| Aluminium Fasader AS | Manufacturing | 1995 |
| Alås AS | Wholesale & retail | 2017 |
| Am Salongen AS | Other services | 2016 |
| Amenat Invest AS | Construction | 2021 |
| Amg Gruppen AS | Manufacturing | 2024 |
| Amundrød Næringspark AS | Agriculture & fishing | 1997 |
| Amurveien Bolig AS | Real estate | 2004 |
| Anda AS | Financial services | 2005 |
| Andebu Boligutvikling AS | Real estate | 2021 |
| Anders Buaas Music AS | Arts & recreation | 2023 |
| Anders Johansen Invest AS | | 2020 |
| Andersen Gruppen AS | Real estate | 2001 |
| Andersen Maletjenester AS | Construction | 2021 |
| Ane Johannessen Nyman Holding AS | | 2023 |
| Ankan AS | Professional & scientific | 2020 |
| Anlegg Stål Og Bygg AS | Construction | 1988 |
| Anleggs-Service AS | Manufacturing | 2004 |
| Anleggsgartner Øst AS | Administrative & support | 2019 |
| Anleggsservice Larvik AS | Construction | 2004 |
| Anmagu AS | | 2024 |
| Anna Sushi & Bubble Tea AS | Hospitality | 2024 |
| Ans Lund Og Randbøl | Hospitality | 1991 |
| Anthoba AS | Real estate | 2005 |
| Antrekkspartner AS | Wholesale & retail | 2024 |
| Anvikveien AS | Real estate | 2022 |
| Ap-Performance Holding AS | Information & communication | 2018 |
| Ap-Performance Solutions AS | Information & communication | 2018 |
| Apaco AS | Information & communication | 2019 |
| Apex Drift AS | Administrative & support | 2026 |
| Aponor AS | Wholesale & retail | 2005 |
| Apponi AS | Other services | 2005 |
| Aps Aluminium Profil Systemer AS | Manufacturing | 1998 |
| Aps Eiendomsselskap AS | Manufacturing | 1983 |
| Aq Konsult AS | Professional & scientific | 2024 |
| Aqua VVS Holding AS | | 2022 |
| Aqua VVS Senteret AS | Construction | 2025 |
| Arbo Consulting AS | Transport & logistics | 2004 |
| Arc Software AS | Information & communication | 2018 |
| Arctic Bolig Partner Da | Construction | 2021 |
| Arg Holding AS | | 2023 |
| Arild Andersen Elektro AS | Construction | 1994 |
| Arild Øyen Invest AS | | 2020 |
| Ariz AS | Professional & scientific | 2022 |
| Arne Helge Steinsholt AS | Construction | 2014 |
| Art Escape AS | | 2002 |
| Artur Solstad Transport AS | Transport & logistics | 2024 |
| Arva Eiendom AS | Construction | 2023 |
| Arve Ståle Olsen AS | Construction | 1988 |
| Aryas Holding AS | | 2023 |
| AS Esab | Wholesale & retail | 1938 |
| AS Kompetansehuset 13A | Professional & scientific | 2022 |
| AS Larvik Shipping | Transport & logistics | 1988 |
| AS Petra | Manufacturing | 2005 |
| AS Torget Parkering | Transport & logistics | 1990 |
| Asiamark AS | | 2020 |
| Asiamark Larvik AS | Wholesale & retail | 2023 |
| Asian Karaoke Og Bar AS | Hospitality | 2020 |
| Asko Vestfold Telemark AS | Wholesale & retail | 1974 |
| Asnorge Com Netthandel Ans | Wholesale & retail | 2000 |
| Aso Invest AS | | 2005 |
| Aspelunden AS | Real estate | 2000 |
| Astrid Software AS | Information & communication | 2022 |
| Astrove AS | Information & communication | 2026 |
| Ate Eiendom AS | Professional & scientific | 2025 |
| Atk Eiendom AS | Construction | 2015 |
| Ato Invest AS | | 2020 |
| Atticum Ans | Information & communication | 1991 |
| Atticum Incubator AS | Information & communication | 2000 |
| Atticum Nettløsninger AS | Information & communication | 2000 |
| Atticum Software AS | Administrative & support | 2002 |
| Audio Design AS | Manufacturing | 1990 |
| Audrius Byggservice AS | Construction | 2013 |
| August Mediestudio AS | Information & communication | 2020 |
| Aunebygget AS | Real estate | 2021 |
| Austein Consulting AS | Professional & scientific | 2017 |
| Austein Gård AS | Agriculture & fishing | 2021 |
| Austein Holding AS | Agriculture & fishing | 2021 |
| Austi Norge AS | Manufacturing | 2004 |
| Aut.Fotterapeut Longva AS | Health & social care | 2017 |
| Auto 3260 AS | Wholesale & retail | 2019 |
| Auto Garantisten AS | Wholesale & retail | 2015 |
| Auto Partner AS | Wholesale & retail | 2026 |
| Autobutikken AS | Wholesale & retail | 2019 |
| Autogalleriet AS | Wholesale & retail | 2017 |
| Autolea AS | Wholesale & retail | 2020 |
| Autoporten AS | Construction | 2014 |
| Autotechnik AS | Other services | 2002 |
| Av Sporet AS | Hospitality | 2019 |
| Aventador Eiendom AS | Real estate | 2023 |
| Avia Ans | | 1990 |
| Avilo AS | Information & communication | 2019 |
| Avilo Services AS | Information & communication | 2012 |
| Avk Holding AS | Professional & scientific | 2018 |
| Avonova Insurance AS | Financial services | 2021 |
| Avonova Midco AS | | 2018 |
| Avonova Solutions AS | Health & social care | 2020 |
| Avonova Solutions BHT AS | Health & social care | 2023 |
| Avonova Solutions Holdco AS | | 2023 |
| Ayres Invest AS | Real estate | 2016 |
| Anglo Import Ans | Wholesale & retail | 1988 |