| Bjørg Og Trines Hobbykeramikk Ans | Wholesale & retail | 1994 |
| Bjørklund Jessheim AS | Wholesale & retail | 2004 |
| Bjørn Tores Elektro AS | Construction | 2003 |
| Bjørnrud & Arnestad AS | Wholesale & retail | 2008 |
| Blend & Bean AS | Hospitality | 2024 |
| Blomsteriet AS | Wholesale & retail | 2004 |
| Blomsterstua Jessheim AS | Wholesale & retail | 2023 |
| Blomstre Invest AS | Real estate | 2023 |
| Blå Livredning AS | Education | 2018 |
| Blå Ugle Jessheim AS | Hospitality | 2026 |
| Bobilgruppen AS | Administrative & support | 2026 |
| Bogteh AS | Transport & logistics | 2025 |
| Bolek Konsept AS | Administrative & support | 2026 |
| Boo Service AS | Construction | 2023 |
| Borealis Aero Group AS | Professional & scientific | 2026 |
| Borgen & Dahl Eiendom AS | Construction | 2016 |
| Bowlers Jessheim AS | Hospitality | 2013 |
| Boysenberry AS | Arts & recreation | 2025 |
| Brabo Eie AS | Real estate | 2024 |
| Brabridge AS | Education | 2014 |
| Brannvoll Holding AS | Real estate | 2016 |
| Bratfos Eiendom Og Akustikk AS | Real estate | 2005 |
| Bratfos Holding AS | Real estate | 2005 |
| Bratland Rør AS | Construction | 2023 |
| Brazil Beauty AS | Other services | 2014 |
| Breia Holding AS | | 2024 |
| BREL36 AS | Information & communication | 2015 |
| Brodshaug Invest AS | | 2021 |
| Bruket 2 Utvikling AS | Real estate | 2018 |
| Brumunda Eiendom AS | Real estate | 2018 |
| Brumunddal Boligutvikling AS | Real estate | 2020 |
| Brustad & Partnere AS | Real estate | 2011 |
| Bryllupsinvitasjoner AS | Professional & scientific | 2010 |
| Bråthen Invest AS | Real estate | 2008 |
| Bråthen Rør AS | Construction | 2024 |
| Brødrene Haugesten AS | Other services | 2004 |
| Brødrene Logistikk AS | Transport & logistics | 2023 |
| BSH Transport AS | Transport & logistics | 2022 |
| Bsy AS | Real estate | 2019 |
| BTS Logistikk AS | Construction | 2019 |
| Budbil Og Spedisjon Ans | Transport & logistics | 2001 |
| Bull & Bear Trading AS | Professional & scientific | 2006 |
| Burger & Fries AS | Hospitality | 2021 |
| Business Travel AS | | 1990 |
| Butchers Best AS | Manufacturing | 2022 |
| Bygg & Takst AS | Professional & scientific | 2005 |
| Bygg Din Drøm AS | Construction | 2020 |
| Bygg Og Hageanlegg AS | Construction | 2010 |
| Byggeelementer AS | Construction | 2025 |
| Byggestrøm AS | Real estate | 2008 |
| Byggmester Thomas Borgen AS | Construction | 2023 |
| Byggon AS | Construction | 2026 |
| Byggsmart Kompetanse AS | Professional & scientific | 2025 |
| Byggtjeneste Egvista | Construction | 2004 |
| Bykiropraktoren AS | Health & social care | 2021 |
| Bylegene AS | Health & social care | 2019 |
| Byporten Dagligvare AS | Wholesale & retail | 2021 |
| Byråfinans Invest AS | Professional & scientific | 1986 |
| Bytecapital Ventures AS | | 2023 |
| Bæck Holding AS | Wholesale & retail | 2004 |
| Bøverton AS | Real estate | 2013 |
| C Brynildsen Eiendom AS | Real estate | 1997 |
| C-Grønt AS | Administrative & support | 2021 |
| C3C Engineering AS | Wholesale & retail | 2023 |
| Cafe Mimosa NR. 1 AS | Hospitality | 2025 |
| Caj Invest AS | Real estate | 2019 |
| Caledon Bridge Advisory AS | Professional & scientific | 2025 |
| Calluna AS | Professional & scientific | 2018 |
| Campus 10 AS | Real estate | 2013 |
| Campus 3 AS | Real estate | 2013 |
| Campus 4 AS | Real estate | 2013 |
| Campus 5 AS | Real estate | 2013 |
| Campus 6 AS | Real estate | 2013 |
| Campus 7 AS | Real estate | 2013 |
| Campus 8 AS | Real estate | 2013 |
| Campus 9 AS | Real estate | 2013 |
| Campus Gardermoen AS | Real estate | 2013 |
| Cannuvo Holding AS | | 2019 |
| Capjon Eiendom AS | Administrative & support | 1986 |
| Care Investment AS | Real estate | 2005 |
| Carlab Auto AS | Wholesale & retail | 2021 |
| Carlax Holding AS | Administrative & support | 2020 |
| Catering AS | Hospitality | 2023 |
| Caterings AS | Hospitality | 2026 |
| Cathinka Guldbergs Sykehus AS | Real estate | 2013 |
| Caxia AS | | 2021 |
| Cebra AS | Wholesale & retail | 2021 |
| Cege Reklame AS | Professional & scientific | 2025 |
| Cellaed Scandinavia AS | Administrative & support | 2021 |
| Centrumsgården AS | Real estate | 1984 |
| Centur AS | Professional & scientific | 2022 |
| Cev Holding AS | | 2021 |
| CH2 Holding AS | Real estate | 2011 |
| Chaos Import AS | Wholesale & retail | 2024 |
| Cherry Enterprises AS | Health & social care | 2024 |
| Childrens International School Ski AS | Education | 2020 |
| Christian Walan Da | Administrative & support | 2010 |
| CHÉ Jessheim AS | Hospitality | 2019 |
| Cirrus Arkitekt AS | Professional & scientific | 2017 |
| Closing AS | Professional & scientific | 2014 |