| Platinum AS | Transport & logistics | 2022 |
| Plus IT AS | Information & communication | 2017 |
| Polartekst AS | Professional & scientific | 2019 |
| Pompelogpilt Barneklær Ans | Wholesale & retail | 2002 |
| Prconsultant Holm AS | Professional & scientific | 2026 |
| Primadent AS | Health & social care | 2020 |
| Primetransport AS | Transport & logistics | 2024 |
| Protag AS | Information & communication | 2025 |
| PS Invest AS | Real estate | 2004 |
| PTS Skiba AS | Construction | 2022 |
| Qualis Eiendom AS | Professional & scientific | 2005 |
| R. Våge AS | Construction | 2013 |
| Radonhjelpen Øst AS | Professional & scientific | 2023 |
| Rasen AS | Real estate | 1993 |
| Rauf Group AS | | 2026 |
| Recovia AS | Education | 2026 |
| Regnskapstjenester Lillestrøm AS | Professional & scientific | 2012 |
| Reime Gjødselsystemer AS | Manufacturing | 2021 |
| Remi Bygg Ans | Construction | 2006 |
| Ringen Apotek Rælingen AS | Wholesale & retail | 2013 |
| Romerike Bad & Snekkerservice AS | Construction | 2025 |
| Romerike Truckservice AS | Manufacturing | 1989 |
| Romerike VVS AS | Construction | 2023 |
| Ronny Og Heidi AS | Education | 2012 |
| RS Oppmerking AS | Construction | 2024 |
| RSH Holding AS | | 2018 |
| Rut Eiendom AS | Real estate | 2017 |
| Rut Eiendom Tomteselskap AS | Real estate | 2018 |
| Rånås Living AS | Real estate | 2023 |
| Rælingen Legesenter AS | Health & social care | 2024 |
| Rælingen Pizza AS | Hospitality | 2022 |
| Rør & Sprinkler Companiet AS | Construction | 2003 |
| Rør Og Eiendom AS | Construction | 2023 |
| Samsan AS | Construction | 2024 |
| Sans Aurora AS | Wholesale & retail | 1979 |
| Sanste Holdings AS | | 2025 |
| SC Facility Services AS | Administrative & support | 2026 |
| Scandic Eiendom AS | Real estate | 2023 |
| Schreiner Holding AS | Construction | 2016 |
| Scientific Perspectives AS | Professional & scientific | 2013 |
| SDK Consult AS | Professional & scientific | 2026 |
| SDK Holding AS | Professional & scientific | 2015 |
| SDL AS | Transport & logistics | 2020 |
| Seniorsens AS | Wholesale & retail | 2013 |
| Serko Invest AS | Real estate | 2012 |
| Setertek AS | Information & communication | 2026 |
| Shahdost Enterprise Da | Wholesale & retail | 2014 |
| Shawarma Houses AS | Hospitality | 2024 |
| Shutterworks AS | Professional & scientific | 2024 |
| Sildpollnes Invest AS | Real estate | 2025 |
| Sip Holding AS | Real estate | 2023 |
| Sisac AS | Professional & scientific | 2021 |
| Skamsar Invest AS | | 2025 |
| Skandia Holding AS | Wholesale & retail | 2022 |
| Skandia Møbler AS | Wholesale & retail | 2022 |
| Skovholt Ans | Agriculture & fishing | 1973 |
| Smack AS | Wholesale & retail | 2004 |
| Smedheim AS | Wholesale & retail | 2023 |
| Smestad Utvikling AS | Real estate | 2008 |
| SML Systems AS | Wholesale & retail | 2026 |
| Sne Holding AS | | 2021 |
| Sogra Holding AS | | 2026 |
| Solar Power AS | Professional & scientific | 2026 |
| Solli Eiendom AS | Real estate | 1995 |
| Sollytunet Eiendom AS | Real estate | 2023 |
| Solnera AS | Wholesale & retail | 2025 |
| Solskjerming Service AS | Wholesale & retail | 2014 |
| Sone 4 AS | Information & communication | 2024 |
| Sparta Holding Inc AS | | 2024 |
| Sparta Invest AS | Wholesale & retail | 2017 |
| Sply AS | Information & communication | 2018 |
| Spyleservice AS | Water & waste | 2014 |
| Squeakyclean AS | Administrative & support | 2024 |
| SRS Riis AS | Hospitality | 2022 |
| Stanbe AS | | 2023 |
| Stemt AS | Information & communication | 2017 |
| Stig Nordby Holding AS | Financial services | 2018 |
| Stima AS | Real estate | 2005 |
| Stima Bygg AS | Administrative & support | 2007 |
| Stima Drift AS | Professional & scientific | 2022 |
| Stima Studio AS | Real estate | 2023 |
| Stimaco 1 AS | Real estate | 2022 |
| STN Eiendom AS | Real estate | 2025 |
| Storbakken Håndverkservice AS | Construction | 2016 |
| Støperiveien 26 Eiendom AS | Real estate | 2008 |
| Succinum AS | Information & communication | 2026 |
| Sundhagen Invest AS | | 2021 |
| Sveen Og Emberland Illustrasjon AS | Manufacturing | 2006 |
| Sveum Invest AS | | 2006 |
| Sveva AS | | 2026 |
| SW Bolig AS | Construction | 2023 |
| SW Eiendom AS | | 2020 |
| Synheim AS | | 2026 |
| Synkd.Ai AS | Information & communication | 2025 |
| Sørlie-Larsen AS | | 2019 |
| T&K Granlund Holding AS | Construction | 2023 |
| Takst Øst AS | Real estate | 2013 |
| Tangen Barnehage SA | Education | 1989 |
| Tangen Grendelag SA | Information & communication | 1988 |
| Taraldset Nomerstad Holding AS | | 2025 |