| Overby Innovation AS | | 2016 |
| Overrein Ikt Og Consulting AS | Wholesale & retail | 2013 |
| Overvik Bygginvest 1 AS | | 2018 |
| Overvik Lokalsenter AS | Real estate | 2016 |
| Overvik Maskin AS | Construction | 2014 |
| Overvik Panorama 1 AS | Real estate | 2018 |
| Overvik T1 AS | Real estate | 2015 |
| Overvik Utvikling AS | Real estate | 2013 |
| Ovesen Servicepartner AS | Other services | 2021 |
| Owb Invest AS | | 2026 |
| Oxaal Holding AS | Real estate | 2014 |
| Oxide AS | Information & communication | 2025 |
| Oxvold Invest AS | Manufacturing | 2008 |
| Oxyflow Testlab AS | Health & social care | 2021 |
| Oxygen Design AS | Professional & scientific | 2000 |
| Oyster Invest AS | | 2026 |
| Oywan 082 Holding AS | | 2023 |
| P & P Invest AS | | 2008 |
| P Baadsvik Holding AS | | 2025 |
| P Blakstad AS | Wholesale & retail | 1986 |
| P E Bomo AS | Financial services | 2017 |
| P&A Holding AS | Real estate | 2011 |
| P&A Property AS | Real estate | 2012 |
| P&J Holding AS | Real estate | 2021 |
| P-Holding AS | Hospitality | 2004 |
| P-Hotels Brattøra AS | Hospitality | 2012 |
| P-West Eiendom AS | | 2023 |
| P. Eian Holding AS | Real estate | 2020 |
| P. Engelsen Holding AS | | 2017 |
| P.A. Hoff Holding AS | | 2005 |
| P.H.D Eat AS | Hospitality | 2024 |
| P.T.P Holding AS | | 2024 |
| P2EM AS | Professional & scientific | 2018 |
| Pa Hamre Holding AS | Financial services | 2016 |
| Pa NEWCO53 AS | | 2026 |
| Pa NEWCO55 AS | | 2026 |
| Pa NEWCO56 AS | | 2026 |
| Paal Aagaard Svømmekonsult AS | Education | 2014 |
| Paco Music AS | Professional & scientific | 2012 |
| Pacta Eiendom AS | Real estate | 2001 |
| Padletur AS | Education | 2018 |
| Paintbox Pro AS | Wholesale & retail | 2008 |
| Pakpoom Holding AS | | 2025 |
| Pal Agenturer Ans | | 1991 |
| Paleoterapeuten AS | Health & social care | 2014 |
| Palermo Restaurant & Pizzeria AS | Hospitality | 2004 |
| Palion Medical AS | Wholesale & retail | 2019 |
| Palle Jørgensen Holding AS | | 2017 |
| Palsson AS | Wholesale & retail | 2014 |
| Pan AS | | 2020 |
| Pan Musikk Ans | Wholesale & retail | 1985 |
| Pancho Burrito Bar AS | Hospitality | 2017 |
| Panda 4 Fun AS | | 2018 |
| Panda Investing AS | | 2013 |
| Pandaspons AS | Other services | 2022 |
| Panghea Nordic AS | Wholesale & retail | 2020 |
| Panino AS | | 2020 |
| Papagayo Energy AS | Energy | 2009 |
| Papilio AS | Wholesale & retail | 2015 |
| Papir Og Design AS | Wholesale & retail | 2012 |
| Papirverdier AS | | 2025 |
| Para Consult AS | Wholesale & retail | 2000 |
| Parafin Forlag Da | Information & communication | 2006 |
| Parallax AS | Professional & scientific | 2025 |
| Paratum AS | Professional & scientific | 2018 |
| Parfymeri Østhus AS | Wholesale & retail | 1996 |
| Pariserhjulet AS | Hospitality | 2017 |
| Park & Anleggstjenester AS | Administrative & support | 1998 |
| Park by D Haircut AS | Other services | 2025 |
| Parkbygget AS | Real estate | 1999 |
| Parkettstudio Brechan AS | Wholesale & retail | 2005 |
| Parkgata 37 AS | Real estate | 2024 |
| Parkgården Trondheim AS | Arts & recreation | 1917 |
| Parkkafeen Trondheim AS | Hospitality | 2019 |
| Particular Recordings Collective SA | Information & communication | 2016 |
| Partners Investment Da | Professional & scientific | 2019 |
| Party Store AS | Wholesale & retail | 2022 |
| Parvi AS | Professional & scientific | 2026 |
| Pasa Enger AS | Real estate | 2007 |
| Pasdeloup Holding AS | | 2026 |
| Pastalab AS | Hospitality | 2024 |
| Patay Invest AS | Professional & scientific | 2002 |
| Paul Blaikie Golf Academy AS | Education | 2019 |
| Paveto Essens AS | Professional & scientific | 2003 |
| Paymard AS | Professional & scientific | 2017 |
| Payoff Produksjoner AS | Information & communication | 2025 |
| Pbeiendom AS | Construction | 2018 |
| Pbholding AS | Construction | 2017 |
| PBM Eiendom AS | Real estate | 2016 |
| PBM Eiendom Ix AS | Real estate | 2019 |
| PBM Eiendom V AS | Real estate | 2015 |
| PBM Eiendom Vi AS | Real estate | 2015 |
| PBM Eiendom Vii AS | Real estate | 2016 |
| PBM Eiendom Viii AS | Real estate | 2017 |
| PBM Eiendom X AS | Real estate | 2020 |
| Pc.Rehabilitering AS | Construction | 2017 |
| PCL AS | | 2016 |
| PCM Service AS | Administrative & support | 2017 |
| PCM Tech AS | Information & communication | 2025 |
| PCM Utleie AS | Administrative & support | 2016 |