| Aaka AS | Wholesale & retail | 2015 |
| Aanvik Eiendom AS | Real estate | 2003 |
| Activa Kompetanse AS | Professional & scientific | 2014 |
| Advokatfellesskapet Brønnøysund AS | Professional & scientific | 2013 |
| Afs-Invest AS | | 2022 |
| Agrenier AS | Real estate | 2009 |
| Ahsk Holding AS | | 2022 |
| Akva Design Eiendom AS | Real estate | 2019 |
| Akvafuture AS | Agriculture & fishing | 2011 |
| Akvafuture BC AS | Agriculture & fishing | 2022 |
| Akvapartner AS | Wholesale & retail | 2018 |
| Alticon AS | Professional & scientific | 2008 |
| Amazingnor AS | Administrative & support | 2023 |
| Aquaculture Innovation AS | Professional & scientific | 2010 |
| Arctic Mediaservice AS | Professional & scientific | 2008 |
| AS Moheim | | 1971 |
| AS Sparebankbygg | Real estate | 1962 |
| Asiki Eiendom AS | Real estate | 2016 |
| Asker Grill AS | Agriculture & fishing | 2023 |
| Aust Fiskeriselskap AS | Agriculture & fishing | 2019 |
| Bakken Snekkerservice AS | Construction | 2022 |
| Baz Byggeservice AS | Construction | 2024 |
| BBS Invest Brønnøysund AS | Real estate | 2018 |
| Bellavista 308 AS | Real estate | 2008 |
| Bendiksen Eiendom AS | Real estate | 2015 |
| Bendiksen Entreprenør AS | Construction | 2012 |
| Bernard Martinsen Elektro AS | Construction | 2000 |
| Beverlys Hill AS | Administrative & support | 2019 |
| BG Invest Brønnøysund AS | Real estate | 2011 |
| Bil & Teknikk Da | Other services | 2005 |
| Bjørn Helge Reitan AS | Construction | 2012 |
| BKF Invest AS | Financial services | 2016 |
| Blomsterbutikken AS | Wholesale & retail | 2023 |
| Bohrium AS | | 2022 |
| Braks AS | | 2026 |
| Brattland Eiendom AS | Real estate | 2018 |
| Brattland Holding AS | Wholesale & retail | 2018 |
| Brel Eiendom AS | Real estate | 2020 |
| Brillehuset Brønnøysund AS | Wholesale & retail | 2011 |
| Brækkans Ekspedisjon AS | Transport & logistics | 1987 |
| Brækkans Skipsekspedisjon AS | Transport & logistics | 2021 |
| Bröd AS | Manufacturing | 2024 |
| Brønnøen Holding AS | Construction | 2001 |
| Brønnøen Holding Eiendom AS | Construction | 2012 |
| Brønnøy Arbeidsklærsenter AS | Wholesale & retail | 2004 |
| Brønnøy Aviation AS | Administrative & support | 2018 |
| Brønnøy Barneteater | Arts & recreation | 2012 |
| Brønnøy Brannservice AS | Professional & scientific | 2021 |
| Brønnøy Bygg & Bolig AS | Construction | 2013 |
| Brønnøy Bygg AS | Construction | 2014 |
| Brønnøy Bygg Og Eiendom Ans | Manufacturing | 1998 |
| Brønnøy Farming AS | Professional & scientific | 2017 |
| Brønnøy Fiskemottak AS | Real estate | 2003 |
| Brønnøy Fiskeriselskap AS | Agriculture & fishing | 2002 |
| Brønnøy Fysio AS | Health & social care | 2025 |
| Brønnøy Fysioterapi AS | Real estate | 2019 |
| Brønnøy Ga-Hangar AS | Real estate | 2014 |
| Brønnøy Gartneri AS | Agriculture & fishing | 2021 |
| Brønnøy Kranservice AS | Education | 1979 |
| Brønnøy Kystfiske AS | Agriculture & fishing | 2013 |
| Brønnøy Lagerhotell AS | Transport & logistics | 2015 |
| Brønnøy Landbrukstjenester SA | Agriculture & fishing | 1995 |
| Brønnøy Leven Og Bowling AS | Arts & recreation | 2026 |
| Brønnøy Pubdrift Ans | Hospitality | 1997 |
| Brønnøy Regnskap AS | Professional & scientific | 2018 |
| Brønnøy Service Og Distribusjon AS | Transport & logistics | 2020 |
| Brønnøy Trafikkskole AS | Education | 2017 |
| Brønnøy Veterinærklinikk AS | Professional & scientific | 2021 |
| Brønnøyosen Båtlag SA | Other services | 2006 |
| Brønnøysund Bok Og Papirhandel AS | Wholesale & retail | 1997 |
| Brønnøysund Elektriske AS | Construction | 2012 |
| Brønnøysund Elektriske Eiendom AS | Real estate | 1998 |
| Brønnøysund Golfsenter AS | Arts & recreation | 2026 |
| Brønnøysund Grill AS | Hospitality | 2024 |
| Brønnøysund Lavpris AS | Wholesale & retail | 1998 |
| Brønnøysund Rør AS | Construction | 1979 |
| Brønnøysund Skomagasin A/S | Wholesale & retail | 1988 |
| Brønnøysund Taxi AS | Transport & logistics | 1996 |
| Brønnøysunds Avis AS | Information & communication | 2001 |
| Busch AS | | 2021 |
| Bygg Gros Entreprenør AS | Construction | 2016 |
| Bygg Tech Forvaltning Brønnøysund AS | Real estate | 2005 |
| Bygg Tech Siv.Ing. Svein Ebbe Nielsen Siv.Ing. Sigbjørn Gladsø AS | Professional & scientific | 1991 |
| Byggdrift Og Utleie Brønnøysund AS | Administrative & support | 2024 |
| Byggetun Eiendom AS | Real estate | 2012 |
| Byggetun Holding AS | Real estate | 2021 |
| Campus Blå AS | Education | 2017 |
| Campus Blå Fagskole AS | Education | 2017 |
| Campus Blå Folkehøgskole AS | Education | 2021 |
| Campus Blå Videregående Skole AS | Education | 2017 |
| Cash Bar AS | Hospitality | 2022 |
| Cash Barber AS | Other services | 2022 |
| Cash Beauty AS | Other services | 2025 |
| Ciffer AS | Professional & scientific | 2020 |
| Cmhi AS | Real estate | 1987 |
| Codfarm AS | Agriculture & fishing | 2017 |
| Coop Sør-Helgeland Eiendom AS | Real estate | 2009 |
| Corner Hotell AS | Hospitality | 1964 |
| Creo Service SA | Administrative & support | 2010 |
| Den Glade Sjåfør AS | Transport & logistics | 2021 |