| Bergmann AS | Real estate | 2021 |
| Bergodd Utvikling AS | Real estate | 2014 |
| Bergsøe AS | Real estate | 2009 |
| Bergum Invest AS | Financial services | 2005 |
| Bergø Eiendom AS | Real estate | 2015 |
| Bernardino AS | Professional & scientific | 1996 |
| Bernd Lach | Manufacturing | 2005 |
| Bernhoff Invest AS | | 2025 |
| Bernt Nordal Holding AS | Wholesale & retail | 2024 |
| Berntsen Mc/Trafikkopplæring AS | Education | 2025 |
| Berntzen Eiendom AS | Real estate | 2009 |
| Berskaughallen AS | Arts & recreation | 2007 |
| Bertram Holding AS | Wholesale & retail | 2005 |
| Beslagteknikk AS | Wholesale & retail | 2005 |
| Bestonåsen AS | Real estate | 2022 |
| Bestonåsen Eiendom AS | Real estate | 2015 |
| Betelkvartalet AS | Real estate | 2017 |
| Betonmast Buskerud-Vestfold AS | Construction | 2013 |
| Betor Drift AS | Wholesale & retail | 2023 |
| Betor Holding AS | Construction | 2019 |
| Better AS | Information & communication | 2015 |
| Bettercallpaal AS | Professional & scientific | 2012 |
| Bevar Våtrom AS | Construction | 2019 |
| Bevisst Kompetanse AS | Health & social care | 2022 |
| Bevisst Naprapati AS | Health & social care | 2017 |
| Bevisstung Bolig AS | Health & social care | 2024 |
| Beyond Tomorrow Ans | Wholesale & retail | 1998 |
| BFP Eiendom AS | Real estate | 2025 |
| BFP Gruppen AS | | 2025 |
| BG Marine AS | Manufacturing | 2021 |
| BGM Eiendom AS | Real estate | 2011 |
| Bibliotekservice AS | Information & communication | 1995 |
| Bichromi Holding AS | | 2020 |
| Big Drum S.L | | 2007 |
| Big Holding AS | Real estate | 2021 |
| Bil & Maskin Drammen Limited Nuf | Wholesale & retail | 2010 |
| Bilan AS | Wholesale & retail | 2021 |
| Bilberries AS | Information & communication | 2020 |
| Bilcom AS | Wholesale & retail | 2000 |
| Bildelekompaniet Ans | | 1994 |
| Bilglass AS | Other services | 2010 |
| Bilkiosken AS | Wholesale & retail | 2024 |
| Bilkosmetikkdrammen AS | Other services | 2025 |
| Billingstadsletta 91 AS | Real estate | 2006 |
| Billity AS | Professional & scientific | 2018 |
| Bilnett AS | Wholesale & retail | 2019 |
| Bilnett Auksjon AS | Wholesale & retail | 2022 |
| Bilpleiespesialisten Drammen AS | Other services | 1997 |
| BILPOINT86 AS | Wholesale & retail | 2025 |
| Bilringen AS | Wholesale & retail | 1973 |
| Bilringen Holding AS | Wholesale & retail | 1998 |
| Bilsalongen AS | Wholesale & retail | 2024 |
| Bilservice Drammen AS | Wholesale & retail | 2020 |
| Bilutstyr Holding AS | Financial services | 2005 |
| Bilvasktek AS | Other services | 2026 |
| Bim Kemi Sweden | Manufacturing | 2013 |
| Bim Norway AS | Manufacturing | 1990 |
| Bima Group AS | Construction | 2020 |
| Binderi Design AS | Wholesale & retail | 1987 |
| Birdiebikes AS | Wholesale & retail | 2024 |
| Birdieskolen AS | Arts & recreation | 2026 |
| Bison TM AS | Administrative & support | 2016 |
| Bit for Bit AS | Information & communication | 1990 |
| Bit for Bit Huset AS | Arts & recreation | 1996 |
| Bit-Ma AS | Financial services | 2017 |
| Biware AS | Information & communication | 1988 |
| Biztec Consult AS | Professional & scientific | 2022 |
| BJ Bil 1 AS | Wholesale & retail | 2022 |
| Bjanka AS | Financial services | 2005 |
| Bjarne Hjelmtvedt Sytilbehør AS | Wholesale & retail | 2007 |
| Bjaro Holding AS | Real estate | 2019 |
| Bjellandveien 24 AS | Real estate | 2004 |
| Bjellandveien 26 AS | Real estate | 2012 |
| Bjerkedok Eiendom AS | Real estate | 2008 |
| Bjerkestrand AS | Real estate | 2005 |
| Bjerknes Eiendom AS | Real estate | 1997 |
| Bjerknes Utvikling AS | Financial services | 2017 |
| Bjøbo AS | Real estate | 2005 |
| Bjørck Invest AS | | 2022 |
| Bjørge Bygg AS | Construction | 2023 |
| Bjørkelund AS | Real estate | 2017 |
| Bjørløw & Bunæs Da | Construction | 1998 |
| Bjørn Boge Rådgivning AS | Professional & scientific | 2014 |
| Bjørn Østby Eiendom AS | Real estate | 2003 |
| Bjørndalstunet Utvikling AS | Real estate | 2022 |
| Bjørnstjerne Bjørnsonsgate 53 AS | Real estate | 2021 |
| Bjøthe AS | Real estate | 2008 |
| BK10 BRL Invest AS | Real estate | 2019 |
| BKB Bolig AS | Real estate | 2011 |
| BKT Tomtebank AS | Real estate | 2021 |
| Bku AS | Real estate | 2010 |
| Black Kite AS | Professional & scientific | 2015 |
| Blackhawk Holding AS | Manufacturing | 1986 |
| BLB Sport AS | Arts & recreation | 2016 |
| Blender Contract AS | Wholesale & retail | 2005 |
| Blestølen Pub Og Cafe AS | Hospitality | 2016 |
| Blichfeldt Transport AS | Transport & logistics | 2002 |
| Blipit AS | Financial services | 2018 |
| Blomsterhaven AS | Real estate | 2003 |
| Blue Beaver AS | Wholesale & retail | 2015 |