| GN Rør AS | Construction | 2022 |
| Gode Råd Bygg AS | Professional & scientific | 2013 |
| Golftunet AS | Professional & scientific | 2016 |
| Grand Erp AS | Information & communication | 2015 |
| Grande AS | Construction | 2007 |
| Green AS | Arts & recreation | 2018 |
| Gregersen Eiendommer AS | Real estate | 1986 |
| Grindløkken AS | Real estate | 2017 |
| Grocery Lab Store AS | Wholesale & retail | 2021 |
| Grytnes Holding AS | | 2005 |
| Grønn Chilli AS | Hospitality | 2020 |
| Grøtterud Invest AS | Hospitality | 2013 |
| Gullkronen AS | Financial services | 2016 |
| Gullsmed Finn Andersen AS | Wholesale & retail | 1979 |
| Gummiteknikk AS | Wholesale & retail | 2009 |
| Gustav AS | | 2017 |
| GW Utleie AS | Manufacturing | 2023 |
| H. Hjetland AS | Education | 2005 |
| H.A.S. Auto AS | Wholesale & retail | 1997 |
| H.T.G. Eiendom AS | Real estate | 2009 |
| Ha Takst AS | Real estate | 2023 |
| Hai Jing Restaurant AS | Hospitality | 2025 |
| Haijing Holding AS | Real estate | 2023 |
| Hallings Gate Horten AS | Real estate | 2006 |
| Halvstorm AS | Real estate | 2018 |
| Hanjan Invest AS | Financial services | 2005 |
| Hansebakken Transport AS | Real estate | 2018 |
| Happening Invest AS | | 2023 |
| Harelabb Production AS | Information & communication | 2016 |
| Harpix Heartwood Empire AS | Arts & recreation | 2012 |
| Has Byggservice | Construction | 1997 |
| Haviland AS | | 2026 |
| Havneparken AS | Real estate | 2016 |
| HB. Holding AS | Real estate | 2019 |
| HBP Invest AS | Construction | 2005 |
| HBP Prosjekt AS | Construction | 2018 |
| Hbpn AS | | 2023 |
| HCB Invest AS | Financial services | 2008 |
| HCH AS | Hospitality | 2013 |
| HD Customs Invest Limited Nuf | | 2024 |
| Heb AS | Administrative & support | 2009 |
| Heb Entreprenør AS | Construction | 2014 |
| Heimstad Holding AS | Wholesale & retail | 2014 |
| Hekseakademiet AS | Professional & scientific | 2021 |
| Helgesen Software AS | Information & communication | 2023 |
| Hellerud Consulting AS | | 2025 |
| Heltivater Invest AS | Construction | 2022 |
| Henning Shapes AS | Manufacturing | 2020 |
| Herr & Fru Hamre Holding AS | Professional & scientific | 2023 |
| Herwell Blikk Og Håndtverk AS | Construction | 2025 |
| Hessen Bygg & Utvikling AS | Construction | 2021 |
| Hestegalleriet AS | Information & communication | 2024 |
| Hetterviks Eiendom AS | Real estate | 2025 |
| Hgo Tech AS | Real estate | 2005 |
| Hi Fay AS | Information & communication | 2025 |
| Himalaya AS | Real estate | 2014 |
| Hip Bekkajordet 3 AS | Real estate | 2006 |
| Hip Bygg 60 AS | Real estate | 2023 |
| Hip Bygg 65 AS | Real estate | 2023 |
| Hip Forvaltning AS | Energy | 2013 |
| Hip Langgrunn AS | Real estate | 2023 |
| Hjertets Vei AS | Education | 2024 |
| Hoa Beauty Lashes AS | Wholesale & retail | 2017 |
| Hobbydilla AS | Wholesale & retail | 2018 |
| Hof Holdning AS | | 2026 |
| Holes Delikatesse Og Catering AS | Hospitality | 2023 |
| Holsøe Holding AS | | 2016 |
| Holt Capital AS | | 2025 |
| Holtanløkka AS | Real estate | 2004 |
| Holth Egeberg AS | | 2017 |
| HORT1 Invest AS | | 2024 |
| Horten Begravelsesbyrå AS | Other services | 2018 |
| Horten Bil Og Båt Elektro AS | Other services | 2014 |
| Horten Bilpleie Og Dekk AS | Other services | 2021 |
| Horten Blikk Og Sveis AS | Construction | 2016 |
| Horten Blomster - Hortensia AS | Wholesale & retail | 2012 |
| Horten Boligservice AS | Construction | 2026 |
| Horten Bowling AS | Arts & recreation | 2026 |
| Horten Bryggeri AS | Manufacturing | 1992 |
| Horten Budservice Da | Transport & logistics | 1999 |
| Horten Bygg Og Elektro Kompetanse AS | | 2019 |
| Horten Bygg Service AS | Construction | 2018 |
| Horten Båt Og Maskinutleie AS | Administrative & support | 2023 |
| Horten Båtsenter AS | Wholesale & retail | 2007 |
| Horten Båtsenter Holding AS | Wholesale & retail | 2022 |
| Horten Børs AS | Hospitality | 2024 |
| Horten Dekksenter AS | Wholesale & retail | 2014 |
| Horten Dyreklinikk Vestfold AS | Professional & scientific | 2012 |
| Horten Eiendom AS | Real estate | 2016 |
| Horten Eiendomsselskap Ans | Real estate | 2010 |
| Horten Eiendomsutleie Ans | Real estate | 2008 |
| Horten Elektro Service AS | Construction | 2018 |
| Horten Food AS | Hospitality | 2022 |
| Horten Fysioterapi Og Manuellterapi AS | Health & social care | 2018 |
| Horten Gjennbruk AS | Real estate | 2024 |
| Horten Hotelldrift AS | Hospitality | 1997 |
| Horten Hudpleieklinikk AS | Other services | 2013 |
| Horten Industripark AS | Real estate | 1990 |
| Horten Invest AS | Professional & scientific | 2010 |
| Horten Kontor & Regnskap Da | Professional & scientific | 1987 |