| Dynea Industrier AS | | 2013 |
| Dyngeseth AS | | 2023 |
| Dynje AS | | 2025 |
| Dyno Eiendom Hurum AS | Real estate | 2011 |
| Dyno Eiendom Lillestrøm AS | Real estate | 2011 |
| Dyor AS | Information & communication | 2016 |
| Dyp Dykk AS | Transport & logistics | 2017 |
| Dyp Dykk Invest | | 2015 |
| Dypdykk AS | Information & communication | 2024 |
| Dype Skoger AS | Arts & recreation | 2007 |
| Dypro Eiendom AS | Real estate | 2000 |
| Dypro Holding AS | Real estate | 2005 |
| Dypro Røa AS | Real estate | 1988 |
| Dyr Og Media AS | Wholesale & retail | 2005 |
| Dyrdal Holding AS | | 2024 |
| Dyrebar.No AS | Information & communication | 2021 |
| Dyrebutikken Lambertseter AS | Wholesale & retail | 2025 |
| Dyrebutikken Oslo City AS | Wholesale & retail | 1992 |
| Dyrebutikkenes Servicekontor AS | Professional & scientific | 2022 |
| Dyreid AS | Professional & scientific | 1994 |
| Dyrekjeden AS | Professional & scientific | 2014 |
| Dyresjappa AS | Wholesale & retail | 2006 |
| Dyrgravtoppen AS | Real estate | 2022 |
| Dyrhol Wiker AS | | 2023 |
| Dyrk AS | Professional & scientific | 2020 |
| Dyrk Norsk AS | Agriculture & fishing | 2025 |
| Dyrkselv AS | Education | 2026 |
| Dyrlege Devor AS | Professional & scientific | 2020 |
| Dyrlegene På Torshov AS | Professional & scientific | 2016 |
| Dyrløkke Næringssenter AS | Real estate | 1987 |
| Dyrnes Consulting AS | Professional & scientific | 2013 |
| Dyrskuevegen 22 AS | Construction | 1970 |
| Dyrskuevegen 3 AS | Real estate | 2008 |
| Dyrskuevegen 42 AS | Real estate | 1968 |
| Dyrskuevegen 7 AS | Real estate | 2007 |
| Dyrskueveien 13 Eiendom AS | Real estate | 2022 |
| Dyrskueveien 15 AS | Real estate | 2007 |
| Dyrskueveien 5 Ans | Real estate | 1989 |
| Dyrskueveien 5 AS | Real estate | 2013 |
| Dyrskueveien 5 KS | Real estate | 2013 |
| Dyrstad Studio AS | Professional & scientific | 2026 |
| Dyrt Merke AS | Professional & scientific | 2023 |
| Dyrud Bygg AS | Construction | 2021 |
| Dyrud Holding AS | | 2017 |
| Dyrø AS | | 2025 |
| Dyrø Og Moen AS | Professional & scientific | 2002 |
| Dyrøy Fjordfiske AS | Agriculture & fishing | 2016 |
| Dysleksi Norge Rådgivning AS | Professional & scientific | 2025 |
| Dyson Norway AS | Wholesale & retail | 2016 |
| Dysthe 1 AS | Health & social care | 2002 |
| Dysthe 2 AS | Health & social care | 2002 |
| Dystingbo AS | Administrative & support | 2023 |
| Dystopia Invest AS | Real estate | 2005 |
| Dytt AS | Health & social care | 2006 |
| Dytting Og Holding AS | | 2025 |
| Dyve & Partnere Eiendomsmegling AS | Real estate | 2013 |
| Dyveke AS | Transport & logistics | 1989 |
| Dyveke H AS | | 2023 |
| Dyvi AS | Transport & logistics | 1964 |
| Dyvi Invest AS | Transport & logistics | 2005 |
| Dyvik & Fasting Arkitekter AS | Professional & scientific | 2013 |
| Dampskipsaktieselskapet Østlandet | Transport & logistics | 1915 |
| Den Norske Krigsforsikring for Skib Gjensidig forening | Financial services | 1935 |
| Dårlig Holding AS | | 2018 |
| Dæhlenengen Byggeselskap AS | Households | 1930 |
| Dæhli Bull & Co Advokatfirma Da | Professional & scientific | 1997 |
| Dæhlie-Hyttene AS | Real estate | 1997 |
| Dæhlin Sand Advokatfirma AS | Professional & scientific | 2016 |
| Dælenenga Holding AS | Real estate | 2007 |
| Dælenenga Invest AS | Real estate | 2023 |
| Dælenenggata 24 Ans | Real estate | 2000 |
| Dælenenggata 24 Næring AS | Real estate | 2025 |
| Dælenenggata 38 Butikk AS | Real estate | 2005 |
| Dælenenggata 40 Tomteselskap AS | Real estate | 2009 |
| Dælenenggaten 20 AS | Real estate | 2006 |
| Dære Holding AS | Real estate | 2018 |
| Dæsh AS | Manufacturing | 2026 |
| Döllken Nordic AS | Wholesale & retail | 2014 |
| Dødehavsprodukter Ans | Wholesale & retail | 1999 |
| Døds Diving League AS | Administrative & support | 2021 |
| Døds Holding AS | Professional & scientific | 2012 |
| Døds Holding SPV AS | | 2023 |
| Dødsbohjelpen AS | Administrative & support | 2022 |
| Døgn AS | Professional & scientific | 2019 |
| Døgnservice AS | Construction | 2022 |
| Døgnvakta AS | Construction | 2006 |
| Døla AS | Wholesale & retail | 2014 |
| Døla Takst Og Bygg AS | Real estate | 2025 |
| Dølasletta 5 Holding AS | Real estate | 2021 |
| Dølasletta 5 Property AS | Real estate | 2021 |
| Døli Invest AS | | 2022 |
| Døner Bros Norge AS | Hospitality | 2021 |
| Døner Bros Oslo S AS | Hospitality | 2025 |
| Døner Bros Osterhausgate AS | Hospitality | 2021 |
| Dønnesfjord Vindpark AS | Energy | 2011 |
| Dør Til Dør AS | Transport & logistics | 1992 |
| Dørteknikk AS | Professional & scientific | 2022 |
| Dørum AS | Arts & recreation | 2025 |
| Dørum Gruppen AS | | 2026 |
| Døsserød Gård AS | Real estate | 2022 |