| Seinvest AS | Real estate | 2017 |
| Sekla AS | Real estate | 2005 |
| Selecta AS | Professional & scientific | 1993 |
| Selecta Bygg AS | Construction | 2017 |
| Seljestad AS | Information & communication | 2006 |
| Sella Invest AS | Real estate | 1999 |
| Selskap 2026 | Manufacturing | 2020 |
| Senior Drift AS | Professional & scientific | 2018 |
| Seniorsentrene Eiendomsutvikling AS | Real estate | 1988 |
| Seniorsentrene Holding AS | Real estate | 2006 |
| Seniorsentrene Holmestrand AS | Real estate | 2024 |
| Seniorsentrene Horten AS | Real estate | 2024 |
| Seniorsentrene Larvik AS | Real estate | 2024 |
| Seniorsentrene Lillehammer AS | Real estate | 2024 |
| Seniorsentrene Sandefjord AS | Real estate | 2001 |
| Sensor Advanced Technologies AS | Professional & scientific | 2021 |
| Senter Scene AS | Arts & recreation | 2018 |
| Sentrum Auto AS | Other services | 1981 |
| Sentrum Blikk Og Stål AS | Construction | 1992 |
| Sentrum Tannhelse Da | Health & social care | 2008 |
| Sergel Finans AS | Financial services | 2008 |
| Sergel Norge AS | Administrative & support | 2002 |
| Serrafina Holding AS | Financial services | 2013 |
| Serva AS | | 2025 |
| Servero AS | Hospitality | 2024 |
| Servicegutta AS | Administrative & support | 2017 |
| SFG AS | Real estate | 1985 |
| Sfiber Entreprenør AS | Construction | 2025 |
| SFN Equine AS | Arts & recreation | 2018 |
| SFN Holding AS | Hospitality | 2024 |
| Sha Og HMS Rådgiveren AS | Health & social care | 2021 |
| Shala Håndverk AS | Construction | 2026 |
| Shark AS | Transport & logistics | 2022 |
| Shee Holding AS | Real estate | 2005 |
| Shimmy AS | Administrative & support | 2020 |
| Shop IT Ans | Wholesale & retail | 1999 |
| Showcontrol AS | Information & communication | 2020 |
| Shs-Holding AS | Agriculture & fishing | 2019 |
| Si-Ro Invest AS | Wholesale & retail | 2010 |
| Sigma AS | Wholesale & retail | 1985 |
| Sigma Rør AS | Construction | 2025 |
| Signature Holding AS | Wholesale & retail | 2005 |
| Sihold AS | Real estate | 1989 |
| Sika Invest AS | Real estate | 1990 |
| Silje Norendal AS | Professional & scientific | 2020 |
| Silkeborg AS | Wholesale & retail | 2005 |
| Simba Toys Nordic AS | Wholesale & retail | 2005 |
| Simensen & Gullberg Holding AS | | 2019 |
| Simkil Holding AS | | 2026 |
| Singstad Innovation AS | Information & communication | 2019 |
| Sinopec Ami AS | Professional & scientific | 2017 |
| Sirkulært Kretsløp IP Nuf | Professional & scientific | 2022 |
| Siso Drift AS | Real estate | 2024 |
| Sisters Point Norge AS | Wholesale & retail | 2000 |
| Sitopama AS | | 2026 |
| Sivesind Trehjelp AS | Agriculture & fishing | 2021 |
| Sivuna AS | Education | 2009 |
| Sjue Bygg Og Eiendom AS | Construction | 2013 |
| Sjuvass AS | Real estate | 2021 |
| Sjuveenga Bryggelag SA | Real estate | 1982 |
| Sjøbris Holding AS | Real estate | 2010 |
| Sjøhusbrygga AS | Real estate | 2003 |
| Sjøstrand 6 AS | Real estate | 2019 |
| Sjøstrand 8-9 AS | Real estate | 2012 |
| Sjøtrollet AS | | 2022 |
| SK Bolig Og Eiendom AS | Real estate | 2014 |
| SK Montasje AS | Construction | 2010 |
| Sk-Invest AS | Financial services | 2018 |
| Skagerak Bolig AS | Real estate | 2014 |
| Skagerak Dampskibsselskap AS | Transport & logistics | 2021 |
| Skagerak Datacenter AS | Information & communication | 2021 |
| Skagerak Film AS | Information & communication | 2007 |
| Skagerak Invest AS | Wholesale & retail | 1991 |
| Skagerak Marine A1 AS | Wholesale & retail | 2023 |
| Skagerak Privatist AS | Education | 2020 |
| Skalleberg Graveservice AS | Construction | 2016 |
| Skallist AS | Real estate | 2005 |
| Skallist Gård AS | Agriculture & fishing | 2024 |
| Skallist Holding AS | | 2025 |
| Skallist Investment AS | Real estate | 2019 |
| Skap AS | Professional & scientific | 2012 |
| Skar Holding AS | Real estate | 2019 |
| Skar Luxe Visuals AS | Information & communication | 2024 |
| Skarsbakk Design AS | Professional & scientific | 2022 |
| Skarstaul AS | Real estate | 1992 |
| Skiferthorsen AS | Manufacturing | 1988 |
| Skilsø Invest AS | Professional & scientific | 1998 |
| Skilt Design Sandefjord AS | Manufacturing | 2005 |
| Skimmer AS | | 2023 |
| Skipenes Invest AS | Real estate | 2005 |
| SKJ Eiendom AS | Real estate | 2019 |
| Skjeggkrespesialisten AS | Administrative & support | 2025 |
| Skjelberg Moves AS | Education | 2018 |
| Skjellvika Miljø AS | Water & waste | 2009 |
| Skjelstad Montasje AS | Construction | 2012 |
| Skjerping AS | Professional & scientific | 2023 |
| Skjerven Accounting AS | Professional & scientific | 2016 |
| Skjerven Regnskap AS | Professional & scientific | 2015 |
| Skjld AS | | 2025 |
| Skjld Labs AS | Information & communication | 2026 |