| Osaka Sushi Tønsberg AS | Hospitality | 2010 |
| Oseberg Bygg AS | Real estate | 2004 |
| Oseberg Eiendomsutvikling AS | Real estate | 2004 |
| Oseberg Gruppen AS | | 2023 |
| Oseberg Miljø AS | Administrative & support | 2014 |
| Oseberg Solutions AS | Information & communication | 2000 |
| Osteopatisk Manuell Medisin Ans | Health & social care | 2002 |
| Oti Ledig 2 AS | Manufacturing | 2023 |
| Otium Holding AS | | 2017 |
| Otrol AS | | 2025 |
| Otterlei Eiendom AS | Real estate | 2015 |
| Otterlei Forvaltning AS | Real estate | 2006 |
| Otterlei Fritid AS | Real estate | 1999 |
| Otterlei Invest AS | | 1999 |
| Otterlei Utvikling AS | Real estate | 1997 |
| Outcomes Analytica AS | Professional & scientific | 2019 |
| Outlet City AS | Wholesale & retail | 2025 |
| Ozvol Invest AS | Financial services | 2005 |
| P. Pedersen Holding AS | | 2020 |
| Page One Consultants AS | Wholesale & retail | 1993 |
| Page One Pro AS | Information & communication | 2025 |
| Pallesentralen Tusk Ans | | 1991 |
| Pandas Wok & Sushi Bar AS | Hospitality | 2011 |
| Pantagruel Forlag AS | Information & communication | 1997 |
| Paparazzi AS | Hospitality | 2009 |
| Patrick Eriksson Holding AS | Real estate | 2021 |
| Patrick Kristiansen Invest AS | | 2023 |
| Paulsen Trafikkskole AS | Education | 2024 |
| Paytime AS | Professional & scientific | 2006 |
| Pcbekkedal Holding AS | | 2025 |
| Pean Kunnskap AS | Education | 2024 |
| Pec Elektro Tønsberg AS | Construction | 1995 |
| Pec Rørlegger AS | Construction | 2018 |
| Pegasus Eiendom AS | Real estate | 2005 |
| Peking AS | Hospitality | 2008 |
| Pemberton AS | Wholesale & retail | 2026 |
| Penny Venture AS | | 2021 |
| Pensjonistgutta AS | Administrative & support | 2015 |
| Pent Gress AS | Administrative & support | 2025 |
| Per Eiendom AS | Real estate | 2005 |
| Perfekt Ur AS | Other services | 2021 |
| Pet Installasjon AS | Construction | 1982 |
| Peter Grønsgt. 2B AS | Real estate | 2007 |
| Petersson Invest AS | | 2021 |
| Petex AS | Professional & scientific | 2005 |
| Petra Holding AS | Financial services | 2018 |
| Petrovic Holding AS | | 2025 |
| Pgtk Holding AS | Real estate | 2014 |
| Philia AS | Financial services | 1964 |
| Pico Ti AS | Health & social care | 2025 |
| Pid Solutions AS | Professional & scientific | 2012 |
| Pien SA | Professional & scientific | 2024 |
| Piiksi Services AS | Professional & scientific | 2017 |
| Piil Holding AS | Wholesale & retail | 2022 |
| Pikontong Aroma Thai AS | Other services | 2025 |
| Pingvest AS | | 2023 |
| Pingvin I Vest AS | | 2025 |
| Pixo AS | Health & social care | 2025 |
| Pizzan (Tønsberg) AS | Hospitality | 2024 |
| Planteform AS | Administrative & support | 2024 |
| Plantscape Norge AS | Wholesale & retail | 2018 |
| Planvest AS | Real estate | 1998 |
| Plass AS | Real estate | 2005 |
| Plass Invest AS | Real estate | 2005 |
| Plingplong AS | Information & communication | 2020 |
| PM Tønsberg AS | Real estate | 2005 |
| PNT Group AS | Hospitality | 2025 |
| Podhuset AS | Professional & scientific | 2026 |
| Pointer Holding AS | | 2015 |
| Polight ASA | Professional & scientific | 2005 |
| Polka AS | Financial services | 2005 |
| Polybos AS | Health & social care | 2010 |
| Poppi AS | Wholesale & retail | 2021 |
| Positiv Kompetanse Holding AS | Real estate | 2018 |
| Positiv Kompetanse Norge AS | Administrative & support | 2018 |
| Positive Læringsopplevelser AS | Information & communication | 2025 |
| Positivt Regnskap AS | Professional & scientific | 2023 |
| Posline AS | Wholesale & retail | 2014 |
| Post Reality AS | Professional & scientific | 2016 |
| PQ Eiendom Invest AS | Real estate | 2019 |
| Praline AS | Manufacturing | 2019 |
| Praxis Eiendom AS | Wholesale & retail | 2013 |
| Precira AS | Professional & scientific | 2017 |
| Premium Home AS | Real estate | 1998 |
| Prepi AS | Professional & scientific | 2022 |
| Preppy AS | Wholesale & retail | 2024 |
| Presterød Invest AS | Real estate | 2016 |
| Presterødåsen Gartneri Ans | Agriculture & fishing | 1989 |
| Presterødåsen Gartneri AS | Agriculture & fishing | 2011 |
| Pridok AS | Information & communication | 2013 |
| Primo Communication AS | Professional & scientific | 2024 |
| Priventa AS | Information & communication | 2005 |
| Product Line AS | Wholesale & retail | 2005 |
| Product Line Holding AS | Wholesale & retail | 1990 |
| PROFF1 Montasjemateriell Tønsberg AS | Wholesale & retail | 2000 |
| PROFF1 Norge AS | Wholesale & retail | 2018 |
| Profil Eiendom AS | Real estate | 2021 |
| Profondo Consulting AS | Administrative & support | 2016 |
| Profoyn AS | Professional & scientific | 2014 |
| Profoyn Eie AS | Professional & scientific | 2007 |