| Aidtec AS | Information & communication | 2026 |
| Aim Capital Partners AS | Professional & scientific | 2022 |
| Air & Road Transport AS | Transport & logistics | 1998 |
| Airport Retail Norway AS | Wholesale & retail | 2004 |
| Airspinn Holding AS | Real estate | 2015 |
| Aj Regnskap AS | Professional & scientific | 2014 |
| Aj Utbygging AS | Real estate | 2020 |
| Akb Lighting AS | Wholesale & retail | 1987 |
| Akb Lighting Eiendom AS | Real estate | 2024 |
| Aker-Iversen AS | Professional & scientific | 2023 |
| Akers Bakeri AS | Manufacturing | 2020 |
| Akh Finans AS | | 2023 |
| Akl Eiendom AS | Financial services | 2005 |
| Akm Service AS | Transport & logistics | 2021 |
| Akse Byggteknikk AS | Professional & scientific | 2021 |
| Aksjeselskapet Christiania Eiendomsselskap | Real estate | 2008 |
| Aktito AS | | 2026 |
| Aktiv Elektro AS | Construction | 2023 |
| Aktiv Kropp AS | Health & social care | 2010 |
| Aktiv Læring AS | Education | 1998 |
| Aktiva Økonomi AS | Professional & scientific | 2016 |
| Aktivt R O M AS | Other services | 2015 |
| Akustikk-Konsult AS | Professional & scientific | 2014 |
| Akustikkpartner AS | Arts & recreation | 2014 |
| Al Holding AS | Financial services | 2005 |
| Alan Eiendom AS | Real estate | 2020 |
| Alan's Eiendom AS | Real estate | 2021 |
| Alba Trafikkskole AS | Education | 2017 |
| Albatross Investering AS | | 2025 |
| Albatrossveien AS | Real estate | 2021 |
| Albinvindu AS | Wholesale & retail | 2014 |
| Alegria Kommunikasjon Da | Professional & scientific | 2004 |
| Alf Larsen AS | Construction | 2004 |
| Alfakrøll AS | Other services | 2000 |
| Alfred Bjørvik Eiendomsselskap AS | Wholesale & retail | 1984 |
| Aliom AS | Wholesale & retail | 2017 |
| Allan Studio AS | Information & communication | 2021 |
| Allegro Invest AS | Real estate | 2000 |
| Allegro Kommunikasjon AS | Information & communication | 2001 |
| Allerød Holding AS | Financial services | 2016 |
| Allmennlegen AS | Health & social care | 2011 |
| Allround Solutions AS | Professional & scientific | 2024 |
| Allum AS | | 1986 |
| Allum Eiendom AS | Real estate | 1994 |
| Allum Engineering AS | Professional & scientific | 1994 |
| Allum Industrier AS | Professional & scientific | 2022 |
| Allum Technology AS | Professional & scientific | 2017 |
| Almehagen Holding AS | Administrative & support | 2016 |
| Alnavet AS | Professional & scientific | 2009 |
| Alo-Analyse AS | Professional & scientific | 2021 |
| Alonsohuset AS | Wholesale & retail | 2019 |
| Alpha Scorpii AS | | 2023 |
| Alsi AS | | 2022 |
| Alth Invest AS | Professional & scientific | 2020 |
| Altvco Holding AS | | 2022 |
| Alu Laukar AS | Education | 2019 |
| Always Football Group AS | Administrative & support | 2022 |
| Am Vestfold AS | Professional & scientific | 2025 |
| Amafine Takst AS | Professional & scientific | 2015 |
| Amalie AS | Real estate | 1989 |
| Amana Beverages AS | Hospitality | 2024 |
| Amanda Frisør AS | Other services | 2020 |
| Amb Investments AS | | 2023 |
| Ambition AS | Financial services | 1984 |
| Ambjørnsen & Larsen Da | Wholesale & retail | 1999 |
| Ambrosia Bygg AS | Real estate | 2024 |
| Ambulatorium AS | Health & social care | 2001 |
| Ameto AS | Real estate | 2006 |
| Ami Biogas AS | Professional & scientific | 2023 |
| Ami Biogas Holding AS | | 2025 |
| Ami Consulting AS | Professional & scientific | 2024 |
| Amiblu Norway AS | Wholesale & retail | 1998 |
| Amiblu Technology AS | Professional & scientific | 1977 |
| Amj. Holding AS | | 2023 |
| Amnis Company AS | Wholesale & retail | 2020 |
| Amo Toys AB Nuf | Professional & scientific | 2026 |
| Amo Toys AS | Wholesale & retail | 2013 |
| Amon Gas Holding AS | Transport & logistics | 2022 |
| Amon Maritime AS | Transport & logistics | 2019 |
| Amon Prosjekt 1 AS | Transport & logistics | 2025 |
| Amorca Holding AS | | 2024 |
| Amspec Norway AS | Professional & scientific | 2024 |
| Amundrød Eiendom AS | Real estate | 2025 |
| Analog Hifi Plinth Design AS | Wholesale & retail | 2014 |
| Anarki Home AS | Wholesale & retail | 2025 |
| Andebu Elektro AS | Construction | 2017 |
| Andebu-Eiendom AS | Construction | 2017 |
| Andelslaget Veierland Sør Avløpslag | Real estate | 2005 |
| Andengaard Holding AS | | 2023 |
| Anders Jensen AS | Construction | 1992 |
| Anders Kamfjord Eiendom AS | Real estate | 2019 |
| Anders Skorge AS | Real estate | 2010 |
| Andersen Assets AS | | 2025 |
| Andersen Elektro Kompetanse AS | Professional & scientific | 2007 |
| Andersen Equity Holding AS | | 2024 |
| Andersen Frugaard Holding AS | | 2020 |
| Andersen Trommestad Holding AS | Real estate | 2020 |
| Andreassen-Invest-As AS | Wholesale & retail | 2023 |
| Andremar Holding AS | Financial services | 2016 |
| André Berggren Holding AS | | 2025 |