| Bygg Og Brannsikring Buskerud AS | Construction | 2013 |
| Bygg Og Pro Service Trondheim AS | Construction | 2025 |
| Bygg Og Våtromsgruppen AS | Construction | 2019 |
| Byggegutta AS | Construction | 2018 |
| Byggesett Hyttelykke AS | Professional & scientific | 2024 |
| Byggmester Akersveen AS | Real estate | 2025 |
| Byggmester Bender AS | Construction | 2018 |
| Byggmester Berntsen AS | Construction | 2016 |
| Byggmester Drammen AS | Construction | 2025 |
| Byggmester Helge Frøiland AS | Construction | 2020 |
| Byggmester Pham VVS & Eiendom AS | Construction | 2007 |
| Byggmestrene Ripel & Svenne AS | Construction | 1990 |
| Byggmestrene Årnes AS | Construction | 1986 |
| Byggservice Og Renhold AS | Administrative & support | 2013 |
| Byggstad MT AS | Construction | 2022 |
| Byrågruppen Heder AS | Other services | 2019 |
| Bugge & Amundsen AS | Administrative & support | 1941 |
| Båtkompetanse AS | Education | 2023 |
| Bøe Eiendomsutvikling AS | Real estate | 2016 |
| Bøeseter Utvikling AS | Real estate | 1964 |
| Bølgen Entertainment AS | Arts & recreation | 2020 |
| Bølstadveien 1 AS | Real estate | 2013 |
| Børge Solem Invest AS | Information & communication | 2017 |
| Børresen Invest AS | Professional & scientific | 2022 |
| Børsen Festlokaler Og Catering AS | Hospitality | 1997 |
| Børsen Tannhelse AS | Health & social care | 2003 |
| Bøto Eiendom AS | Real estate | 2005 |
| Bøvolden Holding AS | Financial services | 2018 |
| C R Invest AS | Professional & scientific | 2008 |
| C&S Holding AS | | 2026 |
| C-Martin Invest AS | | 2022 |
| C-Tec AS | Construction | 2022 |
| C.M.A Holding AS | | 2022 |
| C.S Eiendom AS | Real estate | 2020 |
| C4ISR AS | Information & communication | 2019 |
| Cadoh AS | Other services | 2025 |
| Cadpit AS | Professional & scientific | 2012 |
| Cafè Picasso AS | Hospitality | 2020 |
| Café Sørøst AS | Hospitality | 2022 |
| Cal Eiendom AS | Real estate | 2019 |
| Cal Holding AS | Real estate | 2005 |
| Camilla Halmrast AS | Real estate | 2018 |
| Campino Drammen AS | Hospitality | 2024 |
| Can Import AS | Wholesale & retail | 1978 |
| Candle Art AS | Wholesale & retail | 2003 |
| Canes AS | Wholesale & retail | 1999 |
| Canes Eiendom AS | Real estate | 2019 |
| Canes Holding AS | Wholesale & retail | 2022 |
| Caninus AS | Health & social care | 2023 |
| Cannac Holding AS | Manufacturing | 2021 |
| Capfinera AS | | 2024 |
| Capin AS | Real estate | 2012 |
| Capin Eiendom AS | Real estate | 2012 |
| Cappa Restaurant AS | Hospitality | 2015 |
| Cappelen Eiendom AS | Real estate | 2006 |
| Cappelensgate 24 AS | Real estate | 2018 |
| Capra AS | Financial services | 2013 |
| Capsaicin AS | Professional & scientific | 2025 |
| Capwe AS | Real estate | 2015 |
| Cara AS | Wholesale & retail | 1998 |
| Care Circle AS | Other services | 2023 |
| CARE4COMPANION AS | Education | 2022 |
| Carense Brudekjoler AS | Wholesale & retail | 2023 |
| Cargolink AS | Transport & logistics | 2007 |
| Carlzent AS | Professional & scientific | 2023 |
| Caroline Halmrast AS | Real estate | 2018 |
| Carturn AS | Wholesale & retail | 2009 |
| Casa Clave AS | Manufacturing | 2023 |
| Cash & Drive AS | Other services | 1991 |
| Castillo AS | Other services | 2025 |
| Castrum Eiendom AS | Real estate | 2018 |
| Castrum T2 Invest AS | Real estate | 2019 |
| Castrum T2 Invest II AS | Real estate | 2019 |
| Catapult Film AS | Information & communication | 2022 |
| Catur Holding AS | | 2024 |
| Cavoi AS | | 2024 |
| Cbo Holding AS | Wholesale & retail | 2018 |
| CC Drammen Blomster AS | Wholesale & retail | 2024 |
| CC Lås Og Gravering AS | Other services | 2011 |
| CC Naturkost AS | Wholesale & retail | 1996 |
| CC Parfyme AS | Wholesale & retail | 1986 |
| CC Partner Drammen AS | Administrative & support | 2006 |
| CC Pizza & Grill AS | Hospitality | 2026 |
| CD Tech Capital AS | Manufacturing | 2021 |
| Cdac Holding AS | Real estate | 2019 |
| Cebra Holding AS | Wholesale & retail | 2015 |
| Cel 77 AS | Real estate | 2026 |
| Celand Invest AS | Financial services | 2005 |
| Celi AS | Wholesale & retail | 2020 |
| Celik Invest AS | | 2024 |
| Celimi AS | | 2020 |
| Celli AS | | 2019 |
| Celx AS | | 2021 |
| Cemm Eiendom AS | Real estate | 2014 |
| Cenar AS | Real estate | 2023 |
| Centrum Optikk AS | Wholesale & retail | 1995 |
| Cephalon Norge AS | Administrative & support | 1984 |
| Cern Invest AS | Professional & scientific | 2017 |
| Cevathor AS | Professional & scientific | 2022 |
| Cewatech Norge AS | Professional & scientific | 2018 |