| Are Bekkelund AS | Professional & scientific | 2019 |
| Arifagic Eiendom AS | Real estate | 2008 |
| Arifagic Investment Utland AS | Wholesale & retail | 2011 |
| Arkart AS | Professional & scientific | 2024 |
| Arkart. Da | Professional & scientific | 2020 |
| Arne Haugom AS | Real estate | 1976 |
| Arne Lundstad Holding AS | Education | 2005 |
| Arnhild AS | Real estate | 2018 |
| Aroma K AS | Wholesale & retail | 2023 |
| Arstuen AS | Real estate | 2014 |
| Art-Deco AS | Wholesale & retail | 2016 |
| Art-Deco Holding AS | Wholesale & retail | 2016 |
| Artikolor AS | Arts & recreation | 2021 |
| AS Byggtjenester | Construction | 1986 |
| AS Gjøvik Skofabrik | Real estate | 1916 |
| AS Gtk-Hallen | Real estate | 1986 |
| AS Hverdag M.M. | Hospitality | 2024 |
| AS Oplandske Dampskibsselskap | Transport & logistics | 1852 |
| AS Oppland Arbeiderblad | Information & communication | 1982 |
| AS Parterre | Real estate | 1979 |
| AS Prinsensgate 14 | Real estate | 1976 |
| Ask 42 AS | Health & social care | 2023 |
| Aslak Boltsgate Eiendom AS | Real estate | 2005 |
| Asle Brækken Invest | | 2022 |
| Asteko AS | Real estate | 1999 |
| Atelièr M AS | Other services | 2019 |
| Atlantis Holding AS | Education | 2005 |
| Atlas Industri AS | Manufacturing | 1984 |
| Augustas Kafe Da | Hospitality | 2001 |
| Autoimport AS | Wholesale & retail | 1997 |
| Automar AS | Wholesale & retail | 2023 |
| Aventus Holding AS | | 2022 |
| Avero Partners AS | Professional & scientific | 2022 |
| Avisomo AS | Professional & scientific | 2018 |
| Awanz AS | Wholesale & retail | 2023 |
| Awo Holding AS | Real estate | 2021 |
| Axi Hedmark & Oppland AS | Wholesale & retail | 2014 |
| Azul Del Mar AS | Real estate | 2013 |
| B&K Bygg AS | Construction | 2023 |
| B-Ma Invest AS | | 2019 |
| B. Lie Holding AS | Financial services | 2017 |
| B36 Tomteutvikling AS | Real estate | 2020 |
| Backe Eiendom AS | Real estate | 1987 |
| Backe Invest AS | Financial services | 2005 |
| Backe Retail AS | Wholesale & retail | 2007 |
| Bae Systems Hägglunds AB Nuf | Wholesale & retail | 2005 |
| Bag Nordic AS | Wholesale & retail | 2019 |
| Bahrdal AS | Professional & scientific | 1993 |
| Baila Oslo AS | Wholesale & retail | 2026 |
| Bakerihjørnet Eiendom AS | Real estate | 2006 |
| Bakke Eiendom Ans | Real estate | 1993 |
| Bakke El-Installasjon AS | Construction | 1989 |
| Bakkegata 1 Gjøvik Da | Real estate | 2005 |
| Bakkegata 3 Ans | Real estate | 1995 |
| Bakstekjellern AS | Hospitality | 2024 |
| Bamsedyra AS | Wholesale & retail | 2025 |
| Bardu Butikkeiendom AS | Real estate | 2018 |
| Bare Brød AS | Manufacturing | 2012 |
| Bare Trond AS | Professional & scientific | 2005 |
| Barokksolistene AS | Arts & recreation | 2010 |
| Basic Gym AS | Arts & recreation | 2007 |
| Bassengparken Eiendom AS | Real estate | 2015 |
| Bbbv AS | | 2020 |
| BCK Invest AS | | 2020 |
| Beckback AS | Professional & scientific | 2023 |
| Bekkevolds Lyskopi AS | Manufacturing | 2023 |
| Bemanningstjenester Gjøvik AS | Administrative & support | 2007 |
| Benoerik AS | | 2021 |
| Bensaid Holding AS | Real estate | 2005 |
| Berg Panorama AS | Real estate | 2017 |
| Berg&Boe Da | Wholesale & retail | 2022 |
| Bergjarl Holding AS | Health & social care | 2005 |
| Bergum & Skogli Oljeservice AS | Wholesale & retail | 2013 |
| Bergvegen 2 AS | Real estate | 2016 |
| Bertelsen Holding AS | | 2011 |
| Betera AS | Information & communication | 2021 |
| Betonmast Innlandet AS | Construction | 2002 |
| Big Red Holding AS | | 2022 |
| Bil & Lyd AS | Wholesale & retail | 2020 |
| Bilitt Bygg & Bolig AS | Real estate | 2020 |
| Biljarddrift AS | Information & communication | 2026 |
| Bilskadesenteret Gjøvik AS | Other services | 2005 |
| Bing Holding AS | Real estate | 1999 |
| Bio Invest AS | Real estate | 2010 |
| Bio Vann Og Helse AS | Wholesale & retail | 1990 |
| Biolin AS | Professional & scientific | 2024 |
| Biolin Eiendom AS | Real estate | 2024 |
| Biri Mølle AS | Real estate | 2020 |
| Birkstack AS | | 2026 |
| Bismo Takst AS | Real estate | 2022 |
| Bjerke Butikkeiendom Oslo AS | Real estate | 2011 |
| Bjørkestien Holding AS | Financial services | 2005 |
| Bjørlo Holding AS | Financial services | 2015 |
| Bjørn Bratlie AS | Real estate | 1983 |
| Bjørnerabatten Ans | Wholesale & retail | 1998 |
| Bjørnerud AS | Real estate | 1985 |
| Bjørnetjenester AS | | 2023 |
| Bjørnsons Gate 5 AS | Real estate | 2021 |
| Bjørnsonsgate 2 AS | Real estate | 2021 |
| Bjørnsonsgate 6 AS | Real estate | 1995 |