| Blåmannsvik - Grøtfjord Utmarkslag SA | Agriculture & fishing | 1999 |
| Blåner Holding AS | | 2019 |
| Blåsebaluba Da | Arts & recreation | 2023 |
| Blåst AS | Manufacturing | 2002 |
| Bme Johnsen AS | Construction | 2012 |
| BMT Eiendom AS | Real estate | 2005 |
| BN Maritim Elektronikk AS | Wholesale & retail | 2025 |
| Bnapp AS | Professional & scientific | 2016 |
| Bnbarctic AS | Real estate | 2026 |
| Bnme AS | Wholesale & retail | 2025 |
| Bo Bra Og Billig AS | Real estate | 2013 |
| Boden Tromsø AS | Wholesale & retail | 2026 |
| Bodyfly Tromsø AS | Health & social care | 2013 |
| Bodø Innovation Gate AS | Real estate | 1966 |
| Bohavet AS | Professional & scientific | 2012 |
| Bok AS | Professional & scientific | 2023 |
| Bokhuset AS | Wholesale & retail | 2021 |
| Bokstavhuset AS | Manufacturing | 1988 |
| Boligbygg Tromsø AS | Construction | 2006 |
| Boliginvest Nord AS | Real estate | 2012 |
| Bondar AS | Construction | 2014 |
| Bondens Marked Troms SA | Professional & scientific | 2004 |
| Bonord Dele AS | Administrative & support | 2022 |
| Bonord Eiendomsmegling AS | Real estate | 2005 |
| Bonord Eiendomsutvikling AS | Real estate | 1992 |
| Bonord Utleieboliger AS | Real estate | 1996 |
| Booking Point AS | Administrative & support | 2023 |
| Bookis AS | Wholesale & retail | 2016 |
| Bookis SPV AS | Financial services | 2023 |
| Boplan AS | | 2018 |
| Borealis Tour AS | Administrative & support | 2025 |
| Borealiz AS | Health & social care | 2014 |
| Borettslaget Conr Holmboes Veg 8-10-12-14 AS | Households | 1954 |
| Borg Maritime AS | Transport & logistics | 2010 |
| Borg Maritime Invest AS | Transport & logistics | 2020 |
| Borkenes Eiendom AS | Real estate | 2022 |
| Bosaa Holding AS | | 2026 |
| Botn AS | Real estate | 2022 |
| Bow Geo AS | Professional & scientific | 2016 |
| Bowling & Squash AS | Wholesale & retail | 2017 |
| Boysen Band AS | Information & communication | 2024 |
| Boysen Trio Da | Arts & recreation | 2019 |
| BP Energi AS | Construction | 2010 |
| Bpa Nord AS | Health & social care | 2007 |
| Bradium AS | Real estate | 2016 |
| Bragde AS | Professional & scientific | 2017 |
| Bramy Eiendom AS | Real estate | 2015 |
| Brandmo Holding AS | | 2024 |
| Brasilimport AS | Wholesale & retail | 2013 |
| Bravo Frisør AS | Other services | 2023 |
| Bread and Wine AS | Hospitality | 2023 |
| Bredbåndsfylket AS | Information & communication | 2003 |
| Breivika Studentbarnehage AS | Education | 2022 |
| Breivika Utvikling AS | Real estate | 2014 |
| Breivikeidet Grunneierlag SA | Administrative & support | 1981 |
| Brelum AS | Health & social care | 2015 |
| Brennbygget AS | Real estate | 1985 |
| Brennbygget Holding AS | | 2026 |
| Briand Consulting AS | Professional & scientific | 2004 |
| Briand Holding AS | Professional & scientific | 2005 |
| Brigg AS | Real estate | 2005 |
| Brillehuset Tromsø AS | Wholesale & retail | 1997 |
| Brim Adventures AS | Administrative & support | 2018 |
| Brim Arctic AS | Professional & scientific | 2018 |
| Brim Explorer AS | Transport & logistics | 2017 |
| Brim Tech AS | Professional & scientific | 2018 |
| Brinksvingen Vel SA | Real estate | 2019 |
| Brokstad Holding AS | Arts & recreation | 2023 |
| Brtech AS | Information & communication | 2017 |
| Brudehuset Tromsø AS | Wholesale & retail | 2012 |
| Brygga Fysioterapi Psykomotorisk Senter Da | Health & social care | 2017 |
| Brygga Næring AS | Real estate | 2023 |
| Brygga Utbygging AS | Real estate | 1931 |
| Bryggekvartalet Tromsø AS | Real estate | 2016 |
| Bryndesign AS | Other services | 2015 |
| Brynjar Invest AS | Hospitality | 2005 |
| Brødrene Echroll AS | Administrative & support | 2019 |
| Brødrene Johannessen AS | Wholesale & retail | 1986 |
| Brødrene Johannessen Invest AS | Wholesale & retail | 2018 |
| Brødrene Sørensen Maskin AS | Construction | 1993 |
| Bskl Invest AS | Professional & scientific | 2011 |
| BSW Consult AS | Professional & scientific | 2023 |
| BTB AS | | 2024 |
| Bubble Tea Tromsø AS | Hospitality | 2021 |
| Bubblegum AS | Real estate | 2020 |
| Bukta Bay AS | Real estate | 2013 |
| Bukta Eiendom AS | Real estate | 2000 |
| Bukta Nord AS | Real estate | 2019 |
| Buldersand AS | Real estate | 2019 |
| Buldreterminalen AS | Arts & recreation | 2022 |
| Bundingen AS | Wholesale & retail | 2010 |
| Burgr Jekta AS | Hospitality | 2024 |
| Burgr Skansen AS | Hospitality | 2016 |
| Burrata AS | | 2019 |
| Business Controlling AS | Arts & recreation | 2017 |
| Butikkdrift E. Solbakken AS | Wholesale & retail | 2023 |
| Butikkdrift Erlandsen AS | Wholesale & retail | 2024 |
| Butikkdrift R13 2 AS | Wholesale & retail | 2019 |
| Butikkdrift Tka AS | Wholesale & retail | 2021 |
| BV Invest AS | | 2024 |