| Blueshift AS | Professional & scientific | 2015 |
| Bluestream Laser Scandinavia AS | Administrative & support | 2022 |
| Blush AS | Wholesale & retail | 2014 |
| Blutek Holding AS | | 2025 |
| Blutek Solutions AS | Information & communication | 2025 |
| BMB Capital AS | | 2024 |
| BMD AS | Real estate | 2009 |
| Bmo Anleggservice AS | Administrative & support | 2015 |
| Bo-Tett AS | Real estate | 2025 |
| BO2 Group AS | Wholesale & retail | 2024 |
| Bog Invest AS | Wholesale & retail | 1996 |
| Boje Pedersen AS | Real estate | 1991 |
| Boke Norway AS | Wholesale & retail | 2007 |
| Bolig Og Hytte Service AS | Administrative & support | 2025 |
| Boligfag AS | Real estate | 2016 |
| Boligkompis AS | Information & communication | 2025 |
| Boligløftet AS | Real estate | 2026 |
| Boligtak AS | Construction | 2025 |
| Bolt Holding AS | Real estate | 2019 |
| Bondegården AS | Wholesale & retail | 2024 |
| Borgegården AS | Real estate | 2018 |
| Borgersen Invest AS | | 2012 |
| Borgeskogen 12 AS | Real estate | 2012 |
| Borgeskogen 17 AS | Real estate | 2007 |
| Borgeskogen 8 AS | Real estate | 2025 |
| Borgeskogen AS | Real estate | 2016 |
| Borgeskogen Metallgjenvinning AS | Water & waste | 2018 |
| Boyer Holding AS | Wholesale & retail | 2023 |
| BP Servicesenter AS | Wholesale & retail | 2015 |
| Brand Connect AS | Wholesale & retail | 2024 |
| Brand Wine Estates AS | Wholesale & retail | 2013 |
| Brande AS | Real estate | 2025 |
| Brann & Kommunikasjonservice Da | Construction | 2000 |
| Brannvaktsgate 8 AS | Real estate | 2008 |
| Brattbakken Vann Og Avløpslag - Drift SA | Water & waste | 2025 |
| Brattbakken Vann Og Avløpslag - Prosjekt SA | Water & waste | 2025 |
| Brattested Engineering AS | Professional & scientific | 2004 |
| Bravo Bygg Og Vedlikehold AS | Construction | 2022 |
| Brdr. Hanssen Da | Administrative & support | 2010 |
| Breakpoint Design AS | Professional & scientific | 2022 |
| Breakthrough Factory AS | Professional & scientific | 2024 |
| Breakwaters AS | Construction | 2011 |
| Breili AS | Hospitality | 2015 |
| Breili Autosalg AS | Wholesale & retail | 2018 |
| Breili Bil AS | Wholesale & retail | 2015 |
| Breili Eiendom AS | Real estate | 2015 |
| Breiliveien 47 AS | Real estate | 2026 |
| Breiliveien 49 AS | Real estate | 2019 |
| Brendhagen Bygg AS | | 2021 |
| Brenna Invest AS | Real estate | 2007 |
| Brentåsen Invest AS | Financial services | 2000 |
| Brettboka AS | Information & communication | 2012 |
| Bridgebuilder Capital AS | | 2020 |
| Brightminds AS | Information & communication | 2019 |
| Brinkmann AS | | 2022 |
| Bris Økonomi AS | Professional & scientific | 2025 |
| Briskebakken Nordre Bryggelag SA | Real estate | 1975 |
| Briskebakken Va-Drift SA | Water & waste | 2024 |
| Briskebakken Va-Prosjekt SA | Real estate | 2024 |
| Briskeveien Eiendom AS | Real estate | 2003 |
| Brit Hunstad AS | Health & social care | 2015 |
| Brittan Snekker Og Hageservice AS | Construction | 2026 |
| Brix Invest AS | Professional & scientific | 2008 |
| Bro Kompetanse AS | Wholesale & retail | 2020 |
| Bro Kompetanse Nuf | Professional & scientific | 2007 |
| Bro Reklame AS | Information & communication | 2011 |
| Brustad Consulting AS | Health & social care | 2019 |
| Bryde Eiendom AS | Real estate | 1998 |
| Brydes Gate 16 Og 18 AS | Real estate | 2018 |
| Brygga 5 Mat Og Vin AS | Hospitality | 2026 |
| Brygga Bar AS | Hospitality | 2010 |
| Brygga-Sandefjord Eiendom Ans | Real estate | 2000 |
| Bryggeriet 1899 AS | Manufacturing | 2025 |
| Bryggestrøm AS | Wholesale & retail | 2012 |
| Brynildsen Invest AS | Construction | 2023 |
| Bryt Bygg AS | Construction | 2021 |
| Bryt Eiendom AS | Real estate | 2021 |
| Bryt Holding AS | Construction | 2021 |
| Brødr Berggren AS | Manufacturing | 2015 |
| Brødr Berggren Eiendom AS | Real estate | 2009 |
| Brødrene Lingelem Ans | Construction | 2000 |
| BS Elektro AS | Construction | 2012 |
| BS Engineering AS | Professional & scientific | 2011 |
| Bs-K AS | Construction | 2015 |
| Bsafe Systems AS | Wholesale & retail | 1999 |
| BSG Family Office AS | Professional & scientific | 2022 |
| BT Engineering AS | Professional & scientific | 2016 |
| Btinvest AS | Wholesale & retail | 1990 |
| BTV AS | Construction | 2002 |
| Buddy Leker AS | Wholesale & retail | 2001 |
| Bueng Holding AS | Financial services | 2005 |
| Buerhagan Va Drift SA | Water & waste | 2026 |
| Bueråsen AS | Real estate | 2017 |
| Bugården Eiendom AS | Real estate | 2024 |
| Bugårdsgata 21 AS | Real estate | 2015 |
| Bukole Holding AS | Financial services | 1987 |
| Bulbul Film AS | Information & communication | 1994 |
| Bull Invest AS | Financial services | 1992 |
| Bundl AS | Professional & scientific | 2024 |
| Buraas Fevang Invest AS | Financial services | 2017 |