| Blackbird AS | Professional & scientific | 2008 |
| Blackbird Music AS | Arts & recreation | 2014 |
| Blackfish Capital AS | Financial services | 2016 |
| Blackfjrd AS | Professional & scientific | 2026 |
| Blackfriars Capital Management AS | Financial services | 1994 |
| Blackfriars Shipping Co Ltd | Transport & logistics | 1995 |
| Blackpearl AS | | 2026 |
| Blackwolf Dynamics AS | Financial services | 2014 |
| Blad AS | Wholesale & retail | 2009 |
| Bladbete Holding AS | | 2023 |
| Bladcentralen AS | Transport & logistics | 2019 |
| Blade Studio Røa AS | Other services | 2019 |
| Blade Studio Skøyen AS | Other services | 2019 |
| Bladeco Financial Group Limited | Real estate | 2020 |
| Blair Bygg AS | Construction | 2011 |
| Blairhel Invest AS | | 2020 |
| Blake AS | Professional & scientific | 2015 |
| Blakkrock AS | | 2025 |
| Blakshaugen AS | Real estate | 2001 |
| Blakshaugen Eiendom AS | Real estate | 2000 |
| Blakstad Haffner AS | Professional & scientific | 2014 |
| Blakstad Horisont AS | Real estate | 2025 |
| Blakstad Utvikling AS | Real estate | 2025 |
| Blakstvedt Holding AS | | 2023 |
| Blanch AS | Hospitality | 2018 |
| Blanco Holding AS | | 2025 |
| Blancodor AS | Health & social care | 2022 |
| Blank AS | Information & communication | 2015 |
| Blank Blank AS | Professional & scientific | 2020 |
| Blank Og Matt AS | Construction | 2021 |
| Blanken AS | Real estate | 2010 |
| Blankenborg AS | Financial services | 2018 |
| Blanks AS | | 2019 |
| Blankscapes Design AS | Professional & scientific | 2014 |
| Blanq AS | Professional & scientific | 2022 |
| Blaser Group Norway AS | Wholesale & retail | 2020 |
| Blaster Services Ltd Nuf | Manufacturing | 2024 |
| Blastr Green Steel (Norway) AS | Professional & scientific | 2025 |
| Blastr Green Steel AS | Professional & scientific | 2021 |
| Blatch Consult AS | Professional & scientific | 2025 |
| Blauenfeldt AS | Professional & scientific | 2026 |
| Blazej Holding AS | Construction | 2020 |
| Blazevic Investments Ans | Real estate | 2007 |
| BLC Agency AS | Professional & scientific | 2024 |
| BLC AS | Transport & logistics | 2007 |
| BLC Holding AS | Financial services | 2022 |
| BLC Invest AS | Professional & scientific | 2016 |
| Blco Drift AS | Real estate | 2016 |
| BLD Wines AS | Wholesale & retail | 2025 |
| Bldn Holding AS | | 2024 |
| Bleed AS | Professional & scientific | 2000 |
| Bleeding Edge Technologies Ltd Nuf | Information & communication | 2009 |
| Blef AS | Wholesale & retail | 2025 |
| Bleikfjell AS | | 2018 |
| Bleiksøya 4 AS | Real estate | 2020 |
| Bleivik Holding AS | Professional & scientific | 2005 |
| Bleka Gruber AS | Mining & quarrying | 1936 |
| Bleke Invest AS | Real estate | 2017 |
| Blekkcompagniet AS | Wholesale & retail | 2002 |
| Blekkis AS | Arts & recreation | 2024 |
| Blekksprut AS | | 2022 |
| Blekksprut Invest AS | | 2019 |
| Blekksprut'N Risotrykkeri SA | Manufacturing | 2024 |
| Blend Wines AS | Wholesale & retail | 2006 |
| Blenda Art AS | Information & communication | 2026 |
| Blender 360 AS | Wholesale & retail | 2025 |
| Blender Agency AS | Wholesale & retail | 2004 |
| Blender AS | Hospitality | 2002 |
| Blender Brands AS | Professional & scientific | 2017 |
| Blender Holding AS | Wholesale & retail | 2005 |
| Blender Partners AS | Professional & scientific | 2017 |
| Blends Ventures AS | | 2023 |
| Blendtech AS | | 2024 |
| Bleq AS | Manufacturing | 2023 |
| Blert Invest AS | | 2018 |
| Blestereggen AS | | 2025 |
| BLF Holding AS | Wholesale & retail | 2016 |
| Bli Ansatt AS | Information & communication | 2026 |
| Bli Lyd AS | Arts & recreation | 2022 |
| Blich Holding AS | | 2025 |
| Blicher AS | Professional & scientific | 2018 |
| Blick Holding AS | Financial services | 2017 |
| Blid AS | Health & social care | 2019 |
| Blid Holding AS | Health & social care | 2019 |
| Blid Mipco AS | | 2020 |
| Blikk Arkitektur AS | Professional & scientific | 2020 |
| Blikk AS | Information & communication | 1991 |
| Blikk Boligfoto AS | Manufacturing | 2025 |
| Blikk Invest AS | Administrative & support | 1992 |
| Blikk Øyeklinikk AS | Health & social care | 2013 |
| Blikkboks Ltd Nuf | Wholesale & retail | 2003 |
| Blikkenslager Breen AS | Construction | 2021 |
| Blikkenslagermester Lars Eriksen AS | Construction | 2018 |
| Blikkenslagermesteren Entreprenør AS | Construction | 2010 |
| Blikkenslagermesterne AS | Construction | 2026 |
| Blikkenslagermestrene Henry Hansen & Sønn AS | Construction | 1966 |
| Bliks Holding AS | Construction | 2023 |
| Bliksfjorden Invest AS | Financial services | 2006 |
| Blikufjellseter Skog Ans | Agriculture & fishing | 2006 |
| Blinc SA | Arts & recreation | 2023 |