| Olluri Holding AS | | 2020 |
| Olsen & Wallum AS | Construction | 2023 |
| Omb Bygge Service AS | Real estate | 2026 |
| Omlidtunet AS | Wholesale & retail | 2021 |
| Onkel Skrue Eiendom AS | Real estate | 2006 |
| Onkelb AS | Information & communication | 2025 |
| Onsik Holding AS | | 2021 |
| Ontel AS | Wholesale & retail | 2015 |
| Optima Prima AS | Professional & scientific | 2013 |
| Ornell Leyser AS | Wholesale & retail | 2019 |
| Oslo Performance Training | Education | 2013 |
| Otium Konsept AS | Professional & scientific | 2024 |
| Otterdal Consulting AS | Professional & scientific | 2018 |
| Our Interior AS | Wholesale & retail | 2019 |
| Ove Dahl Holding AS | Construction | 2009 |
| Overflatetjenester AS | Manufacturing | 2018 |
| Oz Media AS | Arts & recreation | 2018 |
| P Saga Holding AS | | 2022 |
| P. Arntzen Holding AS | | 2020 |
| P. Paulsen Holding AS | | 2005 |
| Pabak AS | Professional & scientific | 2006 |
| Padel House AS | Arts & recreation | 2020 |
| Padel Larvik AS | Arts & recreation | 2021 |
| Paks AS | Real estate | 2006 |
| Paltaci AS | | 2024 |
| Parc Fermé AS | Information & communication | 2019 |
| Parkeringshuset P7 Larvik AS | Real estate | 2019 |
| Partners Invest AS | Real estate | 1995 |
| Pascal Automasjon Larvik AS | Construction | 2022 |
| Pascal Tavle AS | Manufacturing | 2023 |
| Patek Eiendom AS | Real estate | 2004 |
| Patina Møbler | Wholesale & retail | 2004 |
| Patrick Kristoffersen | Construction | 2013 |
| Paul a Tutvedt AS | Professional & scientific | 2022 |
| Paulsen Haukås AS | | 2017 |
| PC Trafikkskole AS | Education | 2005 |
| PCS Pulverlakk AS | Manufacturing | 1988 |
| Pedal People AS | Arts & recreation | 2013 |
| Peder Haakestad AS | Administrative & support | 1988 |
| Pefa Rådgiving & Interimledelse AS | Professional & scientific | 2021 |
| Peholding AS | | 2022 |
| Pen Beauty Salong & Thaimassasje AS | Other services | 2017 |
| Pepe Holding AS | | 2004 |
| Pepperoni AS | | 2024 |
| Pepperoni.Com AS | | 2024 |
| Pepvik AS | Hospitality | 2022 |
| Per Christiansen Eiendom & Utleie AS | Real estate | 2001 |
| Per Olav Helgeland AS | Information & communication | 2012 |
| Perico Eiendom AS | Real estate | 2002 |
| Peskovic Holding AS | Professional & scientific | 2021 |
| Petter Kristensen Holding AS | Administrative & support | 2005 |
| Petter Wiik AS | Arts & recreation | 2005 |
| Pettersen Mur & Flis AS | Construction | 2022 |
| Pevh Invest AS | Financial services | 2005 |
| PH Madison AS | Professional & scientific | 2022 |
| Pianolarsen AS | Other services | 2018 |
| Pick Up Service AS | Wholesale & retail | 2006 |
| Pinuslacala AS | Real estate | 2019 |
| Plantadd AS | Wholesale & retail | 2024 |
| Planteland Ringdal AS | Agriculture & fishing | 2026 |
| Plausibel Invest AS | Financial services | 2020 |
| Play AS | Information & communication | 2023 |
| Plero AS | Information & communication | 2024 |
| Plero Holding AS | | 2025 |
| Plisseshop AS | Wholesale & retail | 2021 |
| Plug Larvik AS | Transport & logistics | 2024 |
| Plusoffice AS | Information & communication | 2017 |
| Pluss Forvaltning AS | Real estate | 2013 |
| Pmax Capital AS | | 2025 |
| Pops Invest AS | Wholesale & retail | 2020 |
| Port-Service Holding AS | Construction | 2012 |
| Port-Service Øst AS | Construction | 2012 |
| Portservice Eiendom Ans | Real estate | 1993 |
| Post-Gården AS | Real estate | 2008 |
| Powerstat AS | Information & communication | 2016 |
| PP Senteret AS | Real estate | 2016 |
| PPC Trading Da | Wholesale & retail | 2004 |
| Pre Empt AS | Information & communication | 2022 |
| Precision Sveis AS | Manufacturing | 2026 |
| Preseptor AS | Professional & scientific | 2016 |
| Prestasjonsutvikling AS | Education | 2020 |
| Pretak AS | Manufacturing | 2021 |
| Priimal Technologies AS | Information & communication | 2020 |
| Primo Norge AS | Wholesale & retail | 1995 |
| Prinsegata 8 Larvik AS | Real estate | 2025 |
| Prinsegata Eiendom AS | Real estate | 2021 |
| Prinsekvartalet AS | Real estate | 2021 |
| Private Networks AS | Information & communication | 2025 |
| Pro Search AS | Administrative & support | 2008 |
| Process Partner AS | Wholesale & retail | 1997 |
| Proff Norge AS | Wholesale & retail | 1992 |
| PROFF1 Montasjemateriell Larvik AS | Wholesale & retail | 2020 |
| Proffe Boligpartner AS | Construction | 2019 |
| Proffe Holding AS | Construction | 2022 |
| Proffvindu AS | Professional & scientific | 2014 |
| Profilkompaniet AS | Manufacturing | 2011 |
| Propartner Tak AS | Construction | 2026 |
| Prosjekt Bergstien 6 AS | Real estate | 2021 |
| Prospect AS | Real estate | 1987 |
| Prsvindland AS | Professional & scientific | 2013 |