| Nordlund AS | Financial services | 2005 |
| Nordre Follo Mur Og Flis AS | Construction | 2017 |
| Norsk Lydproduksjon AS | Arts & recreation | 1993 |
| Norskbadstue AS | Wholesale & retail | 2018 |
| Norske Boblehaller AS | Wholesale & retail | 2003 |
| Northland Skateparks AS | Construction | 2024 |
| Notehuset AS | Wholesale & retail | 2021 |
| Novi Offshore AS | Professional & scientific | 2013 |
| Nye Follo Byggservice AS | Construction | 2024 |
| Nye Myrvoll Kiosk & Video Da | Wholesale & retail | 2000 |
| Occasima AS | | 2022 |
| Odd Consulting AS | Information & communication | 2024 |
| Odlo Næring AS | Real estate | 2015 |
| Oj Fel AS | | 2019 |
| Oki AS | Professional & scientific | 2013 |
| Ompi Holding AS | Real estate | 2019 |
| Oppegård Brus AS | Wholesale & retail | 2020 |
| Oppegård Elektriske AS | Construction | 2011 |
| Oppegård Indoor Golf AS | Arts & recreation | 2025 |
| Oppegård Næringseiendom AS | Real estate | 2025 |
| Oppegård Nærsenter AS | Real estate | 2025 |
| Oppegård Sushi & Wok AS | Hospitality | 2015 |
| Opposite Lock AS | Financial services | 1982 |
| Opposite Lock AS | Wholesale & retail | 2011 |
| Oslo Dance Seminar Da | Education | 2023 |
| Oslo Essentials AS | Wholesale & retail | 2025 |
| Oslo Retail Group AS | Wholesale & retail | 2024 |
| Oslo Vest Rehabilitering AS | Construction | 1998 |
| Outalight AS | Professional & scientific | 2026 |
| Ovis AS | Real estate | 2006 |
| Owl Invest AS | | 2022 |
| Palmar Capital Holding AS | | 2024 |
| Panda Regnskap AS | Professional & scientific | 2024 |
| Pape Kontroll AS | Professional & scientific | 2023 |
| Paperwork Music AS | Information & communication | 2025 |
| Perfekt Rapportering Holding AS | Financial services | 2016 |
| Performa Consulting AS | Professional & scientific | 2009 |
| Petersen and Nymoen International Ans | | 1994 |
| Philipine Invest AS | | 2021 |
| PN Regnskapsbyrå AS | Professional & scientific | 2020 |
| Polar VVS AS | Construction | 2019 |
| Polarstjerne AS | Wholesale & retail | 2021 |
| Pono AS | Information & communication | 2020 |
| Pragh Holding AS | | 2023 |
| Praktiva AS | Real estate | 1976 |
| Precog AS | Information & communication | 2013 |
| Preplay AS | Information & communication | 2014 |
| PRH Consulting AS | Professional & scientific | 2020 |
| Pro Transport AS | Transport & logistics | 2018 |
| Profit Today AS | Professional & scientific | 2025 |
| Property Mapping AS | Real estate | 2018 |
| Protagon AS | Construction | 2023 |
| PT Proffbygg AS | Construction | 2021 |
| På Invest AS | Real estate | 2017 |
| R & R Global Holding AS | Real estate | 2019 |
| Ra Media AS | Professional & scientific | 2015 |
| Ral Holding AS | | 2020 |
| Rana Taksering AS | Real estate | 2012 |
| Rasdal & Haugen Consulting AS | Professional & scientific | 2013 |
| Ravn & by AS | Manufacturing | 2025 |
| Redato AS | Construction | 2019 |
| Renewable Finance Partners AS | Real estate | 2017 |
| Renow AS | Information & communication | 2024 |
| Reqrut.No AS | Professional & scientific | 2026 |
| Requirements Driven Engineering AS | Professional & scientific | 2003 |
| Ringen Holding AS | | 2021 |
| Robert Rydland Holding AS | Wholesale & retail | 2018 |
| Robin AS | Health & social care | 1999 |
| Robin Rotor Holding AS | | 2025 |
| Robin Rotor Norge AS | Information & communication | 2025 |
| Rogcity Holding AS | | 2023 |
| Romano Eiendom AS | Real estate | 2016 |
| Romano Group AS | Professional & scientific | 2012 |
| Roucas AS | Wholesale & retail | 2005 |
| ROYAL9 AS | Professional & scientific | 2025 |
| RP Invest AS | | 2005 |
| S Nerland Holding AS | | 2025 |
| Sabra AS | | 2025 |
| Sahdia Holding AS | | 2024 |
| Saholen Holding AS | | 2023 |
| Saka Holding AS | | 2025 |
| Sama AS | Real estate | 2026 |
| Samer Gjerde Holding AS | Health & social care | 2025 |
| Sanart AS | Construction | 2019 |
| Sance Oslo AS | Wholesale & retail | 2023 |
| SB Kapital AS | Real estate | 2021 |
| Scandinavian Experience AS | Professional & scientific | 2013 |
| Scandinavian Water Technology AS | Wholesale & retail | 2011 |
| Select AS | Wholesale & retail | 1996 |
| Selma Bil AS | Wholesale & retail | 2014 |
| Sharma Eiendom AS | Real estate | 2016 |
| Sideout Holding AS | | 2025 |
| Sigmanta Ans | Construction | 2009 |
| Simen Sandorf Dagligvare AS | Wholesale & retail | 2024 |
| Simen Sandorf Holding AS | Wholesale & retail | 2021 |
| Sisu Holding Invest AS | | 2023 |
| Sivilingeniør Mørkrid AS | Professional & scientific | 1990 |
| Skanva AS | Wholesale & retail | 2015 |
| Skibrek AS | Professional & scientific | 2026 |
| Skillup IT AS | Information & communication | 2024 |