| Oaten Technologies Limited | Information & communication | 2022 |
| Ocean & Oasis Limited | Professional & scientific | 2026 |
| Officework Software Limited | Administrative & support | 2016 |
| Offk Ltd | Professional & scientific | 2018 |
| Old Blundells Garage Limited | Professional & scientific | 1938 |
| Old Mill Close Open Space Management Company Limited | Real estate | 2009 |
| Old School Court Amenity Ltd | Real estate | 2021 |
| Old Shute Estates Limited | Financial services | 2012 |
| Olive & Gray Consulting Ltd | Information & communication | 2016 |
| Olmais Interiors Ltd. | Construction | 2004 |
| One MID Devon CIC | Financial services | 2021 |
| Onyx Mountain Sports Ltd | Arts & recreation | 2018 |
| Ooms Moore Limited | Construction | 2003 |
| Opal Entanglement Ltd | Education | 2022 |
| Open Intelligence Ltd | Information & communication | 2019 |
| Open Storehouses | Other services | 2009 |
| OPT Legal Limited | Financial services | 2018 |
| Optimum Electrical SW Ltd | Construction | 2026 |
| Orchard & Bolt Construction Ltd | Construction | 2018 |
| Orchard Route Limited | Wholesale & retail | 2026 |
| Orchestr.Sh Ltd | Information & communication | 2026 |
| Origin 3 Legal Limited | Professional & scientific | 2019 |
| Original Forgery Limited | Manufacturing | 2001 |
| Ormidale Limited | Real estate | 1989 |
| Osteo and Physio Crediton Ltd | Health & social care | 2024 |
| Osteo and Physio Exmouth Ltd | Health & social care | 2023 |
| Osteo and Physio Tiverton Ltd | Other services | 2020 |
| OTF Construction Ltd | Construction | 2023 |
| OTL Brew Co Ltd | Manufacturing | 2018 |
| Outsee Analytics Ltd | Professional & scientific | 2025 |
| Overtureone Limited | Administrative & support | 2019 |
| P & S Auto Solutions Ltd | Wholesale & retail | 2024 |
| P & S Hose & Hydraulics Ltd | Wholesale & retail | 2025 |
| P D Moore Ltd | Construction | 2002 |
| P Wilde Electrical Contractor Limited | Manufacturing | 2016 |
| PA Resources Overseas | Mining & quarrying | 1997 |
| Packaging Suppliers Global Limited | Administrative & support | 2023 |
| Papel Building Solutions Limited | Construction | 2021 |
| Parc Garland Ltd | Construction | 2017 |
| Parc Garland Management Company Limited | Households | 2019 |
| Park Hill Nursery Limited | Education | 2014 |
| Park Hill Veterinary Clinic Limited | Professional & scientific | 2014 |
| Park's Machinery Ltd | Wholesale & retail | 2024 |
| Parker Roofing SW Ltd | Construction | 2019 |
| Parker Scaffold Ltd | Construction | 2013 |
| Parkfield Dental Surgery Limited | Health & social care | 2006 |
| Parkside Garage (Exeter) Limited | Wholesale & retail | 2014 |
| Partridge Farms Limited | Agriculture & fishing | 2003 |
| Paul Cook Master Thatchers Ltd | Construction | 2019 |
| Paul Steele Limited | Professional & scientific | 1995 |
| Paul Vigurs Ltd | Construction | 2009 |
| Pavitt Consulting Ltd | Information & communication | 2006 |
| Paws for Pleasure Limited | Arts & recreation | 2022 |
| PC Autocare Limited | Wholesale & retail | 2010 |
| Peachey Collectibles Limited | Wholesale & retail | 2020 |
| Peakstone Building Ltd | Construction | 2010 |
| Peamore Park Farm Limited | Agriculture & fishing | 2010 |
| Peloton Land Ltd | Real estate | 2021 |
| Penhill Farm Limited | Agriculture & fishing | 1997 |
| Penny Wood Talks Ltd | Professional & scientific | 2016 |
| Perpetual Padel Ltd | Wholesale & retail | 2026 |
| Perreyman Court Management Company Limited | Real estate | 2014 |
| Persey Portfolio Limited | Real estate | 2025 |
| Personal Buyer Service Limited | Wholesale & retail | 2012 |
| PH Auto Parts Ltd | Wholesale & retail | 2023 |
| Phoenix Adult Services Limited | Real estate | 2015 |
| Phoenix Central Services Limited | Administrative & support | 2025 |
| Phoenix Children's Homes Limited | Health & social care | 2005 |
| Phoenix Learning & Care Group Limited | Professional & scientific | 2012 |
| Phoenix Renovations Limited | Construction | 2024 |
| Phoenix Schools (North) Limited | Education | 2026 |
| Phoenix Schools (South) Limited | Education | 2025 |
| Physical Edge (South West) Limited | Arts & recreation | 2019 |
| Pigments Tattoo & Piercing Limited | Administrative & support | 2014 |
| Pilliven Farming Limited | Extraterritorial | 2009 |
| Pioneer 4X4 Limited | Manufacturing | 2016 |
| Pipra UK Ltd | Information & communication | 2021 |
| PJS Tax Consultants Limited | Professional & scientific | 2015 |
| Planet & People CIC | Education | 2021 |
| Platinum Gate Security Ltd | Administrative & support | 2012 |
| Play House SW Ltd | Arts & recreation | 2014 |
| Plumbsmiths Limited | Construction | 2022 |
| Plymtree Careers Limited | Administrative & support | 2011 |
| Polar Coordinate Wine Ltd | Manufacturing | 2023 |
| Polglaze Limited | Construction | 2018 |
| Polka DOT Elephant Ltd | Professional & scientific | 2016 |
| Polkadot Jewellery Limited | Wholesale & retail | 2015 |
| Popple Advisory Ltd | Professional & scientific | 2021 |
| Poultry Litter Treatment Limited | Extraterritorial | 2010 |
| Power Farmers and Gardeners Limited | Real estate | 1948 |
| Power Tool Systems Limited | Manufacturing | 2014 |
| Poynberg Limited | Real estate | 2018 |
| Precision Construction Services (SW) Ltd | Administrative & support | 2020 |
| Predator Exhausts Limited | Manufacturing | 2019 |
| Predator Profiles Limited | Manufacturing | 2013 |
| Predator Styling Limited | Manufacturing | 2006 |
| Press Properties Limited | Construction | 2003 |
| Pro-Act Marketing Ltd | Professional & scientific | 2009 |
| Pro-Protect Limited | Financial services | 2011 |
| Processify IO Ltd | Wholesale & retail | 2023 |