| Arbeidsjernet AS | Administrative & support | 2015 |
| Arbion Industries Group AS | | 2025 |
| Arca Glass Og Fasade AS | Construction | 2018 |
| Arcade Drilling AS | Mining & quarrying | 1990 |
| Arcano AS | Professional & scientific | 2020 |
| Archer Elemental Norway AS | Professional & scientific | 2024 |
| Archer Wind AS | Professional & scientific | 2020 |
| Archontakis Holding AS | | 2026 |
| Arctander Invest & Consulting AS | Real estate | 2011 |
| Arctech Energy AS | Professional & scientific | 2021 |
| Arctech Holding AS | Professional & scientific | 2024 |
| Arctic Holding AS | Hospitality | 2021 |
| Arctic King Prawns AS | Agriculture & fishing | 2017 |
| Arctic Solutions Invest AS | | 2013 |
| Arctic Spiseri AS | Hospitality | 2017 |
| Arcticode AS | Administrative & support | 2018 |
| Arctix AS | Administrative & support | 2024 |
| Arda Energy AS | Professional & scientific | 2016 |
| Ardan AS | Professional & scientific | 2022 |
| Ardor & Company AS | Other services | 2021 |
| Area Nygård Invest AS | | 2016 |
| Arealstrategi AS | Real estate | 2025 |
| Arena Treningssenter AS | Arts & recreation | 1997 |
| Arendal Spirit AS | Mining & quarrying | 2017 |
| Arendal Spirit L.L.C. Nuf | Mining & quarrying | 2019 |
| Arete Investering AS | | 2014 |
| Arete Partners AS | Professional & scientific | 2021 |
| Argon AS | | 2026 |
| Argon Norway AS | Manufacturing | 2025 |
| Argon Solutions AS | Information & communication | 2026 |
| Arhela AS | | 2023 |
| Aria Asset Management AS | Professional & scientific | 2017 |
| Ariasprocess AS | Professional & scientific | 2023 |
| Arietes Invest AS | | 2020 |
| Ark. Knud Øgreid AS | Real estate | 2018 |
| Arkaden Tannhelse AS | Health & social care | 2021 |
| Arkinaut AS | Professional & scientific | 2020 |
| Arkipartner AS | Professional & scientific | 1982 |
| Arkipel AS | | 2020 |
| Arkitekt Erik Bjørnstad AS | Professional & scientific | 2012 |
| Arkitekt Kaada AS | Professional & scientific | 2012 |
| Arkitekt Katrine Grimnes AS | Professional & scientific | 2025 |
| Arkitekt Smedvig AS | Professional & scientific | 2014 |
| Arkitektfirma Helen & Hard AS | Professional & scientific | 1997 |
| Arkitektfirma Hoem & Folstad AS | Professional & scientific | 1993 |
| Arkitektkontoret Arne Hoffmann Mnal Nuf | Professional & scientific | 2008 |
| Arkitektkontoret Schjelderup & Gram AS | Professional & scientific | 1995 |
| Arkitekton AS | Professional & scientific | 2021 |
| Arleal AS | | 2024 |
| Arn Invest AS | Real estate | 2019 |
| Arne Garborgs Veg 16 AS | Real estate | 2025 |
| Arne Garborgsvei 15 Og 17 AS | Real estate | 2023 |
| Arne Hidle & Co AS | Real estate | 1935 |
| Arne Lærdal AS | Real estate | 2010 |
| Arne Sivertsen Invest AS | Real estate | 2005 |
| Arneageren Eiendom AS | Real estate | 2003 |
| Arnfinn Invest AS | Professional & scientific | 2005 |
| Arnøy Revisjon Og Rådgivning AS | Professional & scientific | 2022 |
| Arominne AS | Wholesale & retail | 2025 |
| Aronia Nordic AS | Wholesale & retail | 2025 |
| Arriva Chartering AS | Transport & logistics | 2015 |
| Arriva Holding AS | Transport & logistics | 2005 |
| Arriva Holding Eiendom AS | Real estate | 2024 |
| Art Republic AS | Wholesale & retail | 2017 |
| Arta Holding AS | Professional & scientific | 2014 |
| Arta Kyb AS | Information & communication | 2026 |
| Artapluss 1 AS | Professional & scientific | 2021 |
| Artapluss AS | Professional & scientific | 2017 |
| Artbolig AS | Real estate | 2006 |
| Artemes AS | Administrative & support | 2021 |
| Artemes Group AS | Administrative & support | 2015 |
| Artemes Invest AS | Real estate | 2017 |
| Artemis Search & Selection AS | Administrative & support | 2019 |
| Artemisia AS | Professional & scientific | 2024 |
| Artha BS AS | Professional & scientific | 2025 |
| Arthoma AS | Professional & scientific | 2026 |
| Arthur Og Frank Lydstudio Da | Information & communication | 2019 |
| Artis AS | Professional & scientific | 2005 |
| Artistfellesskapet AS | Arts & recreation | 2023 |
| Aruba Holding AS | | 2025 |
| Arul Holding AS | | 2025 |
| Aruru AS | | 2020 |
| Arve's Mat AS | Education | 2015 |
| Arwen Holding AS | | 2022 |
| Arx Capital AS | Real estate | 2026 |
| AS Bilgaarden | Real estate | 1934 |
| AS Bilomsetningen | Real estate | 1955 |
| AS Broremann | Hospitality | 2026 |
| AS Engroshuset | Real estate | 1969 |
| AS Fjelde | Real estate | 2016 |
| AS Gardintrylleriet | Manufacturing | 2019 |
| AS Grønnevik Eiendom | Real estate | 1983 |
| AS Grønnevik Maskin | Administrative & support | 1989 |
| AS Hillevågsveien 100 | Real estate | 1987 |
| AS Home Again | Real estate | 2015 |
| AS Irishman | Hospitality | 2014 |
| AS Jærinformasjon | Real estate | 1982 |
| AS Leo Aanonsen | Wholesale & retail | 1975 |
| AS Lkfjelde | Hospitality | 2018 |
| AS Lkfjelde I | Hospitality | 2018 |