| Bingo Sør AS | Arts & recreation | 2007 |
| Biomedika AS | Health & social care | 2020 |
| Birkeland Eiendom AS | Real estate | 1966 |
| Birkeland Gravetjeneste AS | Construction | 2018 |
| Birkenes Transport AS | Transport & logistics | 1992 |
| Birkenlund Eiendom AS | Real estate | 2014 |
| Bjarnes Håndverkstjenester AS | Construction | 2007 |
| Bjornes Bygg AS | Construction | 2024 |
| Bjønneslegene AS | Health & social care | 2023 |
| Bjørn Jensen Invest AS | Real estate | 2021 |
| Bjørnar Invest AS | | 2025 |
| BK Personell Og Eiendomsutvikling AS | Real estate | 2017 |
| Blom Restaurant AS | Hospitality | 2007 |
| Blom-Bakke AS | Wholesale & retail | 2025 |
| Blombird AS | Manufacturing | 2016 |
| Blomsterhjørnet AS | Wholesale & retail | 2021 |
| Blue Technology AS | Professional & scientific | 2018 |
| Blødekjær AS | Real estate | 2006 |
| Blødekjær Eiendom AS | Real estate | 2026 |
| BM Services AS | Construction | 2019 |
| BMM Invest AS | Real estate | 2006 |
| Bodan Invest AS | | 2024 |
| Bogaard Consulting AS | Administrative & support | 2016 |
| Bogaard Invest AS | Professional & scientific | 2023 |
| Boligdrømmen Invest AS | Real estate | 2024 |
| Bonnfara AS | Construction | 2019 |
| Bonsai Snackbar AS | Hospitality | 2022 |
| Bonsai Sushi Arendal AS | Hospitality | 2020 |
| Bonsai Sushi Holding AS | Hospitality | 2020 |
| Borgåsen Utvikling AS | Real estate | 2020 |
| Bosør AS | Real estate | 2022 |
| Bosør Bolig AS | Real estate | 2005 |
| Branden Forvaltning AS | Financial services | 2010 |
| Branden Kapital AS | Financial services | 2010 |
| Branninfo AS | Wholesale & retail | 2022 |
| Brannutstyr AS | Wholesale & retail | 2026 |
| BRC Dekk AS | Wholesale & retail | 2023 |
| Brekke Holding Arendal AS | Real estate | 2005 |
| Brekke Sport AS | Wholesale & retail | 1991 |
| Brekke Sport Holding AS | Wholesale & retail | 2015 |
| Brekkemoen AS | Administrative & support | 2024 |
| Brings AS | | 2014 |
| Brokkr Media AB Nuf | Information & communication | 2025 |
| Bruhagen AS | | 2020 |
| Brusten Holding AS | | 2026 |
| BRV Engineering AS | Manufacturing | 2025 |
| BRV Group AS | | 2025 |
| BRV Inspection AS | Professional & scientific | 2024 |
| Bryggebyen Folkebad AS | Real estate | 2022 |
| Bryggeriveien 4 AS | Real estate | 2013 |
| Bråstad Barnehage AS | Education | 2000 |
| Bråstad Huset AS | Real estate | 2000 |
| Bråstalina AS | Real estate | 2025 |
| Brømnestoppen Maskinstasjon AS | Construction | 2025 |
| Bulder Lekeland AS | Arts & recreation | 2015 |
| Bunnpris Arendal AS | Wholesale & retail | 1993 |
| Bvlarsen Trading AS | Wholesale & retail | 2016 |
| BW Energy Norway Management AS | Professional & scientific | 2022 |
| Bygg Og Tjenester Sjur Vhile AS | Construction | 2026 |
| Bygg Service One AS | Construction | 2017 |
| Byggingeniøren AS | Professional & scientific | 2021 |
| Byggmester Atle Pedersen AS | Construction | 2019 |
| Byggmester Harald Aasbø AS | Construction | 2013 |
| Byggmester Stein R Gundersen AS | Construction | 2017 |
| Byggmester Tellefsen & Christensen AS | Construction | 2022 |
| Byggmester Tellefsen AS | Construction | 2021 |
| BYGGMESTER1 AS | Construction | 2006 |
| Byggpartnere AS | Construction | 2012 |
| Byggpartnere Eiendom AS | Real estate | 2024 |
| Byggpartnere Holding AS | Construction | 2020 |
| Byggpartnere Utvikling AS | Construction | 2020 |
| Byklum Retail AS | Wholesale & retail | 2015 |
| Båthuset Arendal AS | Wholesale & retail | 2019 |
| Bølevegen 4 AS | Real estate | 2020 |
| Bølgen Dansestudio AS | Education | 2012 |
| Bøylestad Energipark AS | Real estate | 2021 |
| Bøylestad Energipark Holding AS | Real estate | 2021 |
| C & C Chiro AS | Health & social care | 2007 |
| C La Vie Klær & Interiør AS | Wholesale & retail | 2010 |
| C Utleie AS | Real estate | 2012 |
| C.Bakke Holding AS | Real estate | 2020 |
| Café Trippel M AS | Hospitality | 2021 |
| Cafériet AS | Hospitality | 2012 |
| Can Systems AS | Professional & scientific | 2014 |
| Canal Street AS | Arts & recreation | 2006 |
| Canal Street Event AS | Arts & recreation | 2020 |
| Carfix Arendal AS | Other services | 2021 |
| Casa Mia Krøgenes AS | Hospitality | 2025 |
| Casmyr AS | | 2016 |
| Caspersensvei 81 AS | Real estate | 2009 |
| Cato Hagane Holding AS | | 2022 |
| CC Berli Kommunikasjon AS | Professional & scientific | 2012 |
| Cefront Invest AS | Professional & scientific | 2020 |
| Cefront Technology AS | Professional & scientific | 2015 |
| Centrum Sør AS | Real estate | 2006 |
| Centrum VVS AS | Construction | 1990 |
| CFF AS | | 2015 |
| CHR TH Boe & Søn AS | Transport & logistics | 1918 |
| Christen Magne Landbø AS | Professional & scientific | 1986 |
| Christiania Eiendom & Invest AS | Real estate | 1999 |