hire Ltd | Transport & logistics | 2021 |
| Orkney Taxis Ltd | Transport & logistics | 2018 |
| Orkney Time Travel Ltd | Administrative & support | 2026 |
| Orkney Today Limited | Extraterritorial | 2003 |
| Orkney Travel Ltd | Transport & logistics | 2022 |
| Orkney Vintage Club | Other services | 2003 |
| Orkney Wireless Museum | Arts & recreation | 2005 |
| Orkney Youth Cafe | Other services | 2009 |
| Orkney Zerowaste | Water & waste | 2005 |
| Orkneytech Ltd | Wholesale & retail | 2016 |
| Ortak Limited | Manufacturing | 2014 |
| Ortak Retail (Inverness) Ltd | Wholesale & retail | 2021 |
| Ortak Retail (Stornoway) Ltd | Wholesale & retail | 2021 |
| P T H Fishing Ltd. | Agriculture & fishing | 2005 |
| Palace Enterprise (Scotland) Limited | Administrative & support | 2008 |
| Papdale Stores | Wholesale & retail | 2019 |
| Patrick Mcgrath Ltd | Professional & scientific | 2014 |
| PD Construction (Orkney) Ltd | Construction | 2021 |
| Pearl Vista Limited | Hospitality | 2011 |
| Peedie Cabs Ltd | Transport & logistics | 2019 |
| Peedie Dragon Ltd | Arts & recreation | 2023 |
| Peedie Sea Distilling Limited | Manufacturing | 2018 |
| Pipedream Plumbing Ltd | Construction | 2013 |
| Pixel Insight Limited | Professional & scientific | 2017 |
| Polaris Energy Ltd | Professional & scientific | 2024 |
| Port Raasay Limited | Information & communication | 2023 |
| Quanterness Ltd | Financial services | 2025 |