| Arken Investments AS | Real estate | 2019 |
| Arken Rom AS | Real estate | 2020 |
| Arken Teater Ans | Administrative & support | 1990 |
| Arkentype Music AS | Information & communication | 2023 |
| Arketola AS | Information & communication | 2022 |
| Arki Nuf | Arts & recreation | 2022 |
| Arki-Ban AS | Professional & scientific | 2014 |
| Arkil | Transport & logistics | 2013 |
| Arkimedes Holding AS | Information & communication | 2017 |
| Arkitekt Albjerk AS | Professional & scientific | 2014 |
| Arkitekt Amalie Nævisdal Tønnesen Mnal AS | Professional & scientific | 2021 |
| Arkitekt Aslak Haanshuus AS | Professional & scientific | 2020 |
| Arkitekt Audun Andresen AS | Professional & scientific | 2024 |
| Arkitekt Ebbels Vei 10 AS | Real estate | 2006 |
| Arkitekt Folstad, Knut AS | Professional & scientific | 2018 |
| Arkitekt Geir Grung AS | Professional & scientific | 1971 |
| Arkitekt Henriette Helverschou AS | Professional & scientific | 2025 |
| Arkitekt Inga Egeberg AS | Professional & scientific | 2021 |
| Arkitekt Ingrid Steen-Chabert AS | Professional & scientific | 2025 |
| Arkitekt Jonas Løland AS | Professional & scientific | 2024 |
| Arkitekt Lars Larsen AS | Professional & scientific | 2018 |
| Arkitekt Miriam Landa AS | Professional & scientific | 2025 |
| Arkitekt Nikolai Alfsen AS | Professional & scientific | 2005 |
| Arkitekt Per E. Knutsen AS | Professional & scientific | 2024 |
| Arkitekt Stefan Hurrell AS | Professional & scientific | 2026 |
| Arkitektbedriftene Forsikringsservice AS | Financial services | 2005 |
| Arkitekten AS | Professional & scientific | 2018 |
| Arkitektene AS | Professional & scientific | 1977 |
| Arkitektene Astrup Og Hellern AS | Professional & scientific | 1987 |
| Arkitektene Dahl & Myrhol Ans | Professional & scientific | 1987 |
| Arkitektene Dahl & Myrhol AS | Professional & scientific | 1998 |
| Arkitektene Mnal Fosse Og Aasen AS | Professional & scientific | 1991 |
| Arkitektene Nustad Og Wodstrup Da | Professional & scientific | 2000 |
| Arkitektenes Hus Eiendom AS | Real estate | 2014 |
| Arkitektfirmaet Magnus Bruland AS | Professional & scientific | 2000 |
| Arkitektgruppen Lille Frøen AS | Professional & scientific | 1986 |
| Arkitekthus Entreprenør AS | Construction | 2022 |
| Arkitektkontoret Andberg-Moum Hemsen AS | Professional & scientific | 2016 |
| Arkitektkontoret Anne Grete Solstad AS | Professional & scientific | 1998 |
| Arkitektkontoret Haaland AS | Professional & scientific | 2005 |
| Arkitektkontoret Lene Frank AS | Professional & scientific | 1996 |
| Arkitektkontoret Pinnen AS | Professional & scientific | 2021 |
| Arkitektrommet AS | Professional & scientific | 2019 |
| Arkitektur Norge AS | Professional & scientific | 2021 |
| Arkitektur Og Transformasjon AS | Professional & scientific | 2026 |
| Arkitema AS | Professional & scientific | 1986 |
| Arkiv.No Da | Professional & scientific | 2000 |
| Arkivet Casting AS | Information & communication | 2025 |
| Arkivet Hegdehaugsveien AS | Wholesale & retail | 2020 |
| Arko Gruppen AS | Construction | 2026 |
| Arko Transport AS | Transport & logistics | 2025 |
| Arkon Holding AS | | 2020 |
| Arktaria Group AS | | 2025 |
| Arktaria Oslo AS | Information & communication | 2025 |
| Arktekk AS | Information & communication | 2014 |
| Arktis Mnrl I AS | Information & communication | 2011 |
| Arktis Nordic Holding AS | Financial services | 2007 |
| Arktisk - Fisk AS | Wholesale & retail | 2024 |
| Arktos AS | Professional & scientific | 2007 |
| Arktura AS | Information & communication | 2019 |
| Arkwright Consulting AS | Professional & scientific | 2011 |
| Arkwright Corporate AS | Professional & scientific | 2000 |
| Arkwright Investco 1 AS | Financial services | 2022 |
| Arkwright Norway AS | Professional & scientific | 2005 |
| Arkwright X AS | | 2014 |
| Arkwright X Incubator Invest 10 AS | Financial services | 2019 |
| Arkwright X Incubator Invest 11 AS | Financial services | 2020 |
| Arkwright X Invest 2 AS | | 2025 |
| Arkwright X Invest AS | Financial services | 2021 |
| Arkwright X Management AS | Financial services | 2020 |
| Arkwright X Partners Invest 1 AS | Financial services | 2020 |
| Arkwright X Partners Invest 2 AS | Financial services | 2024 |
| Arkwrightx Incubator Invest 2 AS | Financial services | 2017 |
| Arkwrightx Incubator Invest 3 AS | Financial services | 2017 |
| Arkwrightx Incubator Invest 5 AS | Financial services | 2018 |
| Arkwrightx Incubator Invest 7 AS | Financial services | 2018 |
| Arkwrightx Incubator Invest 8 AS | Financial services | 2018 |
| Arla Foods AS | Wholesale & retail | 1974 |
| Arla Invest AS | | 2021 |
| Arle Invest AS | Financial services | 2006 |
| Arlo Maritime AS | Education | 2009 |
| Arléa Holding AS | Professional & scientific | 2021 |
| Arm-Holding AS | | 2021 |
| Arma Eiendom AS | Real estate | 2005 |
| Armabasito AS | Other services | 2018 |
| Armada Dynamics AS | Information & communication | 2026 |
| Armada Dynamics AS | Information & communication | 1992 |
| Armada Dynamics Holding AS | | 2026 |
| Armada Enterprises AS | Wholesale & retail | 2016 |
| Armadillo AS | Real estate | 1995 |
| Armageddon AS | Hospitality | 2018 |
| Armand Industrier AS | Real estate | 2009 |
| Armann AS | Transport & logistics | 2005 |
| Armarena AS | Real estate | 2001 |
| Armarina AS | Real estate | 2004 |
| Armatech Norway AS | Wholesale & retail | 2026 |
| Armila Holding AS | | 2025 |
| Armile AS | Professional & scientific | 2019 |
| Arminia AS | | 2022 |
| Armita Holding AS | Real estate | 2011 |