| Arne Nielsen Eiendom AS | Real estate | 2005 |
| Arne Rudjord AS | Real estate | 2005 |
| Arrow Head AS | Wholesale & retail | 2013 |
| Ars Capital AS | Information & communication | 2025 |
| Artsafe AS | Real estate | 2002 |
| AS Drivaksel | Professional & scientific | 2022 |
| AS Mineral | Real estate | 1968 |
| AS Nordens Nyheter | Information & communication | 1991 |
| AS Norsk Papirbaandfabrik | Real estate | 1935 |
| AS Optifit Health | Health & social care | 2024 |
| AS Watt | Construction | 1990 |
| Assetfinance AS | Wholesale & retail | 2025 |
| Astriga AS | | 1995 |
| At Sturk AS | Wholesale & retail | 2013 |
| At-Geofence AS | Information & communication | 2026 |
| Ats AS | Real estate | 2020 |
| Ats Next AS | Real estate | 2016 |
| Atw Holding AS | Health & social care | 2022 |
| Aucotec Norway AS | Information & communication | 2020 |
| Austnes Holding AS | Professional & scientific | 2020 |
| Auto Bilsalg AS | Wholesale & retail | 2022 |
| Auto Tjuvholmen AS | Wholesale & retail | 2011 |
| Autona AS | Wholesale & retail | 2023 |
| Ava Security AS | Information & communication | 2016 |
| Avalanche Holding AS | | 2021 |
| Avalon Holding AS | Real estate | 2012 |
| Average Capital AS | | 2026 |
| Average Joe Incorporated AS | Wholesale & retail | 2016 |
| Aw S1 AS | Real estate | 2021 |
| Axiom AS | | 2022 |
| Axxelerator 14 AS | | 2026 |
| Axxelerator AS | Wholesale & retail | 2020 |
| B Consult Prosjekt AS | Professional & scientific | 2007 |
| B Sund Holding AS | | 2023 |
| Baldershage AS | Real estate | 2020 |
| Bare Leven AS | Real estate | 2019 |
| Barfi & Co. AS | Manufacturing | 2012 |
| Barnes Scandinavia AS | Real estate | 2008 |
| Bassengdrift AS | Arts & recreation | 2008 |
| Batch NO7 AS | Wholesale & retail | 2012 |
| Baxterstorey Norway AS | Hospitality | 2011 |
| BC Holding AS | Education | 2004 |
| Bebeka AS | Financial services | 2005 |
| Behandlerverket AS | Health & social care | 2022 |
| Behandlerverket Fornebu AS | Health & social care | 2022 |
| Behandlerverket Holding AS | Health & social care | 2022 |
| Beret AS | Wholesale & retail | 2015 |
| Bergfjord AS | Financial services | 2005 |
| Better Projects AS | Professional & scientific | 2010 |
| BGB Consulting AS | Professional & scientific | 2012 |
| Bharga AS | | 2019 |
| Bianca Eiendom AS | Real estate | 2019 |
| Big Black Holding AS | Real estate | 2021 |
| Bil Byrået AS | Wholesale & retail | 2024 |
| Bilflipp AS | Education | 2022 |
| Bio Energy AS | Energy | 2004 |
| Biogrid AS | Manufacturing | 2015 |
| Biosort AS | Professional & scientific | 2010 |
| Bjerch Golf AS | Arts & recreation | 2008 |
| Bjørn Sund Invest 2 AS | | 2023 |
| Bjørnenga AS | | 2023 |
| Bjørvika Ikt AS | Information & communication | 2006 |
| Bki Holding AS | | 2021 |
| BKV Eiendom AS | Real estate | 2005 |
| Bldng.Ai AS | Information & communication | 2021 |
| Blender Agency Kids AS | Wholesale & retail | 2010 |
| Blomqvist Kunsthandel AS | Wholesale & retail | 2013 |
| Blomqvist Nettauksjon AS | Wholesale & retail | 1939 |
| Bluconsulting AS | Professional & scientific | 2026 |
| Bluehill Holding AS | | 2023 |
| Blåtur AS | Financial services | 2024 |
| BMW Financial Services Scandinavia Nuf | Financial services | 1999 |
| BMW Norge AS | Wholesale & retail | 1994 |
| Bonum Spirits AS | Wholesale & retail | 2021 |
| Bonum Wine & Spirits AS | Wholesale & retail | 2021 |
| Bonum Wine AS | Wholesale & retail | 2016 |
| Borgen Utvikling Bolig AS | Real estate | 2015 |
| BQ Drift AS | Information & communication | 2019 |
| Brand Store Holding AS | Wholesale & retail | 2003 |
| Breia Invest AS | | 2025 |
| Brem Holding AS | Financial services | 2018 |
| Brookhaven Instruments AB Nuf | Wholesale & retail | 2005 |
| Bruun & Stengade Norge AS | Wholesale & retail | 2009 |
| Brysik Industries AS | Professional & scientific | 2023 |
| Brødrene London AS | Real estate | 2015 |
| BTX Norge AS | Wholesale & retail | 1977 |
| Bucky Payments AS | Information & communication | 2016 |
| Busma AS | | 2022 |
| Butikkdrift Ismaeel Abbas AS | Wholesale & retail | 2024 |
| Buysure Rec AS | | 2019 |
| BVF Holding AS | | 2019 |
| Bwell Norge AS | Wholesale & retail | 2008 |
| Bwell Walking AS | Wholesale & retail | 2011 |
| Byggdriften Forvalt AS | Real estate | 2025 |
| Byggdriften.No AS | Administrative & support | 2024 |
| Bærum Byggtjenester AS | Construction | 2011 |
| Bærum Kunsthall AS | Administrative & support | 2016 |
| Bøle Vekst AS | Real estate | 2004 |
| Børsa Holding AS | | 2019 |
| C-It AS | Information & communication | 2016 |