| Oavik Capital AS | Professional & scientific | 2008 |
| Oavik Invest AS | Professional & scientific | 2019 |
| Oavik Management AS | | 2023 |
| Odessa AS | Health & social care | 2012 |
| Oksenøya Invest AS | Real estate | 2008 |
| Olea Consulting AS | Professional & scientific | 2006 |
| Olivias Verden AS | Wholesale & retail | 2012 |
| Olivias Verden Asker AS | Wholesale & retail | 2025 |
| Olivias Verden Byporten AS | Wholesale & retail | 2025 |
| Olivias Verden CC Vest AS | Wholesale & retail | 2019 |
| Olivias Verden Ski AS | Wholesale & retail | 2023 |
| Olivias Verden Storo AS | Wholesale & retail | 2018 |
| Olivias Verden Strømmen AS | Wholesale & retail | 2013 |
| Omara Consulting AS | Professional & scientific | 2014 |
| Omara Holding AS | Real estate | 2014 |
| Oneness AS | Health & social care | 2018 |
| Op Holding AS | Real estate | 2005 |
| Opencare AS | Information & communication | 2026 |
| Optimist Eiendomsinvest AS | Real estate | 2024 |
| Oriets Invest AS | | 2019 |
| Osc 2 AS | Education | 2022 |
| Oslo Bygg Miljø AS | Construction | 2022 |
| Oslo Eiendoms Partner AS | Real estate | 1988 |
| Oslo Fasadeservice Limited Nuf | Administrative & support | 2008 |
| Papirhuset AS | Real estate | 1927 |
| Patritus Holding AS | Financial services | 2005 |
| Pci Bilformidling AS | Wholesale & retail | 2004 |
| PCS Holding AS | | 2022 |
| Pedersen & Co AS | Arts & recreation | 1981 |
| Pentos AS | | 2024 |
| Peon AS | Financial services | 2017 |
| Percolo AS | Wholesale & retail | 2000 |
| Perfect Garden AS | Administrative & support | 2014 |
| Petter Aure AS | Financial services | 2005 |
| PFG AS | Financial services | 2016 |
| PH Capital AS | Financial services | 2013 |
| Philip Holding AS | Real estate | 2019 |
| Pilos AS | Real estate | 2005 |
| Pilos Omsorgseiendom AS | Real estate | 2021 |
| Praevians AS | Professional & scientific | 2008 |
| Prai AS | Information & communication | 2018 |
| Prauss AS | Wholesale & retail | 2006 |
| Produktdesign AS | Professional & scientific | 1981 |
| Proinvestor AS | Professional & scientific | 2011 |
| Project Engineering Services AS | Professional & scientific | 1996 |
| Project Support AS | Real estate | 2012 |
| Propellie Invest AS | | 2025 |
| PS Investments AS | Real estate | 2006 |
| Psykologklinikk AS | Health & social care | 2024 |
| Pto Holding AS | | 2024 |
| Puten Invest AS | Professional & scientific | 2000 |
| Pål Iversen Holding AS | Wholesale & retail | 2005 |
| Quan AS | Financial services | 2010 |
| Quick Island Invest AS | | 2020 |
| R & H Trade Import Ans | | 1987 |
| R. Marius Barstad AS | Health & social care | 2007 |
| Rabsch Rådgivning AS | Professional & scientific | 2019 |
| Radcon Scandinavia AS | Wholesale & retail | 1993 |
| Railzirk AS | Professional & scientific | 2024 |
| Reakthelse AS | | 2026 |
| Redefine AS | Health & social care | 2013 |
| Redwood Capital AS | | 2019 |
| Reksa AS | Real estate | 2026 |
| Rekstrav AS | Financial services | 2005 |
| Remidex Norge AS | Real estate | 1991 |
| Responsiv Kapital I AS | | 2023 |
| Responsiv Kapital II AS | | 2023 |
| Rett & Slett Eiendom AS | Professional & scientific | 2020 |
| Rett & Slett Entreprenør AS | Real estate | 2025 |
| Rett & Slett Holding AS | | 2025 |
| Ridgehaven Ventures AS | Professional & scientific | 2006 |
| Ridgehaven Ventures II AS | | 2020 |
| Rise Invest AS | Professional & scientific | 2007 |
| Robin Forever Invest AS | Real estate | 2020 |
| Rohirrim AS | | 2019 |
| Roots Invest AS | Real estate | 2007 |
| Ropern Industrier AS | Transport & logistics | 2007 |
| Rruud Holding AS | | 2024 |
| Rttm Holding AS | Administrative & support | 2021 |
| Rugz AS | Information & communication | 2001 |
| RUTILUS1 Bergan AS | Professional & scientific | 2021 |
| Ruud Awakening AS | | 2019 |
| Ruud Smooth AS | Administrative & support | 2021 |
| Råde Utleie AS | Real estate | 2019 |
| S-Nilsen 35 Eiendom AS | Real estate | 2003 |
| S3BYGG V/Pasi Jamså | Construction | 2005 |
| Saele Invest & Consulting AS | Wholesale & retail | 2001 |
| Sag Maritime Capital AS | Transport & logistics | 2024 |
| Saltkorn. AS | Information & communication | 2012 |
| Salvatio Invest AS | Real estate | 2022 |
| Sandy Shores AS | | 2020 |
| Sangenuten Holding AS | Health & social care | 2024 |
| Sann Invest AS | Professional & scientific | 2017 |
| Savima AS | | 2005 |
| Savito AS | | 2026 |
| Scanur AS | Professional & scientific | 2005 |
| Scenorama AS | Administrative & support | 2015 |
| Schwanitz Development AS | Real estate | 2011 |
| Sea-Age Invest Nuf | Professional & scientific | 2009 |
| Senior Partners Eiendomsutvikling AS | Real estate | 1992 |