| Hehena AS | | 2018 |
| Helikopter Utleige AS | Transport & logistics | 2001 |
| Helle Næringstomt AS | Real estate | 2022 |
| Hellesund AS | Real estate | 2008 |
| Hellesund Eiendom AS | Real estate | 1970 |
| Hellesund Utvikling AS | Real estate | 2017 |
| Helm Skandinavien Nuf | Wholesale & retail | 2012 |
| Hemo Bygg AS | Construction | 2024 |
| Hemo Eiendom AS | | 2016 |
| Hemo Heldal AS | Transport & logistics | 2018 |
| Hera TM AS | | 2026 |
| Heuchgården Eiendom AS | Real estate | 2015 |
| HGB Jakt AS | Arts & recreation | 2024 |
| Hildursdotter Holding AS | | 2026 |
| Hjallum AS | Construction | 1978 |
| Holmvann AS | | 2025 |
| Hos Gro AS | Hospitality | 2017 |
| Howatson Invest AS | | 2019 |
| Humlehaven AS | Information & communication | 2015 |
| Hydrovegen Eiendom AS | Real estate | 2010 |
| Hydrowatt AS | Professional & scientific | 2018 |
| Håndverksekspressen Ans | | 1990 |
| Hårstua AS | Other services | 1993 |
| Hølzermann AS | Real estate | 2012 |
| Iboa Holding AS | | 2022 |
| Indidye Europe AS | Wholesale & retail | 2018 |
| Indidye Holding AS | Wholesale & retail | 2020 |
| Industrino AS | Information & communication | 2004 |
| Ingro - Holding AS | Financial services | 2005 |
| Inthex AS | Professional & scientific | 2026 |
| Isaksen Byggservice AS | Construction | 2022 |
| Isg AS | Transport & logistics | 1992 |
| Iwbb AS | Wholesale & retail | 2020 |
| J.A Holding AS | | 2026 |
| Jaheka Holding AS | Wholesale & retail | 2005 |
| Janke AS | | 2021 |
| Jannecke Stabell AS | Professional & scientific | 2020 |
| Jens a Schou Mek Verksted AS | Real estate | 1962 |
| JMT Holding Kragerø AS | | 2019 |
| JMT Import AS | Professional & scientific | 2017 |
| Jobb Profilering AS | Professional & scientific | 2018 |
| Johan Brekka Entreprenørfirma AS | Construction | 1989 |
| John Erik Dukefoss & Kim Morgan Brekka Da | Education | 2013 |
| Johnny Jensen AS | Construction | 1986 |
| Johnny Jensen Holding AS | Real estate | 1986 |
| Jomfruland Nasjonalparksenter AS | Arts & recreation | 2023 |
| Jonmaj Holding AS | Real estate | 2011 |
| Jos Shipping AS | Transport & logistics | 1996 |
| Joto Bygg&Tømrermester AS | Construction | 2023 |
| Jppj Holding AS | Real estate | 2020 |
| Jås Eiendom AS | Real estate | 2018 |
| Jøfys AS | Agriculture & fishing | 2024 |
| Jørgen Holding AS | Real estate | 2021 |
| Jørgen Jørgensen Eiendom AS | Real estate | 2008 |
| K-Foss Eiendom AS | Real estate | 1981 |
| K-Foss Vedlikehold AS | Construction | 2012 |
| K. Rønning Eiendom AS | Real estate | 2020 |
| Kalstad Auto Senter AS | Wholesale & retail | 2009 |
| Kalstad Eiendom AS | Real estate | 1997 |
| Kalstad Utvikling AS | Real estate | 1997 |
| Kalstadveien 1 AS | Real estate | 2022 |
| Kan-Eiendom AS | Real estate | 2020 |
| Karl Kapital Holding AS | | 2024 |
| Kastleblack AS | Professional & scientific | 2020 |
| Kbbl Utbygging AS | Real estate | 2005 |
| Kbce Eiendom AS | Real estate | 2011 |
| Kbf-Holding AS | | 2026 |
| KBS Kragerø Holding AS | Construction | 2013 |
| Kby Holding AS | Hospitality | 2023 |
| KDK Holding AS | Financial services | 2017 |
| Kikut Utbygging AS | Real estate | 2022 |
| Kilden Da | Health & social care | 1999 |
| Kilen Eiendom AS | Real estate | 1992 |
| Kioskdrift Hilde Elise Mogen AS | Wholesale & retail | 2026 |
| Kirkebukta AS | Real estate | 2014 |
| Kirkebukta Dagligvare AS | Wholesale & retail | 2015 |
| Kirkebukta Drivstoff AS | Wholesale & retail | 2016 |
| Kirkegata 2A AS | Real estate | 2022 |
| Kirkegt 13 AS | Real estate | 1993 |
| Kivle Eiendom AS | Real estate | 1986 |
| Kivle Invest AS | Real estate | 2012 |
| Kjendal AS | Real estate | 2005 |
| Kjendal Eiendom AS | Real estate | 1994 |
| Klausen Båt AS | Wholesale & retail | 2018 |
| Kleven Invest Drift AS | Professional & scientific | 2021 |
| Kleven Invest Holding AS | Real estate | 2021 |
| Kompetansebygg Tangen AS | Real estate | 1999 |
| Kontrabass Holding AS | Real estate | 2012 |
| Kontre Kommunikasjon AS | Professional & scientific | 2020 |
| Kragerø Asia Matt AS | Wholesale & retail | 2023 |
| Kragerø Auto AS | Wholesale & retail | 2016 |
| Kragerø Blad AS | Information & communication | 1997 |
| Kragerø Bredbånd AS | Information & communication | 2005 |
| Kragerø Bruktsalg Og Utleie AS | Wholesale & retail | 2023 |
| Kragerø BS Eiendom AS | Real estate | 2021 |
| Kragerø Bygg Og Sjøfrakt AS | Construction | 2013 |
| Kragerø Båt Og Reparasjon AS | Manufacturing | 2021 |
| Kragerø Eiendom AS | Real estate | 1981 |
| Kragerø Elektriske AS | Construction | 1993 |
| Kragerø Energi AS | Energy | 2011 |