| Blind Archery Club Da | Arts & recreation | 2005 |
| Blind Spot Holding AS | Wholesale & retail | 2017 |
| Blinder AS | Information & communication | 2024 |
| Blindern Barnestuer SA | Education | 1992 |
| Blindern Bok AS | Information & communication | 2026 |
| Blindern Mat AS | Wholesale & retail | 2020 |
| Blindern Trafikkskole AS | Education | 2018 |
| Blindern Utvikling AS | Real estate | 2022 |
| Blindernveien - Sio Barnehage AS | Education | 2022 |
| Blindspot AS | Information & communication | 2021 |
| Blindt Da | Information & communication | 2020 |
| Bling Automated AS | Professional & scientific | 2023 |
| Blink Communications AS | Professional & scientific | 2017 |
| Blink Invest AS | | 2024 |
| Blink Media AS | Information & communication | 2012 |
| Blinky AS | Wholesale & retail | 2025 |
| Blinq AS | Information & communication | 2015 |
| Blipdip AS | Information & communication | 2024 |
| Bliss Beauty AS | Other services | 2024 |
| Bliss Blomst AS | Wholesale & retail | 2017 |
| Bliss Consept AS | Other services | 2007 |
| Blit AS | Information & communication | 2025 |
| Blito AS | Real estate | 1995 |
| Blitzbox AS | Professional & scientific | 2015 |
| Blitzner / Møller Holding AS | | 2017 |
| Blix AI AS | Information & communication | 2026 |
| Blix Boligutvikling AS | Real estate | 2020 |
| Blix Data Center AS | Information & communication | 2014 |
| Blix Group AS | Information & communication | 2012 |
| Blix Invest AS | | 2020 |
| Blix Solutions AS | Information & communication | 2008 |
| Blix Werner Holding AS | | 2022 |
| Blixen Invest AS | Real estate | 2007 |
| Blixt Geo AS | Professional & scientific | 2019 |
| Blixtelliani AS | | 2020 |
| Blizzard AS | Administrative & support | 2020 |
| BLK Drift AS | Wholesale & retail | 2019 |
| Bloc AS | Information & communication | 2005 |
| Bloc Drift AS | Information & communication | 2013 |
| Blockandinavia AS | Information & communication | 2018 |
| Blockandinavia Holding AS | | 2017 |
| Blockchain Technology AS | | 2018 |
| Blodkvalt Da | Arts & recreation | 2023 |
| Blodsbrødre Ans | Arts & recreation | 2004 |
| Blodtype Pinot Og Nebbiolo AS | | 2020 |
| Blodøks AS | | 2025 |
| Bloemendaal Holding AS | | 2024 |
| Blokhus Invest AS | | 2026 |
| Blokk Arkitekter AS | Professional & scientific | 2009 |
| Blokk AS | Real estate | 2021 |
| Blokk Invest AS | | 2022 |
| Blokka Holding AS | Hospitality | 2024 |
| Blokkebukta Og Øygarden Vann Og Avløpsdriftsforetak SA | Real estate | 2019 |
| Blokkfabrikktomta AS | Real estate | 2018 |
| Blokksberg AS | Information & communication | 2024 |
| Blokmar AS | Professional & scientific | 2018 |
| Bloksberg Technologies AS | Information & communication | 2021 |
| Bloksbjerg Regnskap AS | Professional & scientific | 2021 |
| Blom Boligeiendom 1 AS | Real estate | 2023 |
| Blom Boligeiendom 2 AS | Real estate | 2023 |
| Blom Consulting AS | Administrative & support | 2016 |
| Blom Investering AS | | 2012 |
| Blom Kapital AS | | 2025 |
| Blom Maritime AS | Professional & scientific | 2014 |
| Blom Og Vom AS | Real estate | 2010 |
| Blom-Invest AS | Professional & scientific | 2024 |
| Blomberg Holding AS | | 2025 |
| Blome AS | Wholesale & retail | 2018 |
| Blomeslettane AS | Professional & scientific | 2018 |
| Blomgren Consulting AS | Information & communication | 2020 |
| Blomgren Holding AS | Information & communication | 2020 |
| Blomgren Isaksen Marketing Ans | Wholesale & retail | 1995 |
| Blominor AS | Wholesale & retail | 2026 |
| Blommenholm Industrier AS | Information & communication | 2008 |
| Blommenholm Terrasse AS | Construction | 2020 |
| Blommenholmveien 1 AS | Real estate | 2009 |
| Blomqvist AS | Wholesale & retail | 2005 |
| Bloms Oppmåling AS | Financial services | 2015 |
| Blomst Af Hansen AS | Wholesale & retail | 2006 |
| Blomst Da | Arts & recreation | 2022 |
| Blomster Renhold AS | Administrative & support | 2022 |
| Blomsterdalen Bolig AS | Real estate | 2012 |
| Blomsterdekoratøren Fyrstikktorget AS | Wholesale & retail | 2005 |
| Blomsterelsker Da | Administrative & support | 2024 |
| Blomsterengen AS | Information & communication | 2016 |
| Blomsterhagen På Abildsø AS | Agriculture & fishing | 2013 |
| Blomsterimport AS | Wholesale & retail | 2014 |
| Blomsterista AS | Wholesale & retail | 2021 |
| Blomsterkraft AS | Arts & recreation | 2014 |
| Blomstermarked AS | Wholesale & retail | 2022 |
| Blomsterpikenes Verden AS | Wholesale & retail | 2006 |
| Blomstertorget Oslo AS | Administrative & support | 2024 |
| Blomstrand Holding AS | Arts & recreation | 2020 |
| Blomstrøm Holding AS | | 2025 |
| Blomstølen Invest AS | Real estate | 2020 |
| Blonde by Catharina AS | Other services | 2022 |
| Blonde Studio AS | Other services | 2024 |
| Blondes AS | Wholesale & retail | 2013 |
| Blondr AS | Information & communication | 2024 |
| Blood & Thunder AS | | 2022 |