| Hobbelstad AS | Construction | 2005 |
| Hobbelstad Og Rønning AS | Construction | 1972 |
| Hoen Fjernvarme Da | Energy | 2004 |
| Hoen Holding AS | Agriculture & fishing | 2005 |
| Hoen Invest AS | Real estate | 2008 |
| Hoensvannsveien SA | Real estate | 1935 |
| Hokksund Auto AS | Other services | 1969 |
| Hokksund Betong AS | Manufacturing | 2013 |
| Hokksund Camping AS | Hospitality | 1997 |
| Hokksund Farmasi AS | Wholesale & retail | 2002 |
| Hokksund Møbelforretning AS | Wholesale & retail | 1974 |
| Hokksund Naprapatklinikk AS | Health & social care | 2015 |
| Hokksund Optiske AS | Wholesale & retail | 2007 |
| Hokksund Service AS | Other services | 2023 |
| Hokksund Sushi Og Thai AS | Hospitality | 2017 |
| Hokksund Utvikling AS | Real estate | 2006 |
| Hokksund Vest Utvikling AS | Real estate | 2013 |
| Hokksundhallen AS | Real estate | 2018 |
| Holding Strong AS | Real estate | 2018 |
| Hole Agentur & Import AS | Wholesale & retail | 1990 |
| Holtefjell AS | Construction | 1982 |
| Holtefjell Eiendomsutvikling AS | Real estate | 2019 |
| Holtefjell Maskin AS | Construction | 2018 |
| Holtefjell Utmarkslag SA | Real estate | 1995 |
| Holth Selskap Og Catering AS | Hospitality | 2024 |
| Hordvik AS | Financial services | 2013 |
| Horgenveien 180 AS | Real estate | 2000 |
| Hoste Holding AS | Construction | 2022 |
| Hougsund Eiendomsselskab AS | Real estate | 1998 |
| Hovland Holding & Invest AS | | 2023 |
| HRK Eiendom AS | Real estate | 2016 |
| HT Industrieiendom AS | Real estate | 2005 |
| HT Kapital AS | | 2026 |
| Hunter-Group AS | Real estate | 2023 |
| Husbutikken Holte & Gulliksen Da | Wholesale & retail | 1993 |
| Håvar Ingebo Holding AS | Construction | 2021 |
| Håvard Lind Holding AS | Real estate | 2005 |
| Hære Overflatebehandling AS | Manufacturing | 2017 |
| Høg Hytta AS | Construction | 2021 |
| Høgås Utvikling AS | Real estate | 2019 |
| Hønengt 59 AS | | 2012 |
| Ic-Solutions AS | Information & communication | 2009 |
| Incident AS | | 2021 |
| Industriveien 18 Eiendom AS | Real estate | 2021 |
| Industriveien 22 AS | Real estate | 2016 |
| Industriveien 28 AS | Real estate | 2006 |
| Ingebo Maskin AS | Construction | 2021 |
| Ingeniør Compagniet Eiendom AS | Real estate | 2000 |
| Ingeniørtjenesten AS | Professional & scientific | 2009 |
| Innholdsspesialisten AS | Professional & scientific | 2024 |
| Intelligent Software AS | Information & communication | 1997 |
| Investoria AS | Real estate | 2005 |
| Iot Medical Ans | Wholesale & retail | 2016 |
| Irby Elektro AS | Construction | 2016 |
| Irby Holding AS | Real estate | 2016 |
| Isell Property AS | Real estate | 2005 |
| Isovator AS | Water & waste | 1995 |
| Itassist AS | Information & communication | 2008 |
| Itassist Consulting AS | Information & communication | 1989 |
| Itouch Nordics AS | Information & communication | 2000 |
| Ivar O Haugen Mat AS | Wholesale & retail | 1997 |
| J&J Bygg Ans | Construction | 2008 |
| Jad Pizza AS | Hospitality | 2023 |
| Jan Erichsen Maskin AS | Construction | 2016 |
| Jawa Invest AS | | 2025 |
| JH Bruun AS | Construction | 2007 |
| Jkrb AS | Real estate | 2020 |
| Johan Aasland AS | Construction | 2021 |
| Johnsen & Enger Bygg AS | Real estate | 2022 |
| Johnsen & Enger Byggservice AS | Construction | 2022 |
| Johnsen & Enger Holding AS | Construction | 2019 |
| Jonasbygg.No AS | Construction | 2021 |
| JW Takst Og Eiendom Avd. Buskerud AS | Professional & scientific | 2011 |
| K Irby Holding AS | Financial services | 2016 |
| K. Bråten AS | Wholesale & retail | 2005 |
| K.R. Larsen Invest AS | Construction | 2005 |
| Kaasa Bygg & Eiendom AS | Real estate | 2023 |
| Kairos Marketing Invest | | 2015 |
| KAMA1 AS | Construction | 2019 |
| Karinas Negler Og Velvære AS | Other services | 2018 |
| Karl Martin Karlsen Drift Og Vedlikehold AS | Wholesale & retail | 2019 |
| Kaspersen Holding AS | | 2019 |
| KB3 Invest AS | Real estate | 2014 |
| Ke Eiendom Og Invest AS | Real estate | 2006 |
| Kenneth Berg Eiendomsdrift AS | Administrative & support | 2026 |
| Kenneth Sjønnegård Holding AS | Transport & logistics | 2024 |
| Kenneth Sjønnegård Transport AS | Transport & logistics | 2024 |
| Khalilo AS | Hospitality | 2020 |
| Kingseeker Da | Arts & recreation | 2022 |
| KJ Irby Holding AS | Construction | 2016 |
| Kjenner Eiendom AS | Real estate | 2006 |
| Klinikk Vigdis AS | Health & social care | 2023 |
| Kliver AS | Professional & scientific | 2005 |
| KM Grunnmur AS | Construction | 2015 |
| Kniveparken AS | Real estate | 2007 |
| Kom Holding AS | Construction | 2021 |
| Kombygg Eiendom AS | Real estate | 2023 |
| Komfri AS | Wholesale & retail | 2014 |
| Komplett Energi AS | Construction | 2017 |
| Kongsberg Eiendom AS | Real estate | 2011 |