| Sartaj AS | Wholesale & retail | 2020 |
| Sats Bygg AS | Construction | 2011 |
| Scandinavian Talent Development AS | Professional & scientific | 2006 |
| Scandinavian Veterinary Press AS | Information & communication | 2003 |
| Scandraft AS | Professional & scientific | 2011 |
| Scanfreight Air & Sea AS | Transport & logistics | 2022 |
| Scanfreight AS | Transport & logistics | 2017 |
| Schau Optik AS | Wholesale & retail | 2016 |
| Schrøder Larsen AS | Real estate | 2011 |
| Schweigaardsgate 60B AS | Real estate | 2006 |
| SCS Norway | Manufacturing | 2019 |
| Sebco AS | Real estate | 1984 |
| Seenew AS | Professional & scientific | 2013 |
| Segal AS | Wholesale & retail | 1980 |
| Seidel Invest AS | Real estate | 2005 |
| Seimbakken AS | | 2015 |
| Seisgate AS | Professional & scientific | 2022 |
| Selfiness AS | Arts & recreation | 2023 |
| Semaro AS | Professional & scientific | 2011 |
| Semille AS | | 2025 |
| Sevan AS | Wholesale & retail | 2016 |
| Sewell AS | Financial services | 2007 |
| SG Eiendom Invest AS | Real estate | 2014 |
| Shake Invest AS | | 2024 |
| Shanthi AS | Wholesale & retail | 2025 |
| Sharmas Indiske Restaurant Drøbak AS | Hospitality | 2023 |
| Sido Skredder AS | Other services | 2021 |
| Signatur Boligfoto AS | Professional & scientific | 2026 |
| Signe Veiteberg AS | Professional & scientific | 2019 |
| Sigo Holding AS | | 2026 |
| Sikrings Service Ans | | 1988 |
| Simply the Best AS | Hospitality | 2012 |
| Siriuskalven AS | | 1995 |
| Sisa Utvikling AS | Real estate | 2020 |
| Siso-Holding AS | | 2025 |
| Siv. Ing. Joachim Holm AS | Professional & scientific | 2014 |
| Sivilingeniør Sverre Christensen AS | Professional & scientific | 1997 |
| SJ Consulting AS | Professional & scientific | 2017 |
| Sjette AS | | 2020 |
| Skansen Økohus AS | Real estate | 2003 |
| Ski Øre-Nese-Hals AS | Health & social care | 2015 |
| Skilt & Folie AS | Manufacturing | 2020 |
| Skipperstuen Drøbak AS | Hospitality | 2025 |
| Skjeco AS | Wholesale & retail | 2025 |
| Skog Og Hagemaskiner AS | Wholesale & retail | 2008 |
| Skoglund Maskin AS | Construction | 2019 |
| Skogmo Dagligvare AS | Wholesale & retail | 2019 |
| Skogroveien 5 AS | Real estate | 2024 |
| Skogskjøtsel AS | Professional & scientific | 2019 |
| Skou Holding AS | Information & communication | 2025 |
| Skyum Consulting AS | Professional & scientific | 2018 |
| Slsd AS | Health & social care | 2021 |
| Slåke Invest Forvaltning AS | Professional & scientific | 2022 |
| Slåke Newco AS | Real estate | 2024 |
| Sman Bygg AS | Construction | 2015 |
| Smartlug AS | Manufacturing | 2026 |
| Smartsoil Biotech AS | Professional & scientific | 2020 |
| Smedsrud Mekaniske AS | Manufacturing | 2021 |
| Smithn Consulting AS | Professional & scientific | 2006 |
| SMT Service AS | Wholesale & retail | 2015 |
| Småbruket Berget AS | | 2020 |
| Smådyrklinikkens for Og Utstyr Da | Wholesale & retail | 1997 |
| Småhus-Spesialisten AS | Construction | 2004 |
| Snap Analytics AS | Information & communication | 2023 |
| Snekkergutta AS | Construction | 2016 |
| Snowkart AS | Wholesale & retail | 2022 |
| Sogsti Panorama AS | Real estate | 2012 |
| Sogstieika Barnehage SA | Education | 1995 |
| Sogstikollen Holding AS | Real estate | 2017 |
| Sogstiveien 2 AS | Real estate | 2016 |
| Solbergstrand Driftsselskap AS | Water & waste | 2009 |
| Solbergstrand Nordre Vann Og Avløp SA | Water & waste | 2023 |
| Solbergstrand Søndre Vann Og Avløp SA | Water & waste | 2010 |
| Solgry, Frelsesarmeens Barnehage I Drøbak AS | Education | 2022 |
| Solgård Design AS | Professional & scientific | 2016 |
| Solid Rørleggerservice AS | Construction | 2015 |
| Solsidan Invest AS | Information & communication | 2023 |
| Solv AS | | 2026 |
| Solveien 16 AS | Real estate | 2019 |
| Sommerseth Design AS | Professional & scientific | 2012 |
| Souar AS | Professional & scientific | 2022 |
| Spa Invest AS | | 2023 |
| Speedo Bilpleie Ans | Administrative & support | 1990 |
| Sport Store Ans | Wholesale & retail | 2007 |
| Sporten Drøbak AS | Wholesale & retail | 1995 |
| Sportia AS | Wholesale & retail | 2023 |
| Sportstek AS | Information & communication | 2017 |
| Spot Holding AS | | 2026 |
| Spre Holding AS | | 2020 |
| Sprinklerspesialisten AS | Construction | 2001 |
| Starboard Invest AS | Real estate | 2018 |
| Stars Aligned AS | Professional & scientific | 2011 |
| Start Eiendom AS | Real estate | 2000 |
| Statikk AS | Professional & scientific | 2022 |
| Stavellan Norway AS | Wholesale & retail | 2019 |
| Stavø Dagligvare AS | Wholesale & retail | 2026 |
| Steinmontering AS | Construction | 1995 |
| Steira Consulting AS | Professional & scientific | 2026 |
| Stener Invest AS | | 2026 |
| Sterk Kapital AS | Professional & scientific | 2024 |