| Romerike Consult & Mesterbedrift AS | Skarnes | 2012 |
| Romerike Elektro AS | Kløfta | 1996 |
| Romerike Elservice AS | Oslo | 2025 |
| Romerike Energi AS | Sørum | 1977 |
| Romerike Entreprenør AS | Jessheim | 2024 |
| Romerike Fuging AS | Algarheim | 2022 |
| Romerike Holding AS | Fetsund | 2022 |
| Romerike Klimaservice AS | Eidsvoll Verk | 2010 |
| Romerike Maler & Bygg AS | Jessheim | 2024 |
| Romerike Malermesterforretning AS | Kløfta | 2018 |
| Romerike Malerservice Ans | Rånåsfoss | 2007 |
| Romerike Maskin AS | Årnes | 2003 |
| Romerike Maskinlag AS | Skogbygda | 2019 |
| Romerike Oppussing AS | Rakkestad | 2017 |
| Romerike Pipe Service AS | Maura | 2018 |
| Romerike Portservice AS | Skedsmokorset | 2026 |
| Romerike Profilteknikk AS | Lillestrøm | 1994 |
| Romerike Rørleggerbedrift AS | Kløfta | 2006 |
| Romerike Rørteknikk AS | Rælingen | 2017 |
| Romerike Tak Og Blikk AS | Nittedal | 2011 |
| Romerike Tak Og Fasade AS | Gjerdrum | 2024 |
| Romerike Tak Og Membran AS | Gjerdrum | 2023 |
| Romerike Ventilasjon AS | Hvam | 2022 |
| Romerike VVS AS | Fjerdingby | 2023 |
| Romløft AS | Oslo | 2026 |
| Rommex Oü Nuf | Ee-46703 Väike-Andrese | 2026 |
| Roms Bygg AS | Tverrelvdalen | 2025 |
| Romsdal Elektro AS | Molde | 2004 |
| Romsdal Maskin AS | Molde | 2007 |
| Romsdal Montasje & Service AS | Eidsbygda | 2016 |
| Romsdal Service AS | Molde | 2018 |
| Romsdal Teleservice AS | Åndalsnes | 2023 |
| Romsdalssol AS | Åndalsnes | 2023 |
| Romsly AS | Aurskog | 2023 |
| Romstad Klimateknikk AS | Moss | 2025 |
| Ronalds Rør & Sveiceservice AS | Larvik | 2012 |
| Rondane Entreprenør AS | Sør-Fron | 2005 |
| Rondane Fjellteknikk AS | Otta | 2026 |
| Rongesund Drift AS | Rong | 2023 |
| Rongve Og Fylling Elektro AS | Ellingsøy | 2009 |
| Roni Invest AS | Oslo | 2006 |
| Ronni Røang Holding AS | Hedalen | 2021 |
| Ronningen Holding AS | Nærbø | 2021 |
| Ronny Haugen AS | Åmot | 2021 |
| Ronny Haugen Fyringsservice AS | Nes Verk | 2020 |
| Ronny Hermansen AS | Alta | 2022 |
| Ronny Husevåg Rørservice AS | Sandane | 2004 |
| Ronny Ledings Snekkerfirma AS | Tromsø | 2015 |
| Ronny Robertsen AS | Tromsdalen | 2012 |
| Ronny Tennfjord AS | Skodje | 2021 |
| Ronny's Bygg AS | Steinsdalen | 2017 |
| Ronny's Maskin AS | Dagali | 2013 |
| Ronnys Anleggsservice AS | Oslo | 2006 |
| Roof-Tec Krystian Wichrowski | Pl - 32 215 Krakow | 2025 |
| Roofing | Se-981 35 Kiruna | 2017 |
| Roofmaster | Lv-1011 Riga | 2017 |
| Rooftop AS | Oslo | 2018 |
| Rope Access Sverige AB | Se-171 63 Solna | 2011 |
| Ropes & Blades S.R.L. Nuf | Ro-05244 Bucuresti | 2026 |
| Ropro AS | Røyneberg | 2022 |
| Rorge Restaurering AS | Engeløya | 2017 |
| ROS1DAL Holding AS | Trondheim | 2018 |
| Rosa Blikk AS | Grimstad | 2022 |
| Rosa Gruppen AS | Fevik | 2022 |
| Rosbach & Forsland Bygg AS | Skien | 2023 |
| Rosco Pim SP. Z O.O. Nuf | 35-211 Rzeszow | 2023 |
| Rosells Kakel & Bygg AB | Se-783 90 Säter | 2011 |
| Rosen Bygg Og Flis AS | Våler I Solør | 2025 |
| Rosenbakk AS | Trondheim | 2014 |
| Rosenbergservice AS | Lørenskog | 2021 |
| Rosenborg Bolig AS | Oslo | 2021 |
| Rosenborg Eiendomsservice AS | Larvik | 2026 |
| Rosenborg Malerteam AS | Trondheim | 1994 |
| Rosenborg Murhåndtverk AS | Trondheim | 2020 |
| Rosendal Bygg & Varme AS | Seimsfoss | 2009 |
| Rosendal Bygg AS | Trondheim | 2021 |
| Rosendal Malerservice AS | Trondheim | 2023 |
| Roseneng Maskin AS | Lakselv | 2017 |
| Rosengren Bygg AS | Stavanger | 2010 |
| Rosengården Bygg & Innredning AS | Fetsund | 2005 |
| Rosenholm Anlegg AS | Oslo | 2015 |
| Rosenkrantzgaarden AS | Sola | 2010 |
| Rosenmeyer AS | Skjomen | 2019 |
| Rosenvold Drift AS | Grimstad | 2026 |
| Roser Bolig AS | Tønsberg | 2018 |
| Roseth Bygg AS | Straume | 1987 |
| Rosia Eiendomservice AS | Sandefjord | 2014 |
| Rosing's Holding AS | Hagan | 2005 |
| Rosings Industrier AS | Hagan | 1987 |
| Rosko AS | Oslo | 2017 |
| Rosland Invest AS | Orre | 2005 |
| Rosnes AS | Lindås | 2025 |
| Rosnes Maskin AS | Randaberg | 2024 |
| Rosonerri Job Oü Nuf | Ee-10416 Tallinn | 2021 |
| Ross Snekkertjenester AS | Melhus | 2004 |
| Rosseland Maskin AS | Mosby | 2015 |
| Rossing Rørleggerbedrift AS | Oslo | 2013 |
| Rostad Byggservice AS | Klavestadhaugen | 2008 |
| Rosten Maskin AS | Sel | 2012 |
| Rosvet Nord AS | Trysil | 2013 |