| Bad & Våtrom AS | Construction | 2009 |
| Bad & Våtrom Eiendom AS | Real estate | 2020 |
| Badebutikken AS | Wholesale & retail | 1998 |
| Badedesign AS | Construction | 2019 |
| Badhuset AS | Construction | 2005 |
| Badstuggu AS | | 2019 |
| Baf Holding AS | Professional & scientific | 2004 |
| Bag Byhaven AS | Wholesale & retail | 1995 |
| Bag Lade AS | Wholesale & retail | 2014 |
| Bag Leangen AS | Wholesale & retail | 2012 |
| Bag Syd AS | Wholesale & retail | 2023 |
| Bai AS | Financial services | 2013 |
| Baird Holding AS | | 2024 |
| Bait AS | Information & communication | 1997 |
| Baj AS | Professional & scientific | 2023 |
| Bajoto AS | | 1998 |
| Bakeoff AS | Professional & scientific | 2024 |
| Bakeriet 1 AS | Real estate | 2013 |
| Bakerikvartalet AS | Real estate | 2018 |
| Bakery Consult AS | Manufacturing | 2005 |
| Bakgården Bar Og Spiseri AS | Hospitality | 2009 |
| Bakkaunet Eiendom AS | Professional & scientific | 2020 |
| Bakkaunet Tenner Og Kos AS | Health & social care | 2021 |
| Bakke & Frost Da | Construction | 2001 |
| Bakke Tannlegekontor AS | Health & social care | 2006 |
| Bakke-Mannskap AS | Transport & logistics | 2006 |
| Bakkegata 14B AS | Real estate | 2020 |
| Bakkegata 9 AS | Real estate | 2016 |
| Bakkejord Miljøprosjekt AS | Professional & scientific | 2019 |
| Bakken & Magnussen AS | Construction | 2023 |
| Bakken & Magnussen Eiendom AS | Real estate | 2023 |
| Bakken & Magnussen Holding AS | Construction | 2023 |
| Bakken Trafikkskole AS | Education | 2017 |
| Bakklandet Burger AS | Hospitality | 2022 |
| Bakklandet Gjestehus AS | Hospitality | 2026 |
| Bakklandet Interiør Og Boligstyling AS | Professional & scientific | 2017 |
| Bakklandet Invest AS | Real estate | 1996 |
| Bakklandet Ramme & Kunst AS | Manufacturing | 2005 |
| Bakklandet Spesi 1 AS | Other services | 2008 |
| Bakklandsbryggen AS | Real estate | 2008 |
| Baklandet Skydsstation AS | Hospitality | 1996 |
| Bakn Eiendom AS | Real estate | 2022 |
| Balancing Rocks Yoga School AS | Education | 2026 |
| Balanzin AS | Wholesale & retail | 2018 |
| Balder Fornybar AS | Real estate | 2024 |
| Baldershagen AS | | 2025 |
| Ballerin AS | Real estate | 2005 |
| Bamboo Shop AS | Wholesale & retail | 2013 |
| Banegruppen AS | Administrative & support | 2014 |
| Banesikring AS | Professional & scientific | 2022 |
| Bang Investment AS | | 2020 |
| Banjo AS | Information & communication | 2025 |
| Banken Restaurant AS | Hospitality | 2010 |
| Bankeye AS | Information & communication | 2023 |
| Bannthai AS | Other services | 2021 |
| Bao AS | | 2019 |
| Bap Import AS | Wholesale & retail | 2017 |
| Bar Circus AS | Hospitality | 2020 |
| Bar-Dus AS | Hospitality | 2015 |
| Barbarene AS | Hospitality | 2026 |
| Barbecuez-M AS | Hospitality | 2025 |
| Barbecuez-S AS | Hospitality | 2025 |
| Barber&Sons AS | Other services | 2009 |
| Barbier Invest AS | Financial services | 2014 |
| Bare Flyt Trondheim AS | Other services | 2018 |
| Bare Invest Holding AS | Real estate | 2020 |
| Bare IT AS | Information & communication | 2018 |
| Bare Kummer AS | Transport & logistics | 2001 |
| Barek AS | Information & communication | 2005 |
| Baren AS | Hospitality | 2017 |
| Barga AS | Real estate | 2009 |
| Bark Bureau SA | Professional & scientific | 2011 |
| Barnebidrag AS | Professional & scientific | 2015 |
| Barnia AS | Education | 2023 |
| Barnlig SA | Arts & recreation | 2023 |
| Baroni AS | | 2026 |
| Barrel Holding AS | | 2021 |
| Barstein Undervisning AS | Education | 2024 |
| Bart AS | Wholesale & retail | 2017 |
| Bartebyen Holding AS | Information & communication | 2016 |
| Bartebygg AS | Construction | 2024 |
| Bartnes AS | Construction | 1987 |
| Basale Fellesservice AS | Administrative & support | 2015 |
| Basis Bygg AS | Construction | 2002 |
| Basse Holding AS | | 2020 |
| Basseløkka BRL Hjemmel AS | Real estate | 2021 |
| Bastech AS | Professional & scientific | 2005 |
| Batikk House Ans | Wholesale & retail | 2008 |
| Battiq AS | Information & communication | 2025 |
| Bava Holding AS | Real estate | 2005 |
| Baybreeze Holding AS | | 2021 |
| Baz Berg Aktivitet Og Zumbasenter AS | Arts & recreation | 2011 |
| BB Ventures 1 AS | | 2022 |
| BBD AS | Hospitality | 2009 |
| Bbmerk AS | Administrative & support | 2005 |
| Bbno AS | Administrative & support | 2014 |
| BBS Invest AS | | 2018 |
| BC Bygg AS | Construction | 2017 |
| BC Seime AS | | 2026 |
| Bcrescueman AS | Health & social care | 2023 |