| Hverdagsgull AS | Wholesale & retail | 2024 |
| Hvite Vinger Invest AS | | 2025 |
| Hvitsand Invest AS | | 2024 |
| Hvoslef AS | Wholesale & retail | 2016 |
| HW Eiendomsdrift AS | Real estate | 2021 |
| HW Hornet AS | | 2020 |
| HWK Holding AS | | 2026 |
| Hybond AS | Manufacturing | 2007 |
| Hydrogen Mem-Tech AS | Manufacturing | 2016 |
| Hydronext AS | Professional & scientific | 2024 |
| Hydrospective AS | Professional & scientific | 2024 |
| Hyl Production Ans | Professional & scientific | 2017 |
| Hyldra Technologies AS | Information & communication | 2021 |
| Hyllavegen Røra AS | Real estate | 2012 |
| Hymatech AS | Manufacturing | 2019 |
| Hypermass AS | Information & communication | 2022 |
| Hypermata AS | Information & communication | 2018 |
| Hyperspeed Studio AS | Information & communication | 2026 |
| Hytteinvest Nord AS | Real estate | 2021 |
| Hytteverden AS | Real estate | 2020 |
| Håbet AS | | 2026 |
| Håbrubekken AS | Real estate | 2019 |
| Håkon Jarl Eiendom AS | Real estate | 2017 |
| Håkon Magnussons Gate AS | Wholesale & retail | 2015 |
| Håkon Sporstøl Holding AS | | 2025 |
| Hålu AS | Information & communication | 2020 |
| Håndbak Holding AS | | 2022 |
| Håndverkerforsikring AS | Financial services | 2016 |
| Håndverkern Din AS | Construction | 2007 |
| Håp Om Utbytte AS | | 2026 |
| Hår-Frisør AS | Other services | 2000 |
| Hårik AS | Real estate | 2006 |
| Hårik Drift AS | Real estate | 2022 |
| Hårik Eiendom AS | Real estate | 2018 |
| Hårstad Hestesenter AS | Arts & recreation | 1994 |
| Håvard Østerås AS | Health & social care | 2008 |
| Hærlig AS | Financial services | 2016 |
| Hærverk Forlag AS | Information & communication | 2022 |
| Høg Areal AS | | 2026 |
| Høg Bolig AS | Real estate | 2025 |
| Høg Drift AS | Administrative & support | 2012 |
| Høg Eiendom AS | Real estate | 2022 |
| Høg Holding AS | Real estate | 2019 |
| Høgmovegen Eiendom AS | Real estate | 2023 |
| Høieggen Holding AS | Real estate | 2008 |
| Høitrans AS | Transport & logistics | 2022 |
| Høknes Holding AS | | 2023 |
| Hørløcks Veg 68 AS | Real estate | 2023 |
| Høvleriet Stjern AS | Manufacturing | 2026 |
| Høydal Prosjektering AS | Professional & scientific | 1988 |
| Høyel Holding AS | | 2026 |
| Høyer Solsiden AS | Wholesale & retail | 2007 |
| Høyer Trondheim AS | Wholesale & retail | 2013 |
| Høyt Og Lavt Trondheim AS | Arts & recreation | 2016 |
| Høytrykksteknikk Midt-Norge AS | Manufacturing | 2023 |
| I Godt Selskap Da | Information & communication | 2006 |
| I Grande Frisør AS | Other services | 1995 |
| I K Lykke AS | Wholesale & retail | 1918 |
| I K Lykke Drift AS | Wholesale & retail | 2014 |
| I K Lykke Eiendom AS | Real estate | 2018 |
| I K Lykke Eiendom Bolig AS | Real estate | 2021 |
| I K Lykke Eiendom Holding AS | Real estate | 2018 |
| I Ro Bolig AS | Professional & scientific | 2025 |
| I Wibe AS | Real estate | 2016 |
| I-Valberg Holding AS | | 2021 |
| I. Aa Holding AS | | 2023 |
| I. K. Huitfeldt & Co AS | | 2020 |
| Iah Holding AS | | 2025 |
| Ibadge AS | Information & communication | 2026 |
| Ibbi-Records AS | Arts & recreation | 2017 |
| Ibbo AS | | 2025 |
| Ibe Holding AS | Health & social care | 2015 |
| Ibex Invest AS | Real estate | 2021 |
| Ibms Holding AS | Professional & scientific | 2017 |
| Iboli AS | Real estate | 2021 |
| Ibooking AS | Information & communication | 2011 |
| Ibs AS | | 2025 |
| Ibsen Ans | Real estate | 2001 |
| Ibss AS | Other services | 2015 |
| Ic Technology AS | Professional & scientific | 2009 |
| Ice Holdings AS | | 2024 |
| Ice Media AS | Arts & recreation | 2013 |
| Icon Nettdrift Da | Information & communication | 1996 |
| Iconomy AS | Professional & scientific | 2017 |
| Ictum AS | | 2024 |
| Id Frisør AS | Other services | 2018 |
| Ida Hassel AS | Professional & scientific | 2021 |
| Idab Holding AS | | 2021 |
| Idak AS | | 2023 |
| Idavollen Invest AS | Professional & scientific | 2005 |
| Iddos AS | Real estate | 2017 |
| Ide Rik AS | Professional & scientific | 2014 |
| Idehus Trondheim Prosjekter AS | Real estate | 2008 |
| Idehusgruppen AS | Construction | 1999 |
| Idletechs AS | Professional & scientific | 2014 |
| Idn Invest AS | Professional & scientific | 2011 |
| Idn Research AS | Professional & scientific | 2013 |
| Idrettsbingo AS | Arts & recreation | 1986 |
| Idrettsdata Da | Information & communication | 1993 |
| Idungården Fotklinikk AS | Health & social care | 2013 |