| Blinken Mathus AS | Wholesale & retail | 2001 |
| BLJ Motorsenter AS | Other services | 2013 |
| Blomquist Glass AS | Construction | 2024 |
| Blomquist Transport AS | Transport & logistics | 2000 |
| Blue Pearl AS | Manufacturing | 2010 |
| Bluescreen Da | Hospitality | 2004 |
| Blåseisolering AS | Construction | 2023 |
| BNG Utvikling AS | Professional & scientific | 2016 |
| Bo Hele Livet AS | Information & communication | 2023 |
| Bob Interiørarkitekter AS | Professional & scientific | 2024 |
| Bobra AS | Information & communication | 1995 |
| Bokeløkka Boligutvikling AS | Real estate | 2021 |
| Bol AS | Financial services | 2016 |
| Bolig Og Interiørsenteret AS | Wholesale & retail | 2006 |
| Bommestad Eiendom AS | Real estate | 2008 |
| Bonnegolt Consulting AS | Professional & scientific | 2021 |
| Bonnegolt Holding AS | Professional & scientific | 2015 |
| Borgejordet 80 AS | Real estate | 2005 |
| Borreveien Eiendom AS | Real estate | 2018 |
| Bortskjemt AS | Other services | 2012 |
| Boseko AS | | 2024 |
| Boss Larvik AS | Arts & recreation | 1992 |
| Bostedet AS | Real estate | 2006 |
| Bowo AS | Wholesale & retail | 2020 |
| BPK Norway AS | Information & communication | 2016 |
| Brandbu Montør AS | Construction | 2023 |
| BRANNSIKRING24 AS | Wholesale & retail | 2017 |
| Brannvaktsgata AS | Real estate | 2012 |
| Brannvaktsgate 1 Larvik AS | Real estate | 2020 |
| Brannvaktsgaten 5 AS | Real estate | 1978 |
| Bratlandsbygget AS | Real estate | 2017 |
| Bredal Fysio AS | Health & social care | 2023 |
| Brede Hansen Kran Og Transport AS | Transport & logistics | 2005 |
| Brekke Eiendom AS | Real estate | 2001 |
| Bridgehill AS | Wholesale & retail | 2010 |
| Brief Solutions AS | Professional & scientific | 2020 |
| Britry Holding AS | Health & social care | 2025 |
| Brudesalongen Larvik AS | Wholesale & retail | 2020 |
| Bruket Fritzøe Kontorfellesskap AS | Real estate | 2025 |
| Brum Brum Invest AS | | 2024 |
| Brum Invest Ans | Real estate | 1998 |
| Brunla Allé AS | Real estate | 2018 |
| Brunlanes Eiendom AS | Real estate | 2017 |
| Brunlanes Jordvanning SA | Agriculture & fishing | 1976 |
| Brunlanes Næring AS | Real estate | 2019 |
| Brunlanes Regnskap AS | Professional & scientific | 2020 |
| Brunlanes Royalkapital AS | | 2021 |
| Brunlanes Vekst AS | | 2021 |
| Brunlanesveien 16 AS | Construction | 2010 |
| Bryggekanten Larvik AS | Hospitality | 2005 |
| Bryggerikvartalet Ur Og Smykker AS | Wholesale & retail | 2009 |
| Brynjar Herland AS | Health & social care | 1998 |
| Brynje of Norway AS | Wholesale & retail | 1887 |
| Bråkollen AS | Real estate | 1988 |
| Brødrene Bøk AS | Arts & recreation | 2024 |
| Brødrene Larsen Da | Agriculture & fishing | 1997 |
| Brødrene Lysebo AS | Real estate | 2016 |
| Brødrene Tangen AS | Agriculture & fishing | 2013 |
| BS24 Salg AS | Wholesale & retail | 2018 |
| Bsst Aid AS | Information & communication | 2014 |
| Bsst AS | Wholesale & retail | 2014 |
| Buer Hjelpeselskap AS | Administrative & support | 2022 |
| Bugge Holding AS | Real estate | 1992 |
| Buggesgate 3 AS | Real estate | 2011 |
| Bunadstrikk Da | Professional & scientific | 2021 |
| BWC AS | Administrative & support | 2018 |
| Byens Autosalg AS | Wholesale & retail | 2022 |
| Byens Bilvask AS | Other services | 2018 |
| Byens Trafikkskole AS | Education | 2001 |
| Bygg Det AS | Construction | 2007 |
| Bygg I Betong AS | Construction | 2021 |
| Bygg Og Hage AS | Wholesale & retail | 2017 |
| Byggefirma Vidar Larsen AS | Construction | 2017 |
| Byggfag Proff AS | Wholesale & retail | 2018 |
| Byggfirma Eliassen AS | Construction | 2023 |
| Byggfirma Per Kristian Eliassen AS | Construction | 2017 |
| Byggforum AS | Wholesale & retail | 1991 |
| BYGGINVEST4YOU AS | Real estate | 2015 |
| Byggmester Arne Holhjem AS | | 2005 |
| Byggmester Blikstad AS | Construction | 2010 |
| Byggmester Erik Aasheim AS | Construction | 2005 |
| Byggmester Lindhjem & Lund AS | Construction | 2023 |
| Byggmester Lindhjem AS | Construction | 1998 |
| Byggmester Morten Leinæs AS | Construction | 2002 |
| Byggmester Odd Kristoffersen AS | Construction | 2013 |
| Byggmester Sturle Lindberg AS | Construction | 1988 |
| Byggmester Tom Erik Strøm AS | Construction | 2021 |
| Byggmester Trond Thorstensen AS | Construction | 2020 |
| Byggmester Trulsen AS | Construction | 1997 |
| Byggmesterfirma Jørgensen & Kemkers AS | Construction | 2017 |
| Byggmesterfirmaet Martinsen & Østby AS | Construction | 1998 |
| Byggmesterne Abrahamsen Og Schermann AS | Construction | 2022 |
| Byggservice 123 AS | Construction | 2018 |
| Byggtømrer Norge AS | Construction | 2024 |
| Bergene Holm AS | Manufacturing | 1982 |
| Båtveien AS | Real estate | 2018 |
| Bærtur Invest AS | | 2026 |
| Bøgata 11 AS | Real estate | 1996 |
| Bøkekroa AS | Hospitality | 1979 |
| Bøkekroa Eiendom AS | Real estate | 2003 |