| Shekho AS | Hospitality | 2025 |
| Shibesoft AS | Information & communication | 2016 |
| Shiki Sushi Bar AS | Hospitality | 2012 |
| Shine Renhold Khan AS | Administrative & support | 2020 |
| Short Holdings AS | Information & communication | 2021 |
| Showfabrikken Media AS | Information & communication | 2010 |
| Si-Ko AS | Other services | 2019 |
| Siam AS | Hospitality | 2019 |
| Siartic AS | | 2023 |
| Sias Rubro AS | Real estate | 2013 |
| Sibeo AS | Professional & scientific | 2015 |
| Signalsapi AS | Information & communication | 2025 |
| Signup Software AS | Information & communication | 2023 |
| Sildring Capital AS | | 2020 |
| Silva Borealis AS | Professional & scientific | 2023 |
| Simali AS | | 2019 |
| Sinding Eiendom AS | Real estate | 2022 |
| Sinding Gruppen AS | Professional & scientific | 2019 |
| Singdahlsen AS | Professional & scientific | 2018 |
| Siti Eiendom AS | Real estate | 2022 |
| Siv. Ing. Living AS | | 2020 |
| Siv.Ing Hjortaas AS | Professional & scientific | 2021 |
| Sivet AS | Real estate | 2021 |
| Sivilingeniør Sverre Steen AS | Professional & scientific | 1994 |
| Sivilingeniørene Julsen & Poppe AS | Professional & scientific | 2005 |
| Sjømannsgt 7 AS | Construction | 2007 |
| Skade Og Lakk AS | Other services | 2000 |
| Skagen Investering AS | | 2021 |
| Skagerrak Marintek AS | Professional & scientific | 2020 |
| Skaldekvad AS | Information & communication | 2016 |
| Skanlab AS | Manufacturing | 1996 |
| Skansen Agenturer Nuf | Real estate | 2010 |
| Skard Solhaug Invest AS | Real estate | 2017 |
| Skauen Holding AS | Manufacturing | 2018 |
| Skauen Ventures AS | | 2025 |
| SKB Invest AS | Real estate | 2011 |
| Ske AS | Real estate | 2005 |
| Skendo Renhold AS | Administrative & support | 2010 |
| Skilt Og Dekor AS | Professional & scientific | 1987 |
| Skiltservice AS | Manufacturing | 2012 |
| Skin Wise AS | Other services | 2023 |
| Skincare Junkie AS | Arts & recreation | 2016 |
| Skipsnett Da | Information & communication | 2001 |
| Skjerviken AS | Construction | 2005 |
| Skjerviken Rør AS | Construction | 2003 |
| Skoagentene AS | Wholesale & retail | 2013 |
| Skomaker'N I Fredrikstad AS | Other services | 1987 |
| Skomannen AS | Wholesale & retail | 2020 |
| Skorsteinspesialisten AS | Construction | 2013 |
| Skrifthuset AS | Information & communication | 1999 |
| Skullerud Flyttebyrå AS | Transport & logistics | 1991 |
| Skydive Blackhawk AS | Administrative & support | 2022 |
| Skyhi AS | | 2023 |
| Skytterhusveien Og Gamle Tveteveien Veilag SA | Real estate | 2018 |
| Skyward AS | Transport & logistics | 2013 |
| Slavianor AS | Real estate | 1990 |
| Sleipner Gressvik AS | Real estate | 2017 |
| Sleipner Motor AS | Manufacturing | 1977 |
| Sleipner Motor Eiendom AS | Real estate | 2015 |
| Sletten Invest AS | Financial services | 2012 |
| Smaart Solution AS | Wholesale & retail | 2026 |
| Smart Energi AS | Energy | 2010 |
| Smartvarsling Drift AS | Wholesale & retail | 2017 |
| Smartwaves AS | Information & communication | 2017 |
| Smillebra AS | Health & social care | 2024 |
| Smistad AS | Real estate | 2020 |
| Smoods Bar & Bistro AS | Hospitality | 2011 |
| Smæsh Burger AS | Hospitality | 2018 |
| Snippen Bar Da | Hospitality | 2025 |
| Snowlion AS | Professional & scientific | 2016 |
| Snowlion Holding AS | Professional & scientific | 1993 |
| Snowlion Invest AS | Professional & scientific | 2011 |
| Snø AS | Professional & scientific | 2005 |
| Sodai AS | Wholesale & retail | 2013 |
| Sofa Production AS | Information & communication | 2026 |
| Sofood Sofun AS | Hospitality | 2025 |
| Software Engineering Gøteborg AB | Professional & scientific | 1995 |
| Solarport AS | Professional & scientific | 2021 |
| Solberg Holding Eiendom AS | Real estate | 2018 |
| Solberg Industri AS | Manufacturing | 1966 |
| Solberg Industri Holding AS | Manufacturing | 1979 |
| Solberg Snø Og Grønt AS | Agriculture & fishing | 2001 |
| Solcelleeksperten AS | Construction | 2022 |
| Solens Forlag AS | Manufacturing | 2012 |
| Solgårds Eiendomsselskap AS | Real estate | 2014 |
| Soli Auto AS | Wholesale & retail | 2024 |
| Solmoen Invest AS | | 2026 |
| Solveig Egeland Holding AS | | 2024 |
| Someday AS | Financial services | 2014 |
| Something Odd AS | Information & communication | 2014 |
| Sommer I Fredrikstad AS | Arts & recreation | 2021 |
| Sonnino Eiendom AS | Real estate | 2007 |
| Sorl AS | Arts & recreation | 1997 |
| Soulsinger AS | Arts & recreation | 2024 |
| Spa Holding AS | Real estate | 2003 |
| Spilldall AS | Wholesale & retail | 2020 |
| Spinoza AS | Education | 1995 |
| Sport Auto Events AS | Administrative & support | 2013 |
| Sport Event AS | Wholesale & retail | 1997 |
| SRS Lokal TV Da | Information & communication | 1993 |