| JMS Tracktech AS | Årnes | 2022 |
| JMT Bygg AS | Steinkjer | 2019 |
| JMT Bygg Og Anlegg AS | Leknes | 2016 |
| JMT Gruppen Aps | Kongsberg | 2003 |
| JMT Vedlikehold AS | Snarøya | 2021 |
| Jmødegaard Holding AS | Kristiansand S | 2022 |
| JN Maskin AS | Kvaløya | 2026 |
| JN Rørservice AS | Asker | 2012 |
| JN Tømrerservice AS | Bodø | 2024 |
| JNB Invest AS | Årnes | 2020 |
| JND Hage AS | Sørum | 2026 |
| JNG Montasje AS | Gressvik | 2020 |
| JNH AS | Svelvik | 2022 |
| JNL AS | Verdal | 2023 |
| Jo Asak AS | Leirsund | 2007 |
| Jo Bygg AS | Stryn | 2016 |
| Jo Byggmontasje AS | Finnsnes | 2005 |
| Jo Eiendom AS | Kongsvinger | 2007 |
| Jo Holding AS | Torp | 2023 |
| Jo Industries | Dk-6500 Vojens | 2015 |
| Jo La Byggeservice Ans | Drøbak | 1993 |
| Jo Storsten Service AS | Heimdal | 2012 |
| Jo Våge Bygg AS | Stolmen | 2025 |
| Joakim Engedalen AS | Kongsberg | 2023 |
| Joakim Johansen AS | Sandefjord | 1987 |
| Joar Berg Hjorteland AS | Suldalsosen | 2024 |
| Joar Brekke AS | Hareid | 2011 |
| Joar Bygg AS | Vigrestad | 2021 |
| Joar-S Bygg AS | Kristiansand S | 2023 |
| Job Max Europe | 84-200 Wejherowo | 2007 |
| Jobygg AS | Kristiansand S | 2024 |
| Joda Anlegg AS | Soknedal | 2021 |
| Joda AS | Ski | 2015 |
| Joe Bygg AS | Drammen | 2022 |
| Joe Group AS | Drammen | 2022 |
| Joe S AS | Vuku | 2013 |
| Jofe Holding AS | Steinkjer | 2021 |
| Joflaa Holding AS | Hovin I Gauldal | 2021 |
| Jogioja Building Physics Consult Ltd | 13516 Tallinn | 2016 |
| Jogvan Hammer | Sauda | 1998 |
| Joh AS | Florø | 2008 |
| Johan Aasland AS | Hokksund | 2021 |
| Johan Andresen AS | Trondheim | 1946 |
| Johan Andresen Eiendom AS | Trondheim | 2016 |
| Johan Brekka Entreprenørfirma AS | Kragerø | 1989 |
| Johan Eek-Larsen AS | Bergen | 1977 |
| Johan Gismarvik Maskin AS | Stavanger | 2020 |
| Johan Hansen Glass & Aluminium AS | Aurskog | 1916 |
| Johan Isaksen AS | Lakselv | 1992 |
| Johan Nygren | Kjeller | 2008 |
| Johan Sandstrøm Byggare | Oslo | 2004 |
| Johan Steen AS | Tolga | 2002 |
| Johan Svendsrud El AB | Se-673 91 Charlottenberg | 2012 |
| Johan Westlie & Sønner AS | Ørje | 1990 |
| Johann Langliz | Sandnes | 2008 |
| Johannes Lønvik AS | Ytterøy | 2013 |
| Johannes Madsen Holding AS | Eina | 2024 |
| Johannes Mørkedal Holding AS | Kristiansund N | 2005 |
| Johannes Og Bjørn Inge Eidnes Ans | Lofthus | 1996 |
| Johannesen Byggservice AS | Kjerrgarden | 2016 |
| Johannessen & Paulsen Ans | Gardermoen | 1996 |
| Johannessen AS | Heimdal | 2019 |
| Johannessen Bygg Og Rådgivning AS | Florvåg | 2025 |
| Johannessen Eiendom Invest AS | Løten | 2017 |
| Johannessen Entreprenør AS | Stord | 2016 |
| Johannessen Maskin AS | Slattum | 2025 |
| Johannessen Og Hagen AS | Heimdal | 1996 |
| Johannesson Ventilasjonsmontasje AS | Oslo | 2020 |
| Johansen & Andresen Bygdeservice AS | Auli | 2026 |
| Johansen & Sønn Gulvsliperi AS | Oslo | 2011 |
| Johansen Bad Og Rørservice AS | Oslo | 2006 |
| Johansen Bygg & Eiendom AS | Drøbak | 2019 |
| Johansen Bygg & Rehabilitering AS | Trondheim | 2016 |
| Johansen Bygg Og Takfornying AS | Ridabu | 2024 |
| Johansen Elektriske AS | Bryne | 1989 |
| Johansen Elektro AS | Skien | 2000 |
| Johansen Energi AS | Rolvsøy | 2013 |
| Johansen Gulv & Flis AS | Norheimsund | 2025 |
| Johansen Maskin & Sånn AS | Søgne | 2023 |
| Johansen Maskin & Transport AS | Nord-Lenangen | 2005 |
| Johansen Maskin AS | Tennevoll | 1990 |
| Johansen Maskin AS | Korgen | 2003 |
| Johansen Maskin Og Arbeidsutleie AS | Sørstraumen | 2021 |
| Johansen Maskin Og Eiendom AS | Bud | 2017 |
| Johansen Og Nicolaisen Ans | Mo I Rana | 1996 |
| Johansen Prosjektmontasje AS | Skiptvet | 2003 |
| Johansen Rør AS | Skånevik | 2021 |
| Johansen Rørleggerservice AS | Leknes | 2011 |
| Johansen Rørservice AS | Sømna | 2017 |
| Johansen VVS AS | Oslo | 1997 |
| Johansen-Maskin AS | Sokna | 2022 |
| Johansen-Vvs AS | Sandnes | 2010 |
| Johansson Bygg & Design AS | Bjørndalstræ | 2025 |
| Johansson Bygg AS | Fana | 2025 |
| Johanssons Entreprenad Norge AB | Se-66593 Kil | 2019 |
| John a Larsen AS | Ålesund | 1991 |
| John Aage Knuten Holding AS | Vegårshei | 2021 |
| John Amundsen.Bygg AS | Trondheim | 2019 |
| John Arve Halhjem AS | Os | 2010 |
| John Bitis Maskinstasjon AS | Kautokeino | 2006 |