| Nora X Duttes AS | Wholesale & retail | 2018 |
| Nora, Nasjonal Og Regional Arena for Dans I Telemark AS | Education | 2011 |
| Norbo Eiendom Da | Real estate | 1999 |
| Norborg Maskin & Utleie Service AS | Construction | 2025 |
| Norbras AS | Construction | 1997 |
| Nord Marin AS | Wholesale & retail | 2006 |
| Nord Star Båt AS | Wholesale & retail | 2022 |
| Nordbake AS | Manufacturing | 2007 |
| Nordbohus Skien AS | Construction | 2024 |
| Nordfrim Norge AS | Wholesale & retail | 2021 |
| Nordgård Bil AS | Wholesale & retail | 2015 |
| Nordholding AS | Construction | 2019 |
| Nordic Plastic Surgery Institute AS | Health & social care | 2026 |
| Nordic Support AS | Professional & scientific | 2022 |
| Nordicg AS | Information & communication | 2026 |
| Nording AS | Financial services | 2015 |
| Nordinvest AS | Construction | 2019 |
| Nordkvelle Invest AS | Real estate | 2016 |
| Nordlo Grenland AS | Information & communication | 2009 |
| Nordraaks AS | Real estate | 2007 |
| Nordre Venstøp AS | Real estate | 2005 |
| Nordrox Mining AS | Professional & scientific | 2026 |
| Nordsia AS | Real estate | 2018 |
| Nordskog Multibygg AS | Construction | 2007 |
| Nordskog Og Rød Multiservice AS | Construction | 2024 |
| Nordskog Utvikling AS | Real estate | 2022 |
| Nordstil AS | Wholesale & retail | 2025 |
| Norges Bil AS | Wholesale & retail | 2020 |
| Norgrips AS | Wholesale & retail | 2025 |
| Norlift Special Vehicles AS | Other services | 2016 |
| Norrman Sprinklerkontroll AS | Professional & scientific | 2020 |
| Norrøna Grenland AS | Real estate | 2013 |
| Norsjø Holding AS | Real estate | 2014 |
| Norsjøhus AS | Real estate | 2026 |
| Norsk Bygg Entreprenør AS | Real estate | 2025 |
| Norsk Dyrehelse AS | Wholesale & retail | 2019 |
| Norsk Erosjon Og Flomsikring AS | Professional & scientific | 2017 |
| Norsk Everit AS | Manufacturing | 1986 |
| Norsk Førstehjelps Undervisning AS | Education | 2022 |
| Norsk Hundesenter AS | Education | 2022 |
| Norsk Kjededrift AS | Administrative & support | 1998 |
| Norsk Kjøretøy Kontroll AS | Professional & scientific | 2001 |
| Norsk Kombucha AS | Wholesale & retail | 2014 |
| Norsk Piperehabilitering AS | Construction | 2016 |
| Norsk Redning Og Førstehjelp Ans | | 1986 |
| Norsk Skogsvern AS | Agriculture & fishing | 2023 |
| Norske Regskilt AS | Manufacturing | 2008 |
| Norsnekk Snekkerservice AS | Construction | 2018 |
| Nortello AS | Administrative & support | 2025 |
| NORTH2POWER AS | Information & communication | 2021 |
| Northern Angels AS | | 2022 |
| Norvino AS | Wholesale & retail | 2022 |
| Norway Invest AS | Financial services | 2017 |
| Norway Management AS | Information & communication | 2019 |
| Norway Security AS | Professional & scientific | 2018 |
| Norway Steel Group AS | Wholesale & retail | 2018 |
| Norway Steel Invest AS | Wholesale & retail | 2016 |
| Norway Steel Solutions AS | Wholesale & retail | 2004 |
| Norwegian Dynamics AS | Professional & scientific | 2024 |
| Norwegian Fastener House AS | Wholesale & retail | 2021 |
| Norwegian Made AS | Professional & scientific | 2016 |
| Norwegian Payment Solutions AS | Professional & scientific | 2014 |
| Nossek Invest AS | Construction | 2013 |
| Nova Mentis AS | Information & communication | 2025 |
| Nova Nexus AS | Professional & scientific | 2025 |
| November Holding AS | Real estate | 2020 |
| Novita Omsorg AS | Health & social care | 2023 |
| Novo Surfaces AS | Professional & scientific | 2025 |
| NR 1 Trafikkskole Skien, Da | Education | 2010 |
| NS Motorgroup AS | Wholesale & retail | 2024 |
| NSG Estate AS | Real estate | 2013 |
| NTK Byggtjenester AS | Construction | 2022 |
| Nu Studio Da | Professional & scientific | 2003 |
| Numis AS | Wholesale & retail | 2016 |
| Numme Eiendom AS | Real estate | 2017 |
| Ny Skog AS | Agriculture & fishing | 2022 |
| Nybergflata 2 AS | Real estate | 2021 |
| Nye Farger Grenland AS | Construction | 2026 |
| Nye Sentrum Hårstudio Da | Other services | 1993 |
| Nylende Byggsenter AS | Real estate | 1997 |
| Nypotatis AS | Professional & scientific | 2025 |
| Nær App AS | Information & communication | 2026 |
| Nærum Eiendom AS | Real estate | 2019 |
| Næss Frisør AS | Other services | 2013 |
| O P Sondresen AS | Wholesale & retail | 1976 |
| O Sveinsson Gravemaskindrift AS | Construction | 1975 |
| O.B. Holding AS | Real estate | 2016 |
| O.B. Maskin AS | Construction | 2017 |
| Oasen Skole Grenland AS | Education | 2021 |
| Oask Legetjenester Limited Nuf | Health & social care | 2025 |
| Oda Eiendom AS | Other services | 2000 |
| Oddis Fix AS | Other services | 2025 |
| Odds Ballklubb Eiendom AS | Real estate | 2006 |
| Offshoreveien AS | Professional & scientific | 2020 |
| Ogsåvidere Transport AS | Transport & logistics | 2019 |
| Ojo AS | Financial services | 2013 |
| Okk Elektro Holding AS | Construction | 2015 |
| Oksøya Vann-Og Avløpsselskap AS | Water & waste | 2007 |
| Oktarin AS | | 2018 |
| Olaf Sterner AS | Construction | 1983 |