| Arild Eide AS | Wholesale & retail | 2000 |
| Ario Hse & Ce Solutions Nuf | Professional & scientific | 2026 |
| Aristoteles Eiendom AS | Real estate | 2008 |
| Ariya AS | Other services | 2026 |
| Arjems Ans | Administrative & support | 1999 |
| Arjo Hygiene AS | Wholesale & retail | 2014 |
| Ark. Christies Gate 4B AS | Real estate | 2007 |
| Ark. Christies Gate 9 AS | Real estate | 2007 |
| Arkitekt Sandmark AS | Professional & scientific | 2019 |
| Arkitektene Vis-A-Vis AS | Professional & scientific | 1996 |
| Arkitektkollegiet AS | Professional & scientific | 2018 |
| Arkitektkontoret Odd Thommesen AS | Professional & scientific | 2008 |
| Arkitekturfabrikken AS | Professional & scientific | 2012 |
| Arkiv- Og Samlingstjenester AS | Administrative & support | 2021 |
| Arktis AS | | 2025 |
| Arktis Creative AS | Professional & scientific | 2025 |
| Arlø AS | Financial services | 2005 |
| Arm Norway AS | Information & communication | 2001 |
| Arman V AS | Education | 2013 |
| Armani Holding AS | Wholesale & retail | 2021 |
| Armfelt Eiendom AS | Real estate | 2007 |
| Arne Jakobsen AS | Professional & scientific | 2006 |
| Arne Rønning Invest AS | | 2005 |
| Arnec AS | Real estate | 2016 |
| Arnec Bolig AS | Real estate | 2023 |
| Arnec Utvikling AS | Real estate | 2021 |
| Arnes Holdings AS | | 2021 |
| Arnesen Holding AS | Real estate | 2005 |
| Arnin AS | Financial services | 2012 |
| Arnnords AS | | 2022 |
| Arnstein J. Syltern Invest AS | Financial services | 2011 |
| Arntsen Transport AS | Transport & logistics | 2017 |
| Arntzen Propiedad AS | Real estate | 2012 |
| Arntzen Software AS | Information & communication | 2018 |
| Arnøys Foto Ans | Professional & scientific | 1990 |
| Aro AS | Real estate | 1991 |
| Aro Eiendom AS | Real estate | 2015 |
| Aroco - a Robotics Company AS | Professional & scientific | 2026 |
| Arol Holding AS | Real estate | 2018 |
| Aron Jats AS | Hospitality | 2024 |
| Aron Lyni AS | Hospitality | 2017 |
| Aron Trappehuset AS | Hospitality | 2015 |
| Around Systems AS | Professional & scientific | 2022 |
| Arrowhead Invest AS | | 2023 |
| Art Holding AS | Construction | 2024 |
| Artful Crafting AS | Health & social care | 2021 |
| Artscene Trondheim AS | Information & communication | 2013 |
| Arttik Da | Arts & recreation | 2019 |
| Arv Eiendom Holding AS | | 2023 |
| Arve B-S Holding AS | | 2024 |
| Arve Nilssen AS | Administrative & support | 2017 |
| Arvefordeling AS | Information & communication | 2026 |
| Arven Vintage AS | Wholesale & retail | 2020 |
| Arveprinsen AS | | 2020 |
| Arw Brannsikring AS | Construction | 2022 |
| Arw Eiendom AS | Real estate | 2025 |
| Arw Entreprenør AS | Construction | 2013 |
| Arw Entreprenør Ålesund AS | Construction | 2025 |
| Arw Holding AS | Construction | 2021 |
| Arw Takkontroll AS | Professional & scientific | 2019 |
| Arzevo AS | Information & communication | 2025 |
| AS a J Nilsson | Real estate | 1918 |
| AS AI & Eye | Health & social care | 2020 |
| AS Anderssen Bygg Invest | Real estate | 1985 |
| AS Ara | Real estate | 1988 |
| AS Autocentralen Av 1925 | Real estate | 2018 |
| AS Abels gt. nr. 2 | Households | 1923 |
| AS Bakkestua | Households | 1946 |
| AS Blikkenslager Olaf Hansen | Construction | 1987 |
| AS Brødrene Hellen | Real estate | 1912 |
| AS Byggservice | Construction | 2003 |
| AS Bøndernes Hus | Real estate | 1916 |
| AS Elgeseterg 26 | Households | 1957 |
| AS Elgeseterg 40 | Households | 1958 |
| AS Fallem Olsø | Health & social care | 2023 |
| AS Fast Eiendom | Real estate | 1972 |
| AS Fjæregata 2 | Households | 1959 |
| AS Forbunds Og Foreningsservice | Real estate | 1974 |
| AS Fosenferja | Arts & recreation | 2020 |
| AS Freyjata | | 2021 |
| AS Fjellseterveien 32 | Households | 1957 |
| AS Griffenfeldts GT 1 | Households | 1956 |
| AS Heimdal Naturstein | Manufacturing | 1987 |
| AS J Petersens Beslagfabrik | Manufacturing | 1999 |
| AS Jafreyja | | 2021 |
| AS Johan Svendsens Gate 4 | Households | 1946 |
| AS John & Kaare Christiansen | Real estate | 1991 |
| AS Klæbuveien 157 | Households | 1950 |
| AS Klæbuveien 55 | Households | 1923 |
| AS Lykkegården | Real estate | 1966 |
| AS Mercur | Real estate | 1945 |
| AS Nedre Møllenberg GT 49 | Households | 1956 |
| AS Nedre Møllenberg GT 83 | Households | 1956 |
| AS Olav Engelbrektssons Alle 41-47 | Households | 1956 |
| AS Olav Tryggvassonsg 17 | Real estate | 1900 |
| AS Regnskap & Kontor | Professional & scientific | 1989 |
| AS Rekkehus | Households | 1989 |
| AS Revisjonssentralen | Financial services | 1970 |
| AS Schøyens GT 8 | Households | 1924 |
| AS Skjæringen | Households | 1956 |