| NO Farmers NO Food Ltd | Professional & scientific | 2024 |
| Noble Kernow Limited | Administrative & support | 2016 |
| Nordic Kayaks UK Ltd | Wholesale & retail | 2021 |
| North Coast Holiday Cottages Ltd | Hospitality | 2017 |
| North Coast Plumbing & Heating Ltd | Construction | 2019 |
| North Country Garage Ltd | Wholesale & retail | 2010 |
| North Orchard Court (Goldsithney) Residents Association Limited | Households | 1992 |
| Norway Square Management Company Limited | Real estate | 2006 |
| NP & CP Dunstan Builders Limited | Construction | 2022 |
| NPA Carpentry and Construction Ltd | Construction | 2024 |
| NPA Carpentry Ltd | Manufacturing | 2018 |
| Oak Park (ST. Tudy) Limited | Real estate | 1999 |
| Oakburn Villa Management Limited | Real estate | 1989 |
| Oakes Drafting Services Limited | Construction | 2008 |
| Oakeyoakstores Ltd | Wholesale & retail | 2022 |
| Occupational Health South West Limited | Health & social care | 2009 |
| Ocean Hydraulics (UK) Limited | Professional & scientific | 2012 |
| Oceanperf UK Limited | Wholesale & retail | 2021 |
| ODM Electrical Ltd | Construction | 2023 |
| Officesmart South West Limited | Wholesale & retail | 2003 |
| Offshore Marine Solutions Limited | Transport & logistics | 2004 |
| Ohmsure Ltd | Information & communication | 2026 |
| OMC (UK) Holdings Limited | Financial services | 2020 |
| ON Site Framing Ltd | Construction | 2009 |
| Online Business KIT Ltd | Information & communication | 2026 |
| Onscreen Magazine Limited | Information & communication | 2014 |
| Opal and ORA Ltd | Administrative & support | 2026 |
| Opie Oils Limited | Wholesale & retail | 1994 |
| Orange Flamingo Events Ltd | Hospitality | 2021 |
| Orbis International Ltd | Transport & logistics | 2016 |
| Orchard Housing Developments Ltd | Extraterritorial | 2011 |
| Orchard Housing Ltd | Real estate | 2008 |
| Origin Double Glazing Ltd | Construction | 2025 |
| OUT of the Box Play and Creative Arts Therapy Ltd | Education | 2018 |
| OUT of the Ordinary Events Limited | Administrative & support | 2017 |
| OUT of the Woods Play and Creative Arts Therapy CIC | Health & social care | 2021 |
| Outlawas Ltd | Manufacturing | 2023 |
| OWJ Finance Limited | Financial services | 2025 |
| Oyster Consultancy Ltd | Other services | 2023 |
| P & L Transfer Limited | Transport & logistics | 2003 |
| P Tonkin Surfacing Ltd | Construction | 2020 |
| P Ventilation Ltd | Extraterritorial | 2023 |
| P&S Heath Limited | Information & communication | 2025 |
| Padstow Harbour Bakery Ltd | Real estate | 2022 |
| Palm Court Flats (Truro) Limited | Households | 1992 |
| Pangolin Properties Ltd | Real estate | 2025 |
| Paragon Response Limited | Other services | 1994 |
| Partridge Project Services Ltd | Construction | 2026 |
| Partridge Ventilation Limited | Manufacturing | 2019 |
| Partridge Ventilation Service and Maintenance Limited | Administrative & support | 2010 |
| Patrick Burke Mental Health Ltd | Health & social care | 2026 |
| Pattern Cameras Ltd | Wholesale & retail | 2025 |
| Paul Mitchell Property Co. Limited | Construction | 2004 |
| PD Aero Services Ltd | Manufacturing | 2016 |
| Peakes of Tolcarne Limited | Other services | 2011 |
| Pebbledash Cornwall Ltd | Construction | 2020 |
| Pegasus - Men's Wellbeing Centre Community Interest Company | Other services | 2014 |
| Pelican Psychiatry Ltd | Health & social care | 2025 |
| Pellow Roofing Ltd | Construction | 2018 |
| Pellyn Downs Management Company Limited | Households | 2022 |
| PEN Three Ltd | Financial services | 2021 |
| Penberthy Court Management Company Limited | Administrative & support | 2003 |
| Pencoys Properties Ltd | Real estate | 2021 |
| Pendennis M.C. & L.C.C. Limited | Arts & recreation | 2005 |
| Pendower Court Residents Association Limited | Households | 1999 |
| Pendriggy Holdings Limited | Financial services | 2024 |
| Pendriggy Limited | Real estate | 2024 |
| Pendynas Limited | Education | 2018 |
| Penelope Weinreb Ltd | Health & social care | 2022 |
| Pengoon Farm Ltd | Agriculture & fishing | 2024 |
| Penhaligon Brothers Limited | Extraterritorial | 2021 |
| Penhallow Geothermal Limited | Construction | 2024 |
| Penhalurick Barton Limited | Extraterritorial | 1997 |
| Peninsula Education Ltd. | Education | 2019 |
| Peninsula Fuels Ltd | Wholesale & retail | 2017 |
| Peninsula Mortgages Ltd | Financial services | 2021 |
| Penlee Family Project CIC | Education | 2010 |
| Penmara Holdings Properties Limited | Financial services | 2024 |
| Penmara Properties Limited | Real estate | 2024 |
| Penpol Properties Limited | Real estate | 2000 |
| Penreen Management Company Limited | Households | 2008 |
| Penrose Camping and Leisure Limited | Wholesale & retail | 1978 |
| Penrose House (Camborne) Management Company Limited | Households | 2016 |
| Penventon Holdings Limited | Financial services | 2017 |
| Penventon Hotel (1970) Limited | Hospitality | 1970 |
| Penventon Property Company Limited | Construction | 2017 |
| Percy Wigg Limited | Wholesale & retail | 2017 |
| Perkins & Perry Group Limited | Financial services | 2024 |
| Perkins & Perry Ltd. | Construction | 2000 |
| Perranporth Fasteners Ltd | Professional & scientific | 2014 |
| Personnel Recruitment Cornwall Limited | Administrative & support | 2025 |
| Pet Market Retail Limited | Wholesale & retail | 2022 |
| Peter Jones & Sons Limited | Construction | 2023 |
| Petish Limited | Wholesale & retail | 2016 |
| Petrolab Group Limited | Professional & scientific | 2024 |
| Petrolab Limited | Professional & scientific | 2003 |
| PEZ the Barber Ltd | Other services | 2021 |
| Phaby and Luke Ltd | Construction | 2018 |
| Phantom Screen Print Limited | Wholesale & retail | 2011 |
| Pharmalink Southwest Ltd | Education | 2023 |