| Roland Holding AS | | 2005 |
| Rolf Sletvold Interiørsenter AS | Wholesale & retail | 1981 |
| Romerike Autosalg AS | Wholesale & retail | 2017 |
| Romerike Bad AS | Construction | 2012 |
| Romerike Balkongmontasje AS | Construction | 2004 |
| Romerike Betonggulv AS | Construction | 2024 |
| Romerike Bilvask AS | Other services | 2021 |
| Romerike Boligdesign AS | Professional & scientific | 2017 |
| Romerike Byggteknikk AS | Construction | 2025 |
| Romerike Drift AS | Administrative & support | 2012 |
| Romerike Entreprenør AS | Construction | 2024 |
| Romerike Foto AS | Wholesale & retail | 2008 |
| Romerike Kompetansehus AS | Real estate | 2012 |
| Romerike Maler & Bygg AS | Construction | 2024 |
| Romerike Sentrum AS | Real estate | 1992 |
| Romeriksbunad AS | Manufacturing | 2017 |
| Romsaas Holding AS | Real estate | 2005 |
| Rosen Consult AS | Education | 2022 |
| Rosenborggata 1 AS | Real estate | 2026 |
| Roy Nordal AS | Financial services | 2013 |
| RS Blikk Og Miljømontasje Da | Construction | 2004 |
| RS Eiendom Sør 2 AS | Real estate | 2016 |
| RS Eiendom Sør AS | Real estate | 2011 |
| RS Global Trading AS | Wholesale & retail | 2024 |
| RST Elektro AS | Construction | 2012 |
| Rudi Autosalg AS | Wholesale & retail | 2025 |
| Rufi AS | Real estate | 2008 |
| Rundtom Holding AS | | 2018 |
| Rustadgården Bygg Og Eiendom AS | Real estate | 2016 |
| Rustadgården Holding AS | Real estate | 2015 |
| Rutim AS | Real estate | 2015 |
| Ruud Boligutleie AS | Real estate | 2024 |
| Ruud Eiendom Holding AS | Real estate | 2024 |
| Råholt Tomteutvikling AS | Real estate | 2019 |
| Råholtgutua AS | Real estate | 2014 |
| Rø & Frø Invest AS | | 2020 |
| Røn-Rek AS | Wholesale & retail | 1987 |
| S North AS | Construction | 2026 |
| S.A.B.-Bygg AS | Construction | 2003 |
| Sa-Ce-Mi AS | Professional & scientific | 2006 |
| Saareko Grupp Oü | Construction | 2010 |
| Sabrura Jessheim AS | Hospitality | 2026 |
| Safedeck AS | Wholesale & retail | 2024 |
| Sag Eiendom AS | Real estate | 2007 |
| Saga Musikkforlag AS | Professional & scientific | 2024 |
| Sagabyen Omsorg AS | Real estate | 2016 |
| Saggata 7 AS | Real estate | 2022 |
| Sailing Monkeys AS | Hospitality | 2024 |
| Sake Sushi Da | Hospitality | 2011 |
| Sakina Konsult AS | Professional & scientific | 2017 |
| Saks Og Nål AS | Manufacturing | 2023 |
| Salgstinget AS | Education | 2009 |
| Salong Duett AS | Other services | 2012 |
| Salong Kaktus AS | Other services | 2024 |
| San Transport AS | Transport & logistics | 2017 |
| Sandaker Holding AS | Professional & scientific | 2017 |
| Sandbakken Bygg AS | Construction | 2022 |
| Sandmo Eiendomsdrift AS | Real estate | 2013 |
| Sandtaket AS | | 2020 |
| Sankan Invest AS | Financial services | 2015 |
| Sanum AS | Health & social care | 2024 |
| Sapp Holding AS | Other services | 2021 |
| Sara Kolonial AS | Wholesale & retail | 2021 |
| Sarpsborg Handel AS | Wholesale & retail | 2026 |
| Satay Catering AS | Hospitality | 2014 |
| Sayl AS | | 2020 |
| SB Serviceutleie AS | Administrative & support | 2021 |
| SBL Holding AS | | 2023 |
| Scandicar AS | Wholesale & retail | 2023 |
| Scandinavia RC Import Ans | Wholesale & retail | 2000 |
| Scanpax AS | Professional & scientific | 2013 |
| Scapin AS | Administrative & support | 2018 |
| Schjervheim Invest AS | | 2024 |
| Schjoll Invest AS | Construction | 2022 |
| Seadesigntretek AS | Construction | 2025 |
| Sean Adrian's Dagligvare AS | Wholesale & retail | 2004 |
| Select Auto AS | Wholesale & retail | 2022 |
| Select Property AS | Real estate | 2025 |
| Sendstad Holding AS | | 2009 |
| Seno Bygg AS | Construction | 2021 |
| Sentrumsbygg Eiendomsselskap AS | Real estate | 1987 |
| Seven Flash AS | Transport & logistics | 2024 |
| Seven Seconds AS | | 2014 |
| SG Cargo AS | Transport & logistics | 2026 |
| Shankly Invest AS | Real estate | 2021 |
| SHG Rental AB Nuf | Wholesale & retail | 2025 |
| Shimary Holding AS | Wholesale & retail | 2024 |
| Sifo Invest AS | Real estate | 2008 |
| Sigma Gruppen AS | Real estate | 2003 |
| Sigma Utvikling AS | Real estate | 2002 |
| Sign Consult Norway AS | Professional & scientific | 1993 |
| Sigurd Furulund Eiendom AS | Real estate | 2003 |
| Sigurd Furulund Holding AS | Construction | 2005 |
| Sigurd Furulund Maskin AS | Construction | 1996 |
| Sigurdur Guttormsson Transport AS | Administrative & support | 2017 |
| Sjholding AS | | 2026 |
| Sjøveian AS | Transport & logistics | 2026 |
| SK Lege AS | Health & social care | 2023 |
| Skalor AS | Information & communication | 2026 |
| Skarestrand Aktiv AS | Professional & scientific | 2016 |