| Musqat Trade AS | | 2007 |
| Mykingtoppen AS | Real estate | 2015 |
| NDT Inspection AS | Professional & scientific | 2023 |
| NDT Invest AS | Real estate | 2020 |
| Nisjemetall AS | Wholesale & retail | 2005 |
| Noack AS | Wholesale & retail | 2015 |
| Noralfa AS | Professional & scientific | 2004 |
| Noralfa Holding AS | Wholesale & retail | 2021 |
| Nordic Tours Norge AS | Administrative & support | 2001 |
| Nordisk Gruppen AS | Administrative & support | 2020 |
| Nordisk Yoga Og Meditasjonsskole AS | Education | 2025 |
| Normedica AS | Manufacturing | 1998 |
| Northwise AS | Wholesale & retail | 2026 |
| Oceanshield AS | Information & communication | 2021 |
| Odr AS | | 2026 |
| Olive Group AS | | 2022 |
| Osl Bad AS | Construction | 2026 |
| Partsbygg Ans | Real estate | 1988 |
| Partspark Ans | Real estate | 2006 |
| Peco AS | Health & social care | 1992 |
| Peg Holding AS | Administrative & support | 2022 |
| Peli Eiendom AS | Real estate | 2024 |
| Pengebingen AS | Professional & scientific | 1998 |
| Pike & Peak AS | Administrative & support | 2016 |
| Plain Sight AS | Information & communication | 2025 |
| Planteland A/S | Administrative & support | 1988 |
| Precad AS | Professional & scientific | 2011 |
| Pro Vent AS | Construction | 2026 |
| Protodesign AS | Information & communication | 2018 |
| Prudentia Holding AS | | 2023 |
| Påsche Holding AS | | 2023 |
| Rankor AS | Construction | 2011 |
| Rawsome Invest AS | Manufacturing | 2021 |
| Redivivus AS | Professional & scientific | 2025 |
| Reforcetech AS | Manufacturing | 1990 |
| Regnskap Asker AS | Professional & scientific | 2017 |
| Regnskapsfabrikken AS | Professional & scientific | 2002 |
| Renew Nordic AS | Information & communication | 2024 |
| Ricochet AS | Wholesale & retail | 2026 |
| Rivenholt AS | Information & communication | 2026 |
| RM 214 Holding AS | | 2023 |
| RNP E1 AS | Real estate | 2019 |
| RS Sport AS | Wholesale & retail | 2021 |
| Rud Anlegg AS | Construction | 2023 |
| Rud Holding AS | | 2022 |
| Rulleverden AS | Construction | 2024 |
| Rygg & Rehab AS | Health & social care | 2010 |
| Rønsåsbjørg Invest AS | | 2021 |
| Røyken Barbershop AS | Other services | 2024 |
| Røyken Bil Da | Other services | 1971 |
| Røyken Blikk Og Tømring AS | Construction | 2010 |
| Røyken Eiendom AS | Administrative & support | 2000 |
| Røyken Entreprenør AS | Construction | 2013 |
| Røyken Glass AS | Construction | 2015 |
| Røyken Legekontor AS | Health & social care | 2018 |
| Røyken Og Omegn Dyreklinikk AS | Professional & scientific | 2007 |
| Røyken Rørlegger AS | Construction | 2020 |
| Røyken Transport & Flytting Tjenester AS | Transport & logistics | 2013 |
| Røyken Ved & Slipeservice AS | Agriculture & fishing | 2011 |
| Røykenløkka 1 AS | Real estate | 2022 |
| S.E.P. Consult AS | Professional & scientific | 2012 |
| Sagfoss Eiendom AS | Manufacturing | 2013 |
| Sagfoss Holding AS | Wholesale & retail | 2013 |
| San Marino Røyken AS | Hospitality | 2017 |
| Sandvollen 26 AS | Real estate | 2000 |
| Sangro Invest AS | Real estate | 2011 |
| Sapere Aude AS | | 2020 |
| Selebø Montasje AS | Construction | 2011 |
| Sentrumsgården Røyken AS | Real estate | 2020 |
| SHOES4U AS | Wholesale & retail | 2018 |
| Siham AS | Real estate | 2005 |
| Siv. Ing. Engeset AS | Professional & scientific | 2024 |
| Sjøhagen Invest | Real estate | 2005 |
| Slemmestad Håndverkservice AS | Construction | 2020 |
| Sneve Eiendom AS | Real estate | 2021 |
| Sneve Holding AS | | 2024 |
| Snri Pizza AS | Hospitality | 2019 |
| Solstad Gård Da | Agriculture & fishing | 2024 |
| Sort På Hvitt Ans | Professional & scientific | 1992 |
| Speedwell AS | Transport & logistics | 2012 |
| Spikkestad Bolig AS | Real estate | 2018 |
| Spikkestad Sentrum AS | Real estate | 2023 |
| Spikkestadveien 96 AS | Real estate | 2021 |
| Spikkestadveien 98 AS | Real estate | 2011 |
| Spitting Image AS | Manufacturing | 1994 |
| Sport 1 Røyken AS | Wholesale & retail | 2021 |
| Sportsfly.No AS | Manufacturing | 2018 |
| Spyd Tvilling Holding AS | Construction | 2022 |
| Stag-E AS | Professional & scientific | 2020 |
| Startbra Nuf | Education | 2021 |
| Steffen F Holding AS | | 2022 |
| Storlien Invest AS | | 2020 |
| Støvsugerposer.No AS | Wholesale & retail | 2008 |
| Suit Up AS | Professional & scientific | 2018 |
| Supplay & Aquaculture Professionals AS | Wholesale & retail | 2026 |
| Synsservice AS | | 2018 |
| Sømmelig AS | Wholesale & retail | 2007 |
| T&A Invest AS | | 2005 |
| T.F. Maskin AS | Construction | 2014 |
| T.K. Invest AS | Financial services | 2012 |