| Oscar Blackford Limited | Professional & scientific | 1940 |
| Oscar Reed Limited | Wholesale & retail | 2024 |
| Osprey Analytics Ltd | Other services | 2022 |
| OTR Carpentry & Construction Ltd | Construction | 2023 |
| OTS Falmouth (Holdings) Ltd | Transport & logistics | 2024 |
| Otter Surfboards Limited | Manufacturing | 2010 |
| OTW Group Ltd | Financial services | 2026 |
| OTW Holdings Ltd | Real estate | 2014 |
| OUT of Wood Limited | Manufacturing | 2001 |
| Outcomes Engine Ltd | Information & communication | 2024 |
| Outdoor Survival Limited | Wholesale & retail | 2025 |
| Outfox the Box Ltd | Manufacturing | 2017 |
| Outreach & Education Ltd | Other services | 2017 |
| Outwit Holdings LP | | 2020 |
| Owen Clarke Design Limited Liability Partnership | | 2002 |
| Own Ventures Ltd | Wholesale & retail | 2026 |
| Oxley Bros Limited | Wholesale & retail | 2023 |
| P & a Mitchell Limited | Construction | 2002 |
| P & S MAY Limited | Administrative & support | 2017 |
| P Abraham & SON Limited | Wholesale & retail | 2003 |
| P Chapman Construction Limited | Construction | 2010 |
| P M B Estates Limited | Real estate | 2003 |
| P Perryman & Sons Limited | Wholesale & retail | 2003 |
| P R Weldhen Developments Limited | Construction | 2014 |
| P. a. V. H. International Limited | Professional & scientific | 1976 |
| PAC Contractors Ltd | Construction | 2025 |
| Packedge Ltd | Professional & scientific | 2012 |
| Paddle & Cocks LLP | | 2017 |
| Palmer Fabrications Ltd | Manufacturing | 2019 |
| Palmgray Ltd | Health & social care | 2022 |
| Parade Properties (Newquay) Limited | Real estate | 1962 |
| Paradhis Limited | Arts & recreation | 2024 |
| Paradise Park Limited | Professional & scientific | 1970 |
| Paradox IP Limited | Professional & scientific | 2026 |
| Paragon Investment Capital Ltd | Financial services | 2014 |
| Parcert Limited | Wholesale & retail | 2019 |
| Park an Daras Management Company Ltd | Households | 2018 |
| Park Bottom Management Company Limited | Households | 2016 |
| Park Electrical Installations Ltd | Construction | 2011 |
| Park House Ventures Limited | Information & communication | 2013 |
| Park Lane Financial Management Ltd | Financial services | 2013 |
| Park Rosmoren Management Company Limited | Households | 2017 |
| Park Trielin Management Company Limited | Real estate | 2017 |
| Parker Developments CV1 Limited | Real estate | 2024 |
| Parkers Commercials Limited | Wholesale & retail | 2013 |
| Parkfish Properties Ltd | Hospitality | 2019 |
| Parking Spaces at Albert Place Management Company Limited | Households | 2020 |
| Parkland Group Limited | Professional & scientific | 2006 |
| Parsons Property Investments Ltd | Real estate | 2018 |
| Participa Cornwall CIC | Health & social care | 2023 |
| Pasco's Boatyard Limited | Manufacturing | 2009 |
| Paterson & Cooke (UK) Ltd. | Mining & quarrying | 2013 |
| Paterson & Cooke Europe Ltd | Financial services | 2021 |
| Paterson & Cooke Group Limited | Administrative & support | 2007 |
| Path 11 Ltd | Professional & scientific | 2026 |
| Path Integral Ltd | Professional & scientific | 2024 |
| Pathfinders Mentoring CIC | Education | 2024 |
| Pathos Entertainment Ltd | Information & communication | 2021 |
| Patrol Systems Limited | Information & communication | 2023 |
| Patwardhan Ophthalmology Limited | Health & social care | 2011 |
| Paul Grey Financial Planning Ltd | Financial services | 2017 |
| Paul Mitchell Sacks Limited | Manufacturing | 2015 |
| Paul Morgan and Associates Wealth Management Ltd | Financial services | 2018 |
| Paul Rabey Plumbing and Heating Limited | Construction | 2016 |
| Payline Limited | Professional & scientific | 1987 |
| Payne Media UK Ltd | Professional & scientific | 2026 |
| Payon Accounting Ltd | Professional & scientific | 2025 |
| PB 11 INT Limited | Wholesale & retail | 2026 |
| Pb&Fc LLP | | 2024 |
| PC Cargo (UK) Ltd. | Administrative & support | 2012 |
| PC Holdings (SW) Limited | Financial services | 2016 |
| PC Properties (SW) Limited | Households | 2016 |
| PCB Properties Ltd | Real estate | 2022 |
| PCC Capital Ltd | Financial services | 2026 |
| PCC Development SW Ltd | Construction | 2026 |
| PCM Real Estate Limited | Construction | 2023 |
| PCS Gilbert Services Ltd | Wholesale & retail | 2026 |
| PD Investment Services Ltd | Real estate | 2026 |
| PD Locum Dental Services Ltd | Health & social care | 2026 |
| Pdht (SUB) Limited | Extraterritorial | 2019 |
| Pdht Limited | Health & social care | 2019 |
| Pdsvale (UK) Limited | Mining & quarrying | 2005 |
| Peacocks Conversions and Renovations Ltd | Construction | 2024 |
| Peacocks Kitchens and Interiors Ltd | Manufacturing | 2025 |
| Peak Road Freeholds Limited | Households | 2006 |
| Pearce Developments Ltd | Construction | 2017 |
| Peat House Limited | Extraterritorial | 2018 |
| PEG Management and Consultancy Ltd | Professional & scientific | 2025 |
| Pegasus Motorcycles Limited | Wholesale & retail | 2005 |
| Pellows Transport Ltd | Transport & logistics | 2021 |
| Pellows Waste Disposal Services Ltd | Water & waste | 1997 |
| PEM NOM Limited | Administrative & support | 2011 |
| Penair School | Education | 2011 |
| Penbeagle Property Management Company Limited | Households | 2022 |
| Penbreage Design Services Ltd | Construction | 2019 |
| Pencarrow Properties Limited | Financial services | 2000 |
| Pendarren Limited | Professional & scientific | 2017 |
| Pendarves Homes Ltd | Construction | 2020 |
| Pendennis Court Limited | Households | 2009 |
| Pendennis House Ltd | Health & social care | 2015 |