| Backe Idrettsbygg AS | Professional & scientific | 2016 |
| Backe Industri AS | Construction | 2024 |
| Backe Prosjekt AS | Real estate | 2009 |
| Backe Prosjekt Nord AS | Real estate | 2004 |
| Backe Stor-Oslo AS | Construction | 1963 |
| Bahr Holding AS | | 2025 |
| Bahr Innovation AS | Manufacturing | 2025 |
| Bahr Ortopedi AS | Manufacturing | 2025 |
| Bak Bygg AS | Construction | 2026 |
| Balam AS | | 2022 |
| Baldersheim & Aune AS | Real estate | 2007 |
| Bankerød Boliger AS | Real estate | 2016 |
| Barklav (Hong Kong) Limited Nuf | Administrative & support | 2014 |
| Barstølveien 8-12 AS | Real estate | 2023 |
| Battie Geo AS | Real estate | 2007 |
| BB Crewing AS | Transport & logistics | 2007 |
| Bedre Ledelse AS | Education | 2005 |
| Behandlerverket Lysaker AS | Health & social care | 2026 |
| Bei Finans AS | Real estate | 2010 |
| Bel Ship I AS | Transport & logistics | 2013 |
| Bel Ship III AS | Transport & logistics | 2025 |
| Belships Shipholding AS | Transport & logistics | 2019 |
| Belships Shipholding II AS | Transport & logistics | 2021 |
| Belships Shipholding III AS | Transport & logistics | 2025 |
| Belships Trading AS | Transport & logistics | 1993 |
| Bemlotek AS | Professional & scientific | 2015 |
| Benedicte Holding AS | | 2023 |
| Bentec GmbH | Professional & scientific | 1997 |
| Berg Finance AS | Real estate | 2002 |
| Bergensbanen JV Ans | Professional & scientific | 2024 |
| Berger Omlastingssentral AS | Real estate | 2008 |
| Berger/Abam Engineers Inc. | Professional & scientific | 2006 |
| Best Cellars AS | Wholesale & retail | 2001 |
| Bevteam AS | Wholesale & retail | 2025 |
| Bibito AS | Wholesale & retail | 2021 |
| Bibliotekgata 30 AS | Real estate | 2026 |
| Bikeloop AS | Administrative & support | 2021 |
| Bilia JLR Import Norway AS | Wholesale & retail | 2023 |
| BIM2SHARE AS | Information & communication | 2019 |
| Bino Invest AS | | 2018 |
| Biorion Holding AS | | 2023 |
| Birk Assets AS | | 2021 |
| Bitbloom Invest AS | | 2023 |
| Bizdoc-Business Documents AS | Wholesale & retail | 2001 |
| Bjørnerudveien 13 AS | Real estate | 2006 |
| BKS 2 AS | Real estate | 2021 |
| Black Seeds AS | Manufacturing | 2016 |
| Black Sparrow AS | | 2025 |
| Blaksetinvest AS | Professional & scientific | 2016 |
| Blankvann AS | Financial services | 2017 |
| Blastmanager AS | Information & communication | 2006 |
| Blofeld Visuals AS | Professional & scientific | 2016 |
| Blue Energy Partners AS | Professional & scientific | 2025 |
| Bodil Liér AS | Education | 2022 |
| Boi Eiendom AS | Real estate | 2020 |
| Bokhandelens Hus AS | Real estate | 1922 |
| Bolt Communication AS | Professional & scientific | 2009 |
| Bonica AS | Real estate | 2011 |
| Bonntjennsvegen 12-14 AS | Real estate | 2007 |
| Boon Edam AS | Construction | 1986 |
| Boq Invest AS | | 2020 |
| Bordglede AS | Administrative & support | 2018 |
| Borgestad ASA | Real estate | 1904 |
| Borgestad Industries AS | Real estate | 2013 |
| Borgestad Properties AS | Real estate | 1998 |
| Borgestadbakken 2 AS | Real estate | 2012 |
| Boringpeople AS | Information & communication | 2018 |
| Bottleneck Holding AS | Wholesale & retail | 2004 |
| BP Hylle 10 AS | Real estate | 2007 |
| Bracco Imaging Scandinavia AB | Professional & scientific | 2007 |
| Brand Cognition AS | Professional & scientific | 2002 |
| Brand-Box AS | Wholesale & retail | 1994 |
| Brave Leadership AS | Professional & scientific | 2022 |
| Bresto Advokatfirma AS | Professional & scientific | 2024 |
| Bresto AS | Professional & scientific | 2024 |
| Bristol-Myers Squibb Norway AS | Wholesale & retail | 2007 |
| BRJ Golfstubben AS | Real estate | 2020 |
| BRJ Refstad AS | Real estate | 2020 |
| BRJ Voksen AS | Real estate | 2020 |
| Bruco AS | | 2026 |
| Brugata II 19 AS | Real estate | 2018 |
| Brunsbica AS | Financial services | 1996 |
| Bryggeriveien 9 Eiendom AS | Real estate | 2023 |
| Bryggeriveien 9 Invest AS | Real estate | 2023 |
| Bryn Byggteknikk AS | Professional & scientific | 2023 |
| Brynsalleen 6 AS | Real estate | 2000 |
| Brynsalléen 6 KS | Real estate | 2005 |
| Bråtengata 66 AS | Real estate | 2017 |
| Brødrene Jensen AS | Real estate | 1935 |
| Brødrene Jensen Holding I AS | | 2021 |
| Brødrene Jensen Holding II AS | | 2009 |
| Brødrene Jensen Holding III AS | Financial services | 2005 |
| Brødrene Jensen Holding IV AS | Financial services | 2024 |
| Brødrene Jensen Holding V AS | Financial services | 2024 |
| Brødrene Johnsrud AS | Real estate | 1962 |
| BS Jaren AS | | 2019 |
| Bubbledeck Consulting AS | Professional & scientific | 2005 |
| Buksér Og Berging AS | Transport & logistics | 1992 |
| Buoy JV Bidco AS | | 2025 |
| Butikkdrift Gursel Toran AS | Wholesale & retail | 2022 |