| Sorak AS | Financial services | 2012 |
| Soria Labs AS | Information & communication | 2026 |
| Sosialkonsult Ans | Education | 1997 |
| Sossa Holding AS | | 2025 |
| South Hill Holding AS | | 2024 |
| Southwest Capital AS | Financial services | 2017 |
| Sovestudio AS | Wholesale & retail | 1990 |
| Specter Konsult AS | Professional & scientific | 2021 |
| Speed Invest AS | Real estate | 1981 |
| Speed Motorcenter AS | Wholesale & retail | 1980 |
| Speiz AS | Information & communication | 2020 |
| Sperrekvartalet AS | Real estate | 2007 |
| Spike-Holding AS | Wholesale & retail | 2023 |
| Spilder Eiendom AS | Real estate | 2022 |
| Spilder Holding AS | Education | 2005 |
| Spinn Kommunikasjon AS | Professional & scientific | 2016 |
| Spire AS | Real estate | 1957 |
| Spiritus AS | | 2024 |
| Spitz Holding AS | | 2006 |
| Splæsh AS | Information & communication | 2001 |
| Sport 1 Sandefjord AS | Wholesale & retail | 2023 |
| Sport for You Da | Wholesale & retail | 1999 |
| Spot Business Controlling AS | Professional & scientific | 2017 |
| Spotlight - Et Sted Å Bli Sett AS | Education | 2010 |
| Sprell Levende Produksjoner Ans | Arts & recreation | 2002 |
| Språkmagi Ans | Information & communication | 2025 |
| SR Transport AS | Transport & logistics | 2021 |
| SRH Invest Sandefjord AS | | 2013 |
| Staalnacke AS | Real estate | 2021 |
| Staffex AS | Administrative & support | 2024 |
| Stairs Music AS | Arts & recreation | 2009 |
| Stall Bergan AS | Wholesale & retail | 2000 |
| Stall Bergan Rideundervisning AS | Education | 2019 |
| Stall Bergan's Ride- Og Hesteutstyr Da | Wholesale & retail | 1996 |
| Stall Frode Hamre AS | Arts & recreation | 2001 |
| Stall Liberty AS | Agriculture & fishing | 2024 |
| Stall Søvik Nuf | Arts & recreation | 2008 |
| Stamper Holding AS | Transport & logistics | 2023 |
| Stand AS | Professional & scientific | 2021 |
| Stand Eiendom AS | Real estate | 2022 |
| Stanghjørnet AS | Wholesale & retail | 1991 |
| Starflex AS | Wholesale & retail | 2022 |
| Stargate Studios AS | Information & communication | 1996 |
| Starvin Marvin AS | Administrative & support | 2020 |
| Stash AS | Information & communication | 2023 |
| Statika AS | Arts & recreation | 2022 |
| Staud Ansatte AS | | 2025 |
| Staud Gruppen AS | Professional & scientific | 2023 |
| Stauper AS | Real estate | 1987 |
| Stauper Invest AS | Real estate | 2015 |
| Staven Alpin AS | Real estate | 2026 |
| Stavern Engineering AS | Professional & scientific | 1985 |
| Stavernsodden Bidco AS | | 2023 |
| Stavsmark AS | Real estate | 2005 |
| Steen Aviation AS | Administrative & support | 2022 |
| Steen Konsern AS | Administrative & support | 2022 |
| Steimler Holding AS | Financial services | 2011 |
| Stein Lysthaug AS | Wholesale & retail | 2003 |
| Stein Trygsland Holding AS | | 2026 |
| Steinar Jacobsen AS | Professional & scientific | 2005 |
| Steinbo Bemanning AS | Administrative & support | 2020 |
| Steinbo Eiendom AS | Real estate | 1989 |
| Steinbo Hasle AS | Real estate | 2018 |
| Steinbo Kastet AS | Real estate | 1999 |
| Steinbo Nord AS | Real estate | 2000 |
| Steinbo Regnskap AS | Professional & scientific | 2014 |
| Steinbo Sør AS | Real estate | 2011 |
| Steinbo Øst AS | Real estate | 2013 |
| Steinsett Holding AS | Professional & scientific | 2005 |
| Stella Polaris Opplevelser AS | Arts & recreation | 2006 |
| Sten Eiendom AS | Real estate | 2017 |
| Sten Holding AS | Real estate | 2017 |
| Stenersen Bolig AS | Real estate | 2013 |
| Step Bolig AS | Real estate | 2009 |
| Step Eiendomsutvikling AS | Real estate | 2002 |
| Step Prosjekt AS | Real estate | 2009 |
| Step Prosjektutvikling AS | Real estate | 2002 |
| Sterkpappa AS | Health & social care | 2025 |
| STH Multiservice AS | Administrative & support | 2016 |
| Sti Holding AS | | 2012 |
| Sti-Invest AS | Construction | 2017 |
| Stian Data AS | Information & communication | 2013 |
| Stickler Breivik Engineering AS | Professional & scientific | 1991 |
| Stiftet Holding AS | Professional & scientific | 2025 |
| Stigemannen AS | Wholesale & retail | 2022 |
| Stigenvegen Veglag SA | Real estate | 1981 |
| Stima Invest AS | | 2012 |
| Stina Invest AS | Professional & scientific | 2022 |
| Stjernehus AS | Real estate | 2020 |
| STK Service AS | Construction | 2022 |
| Stm-Holding AS | | 2023 |
| Stockflethsgate 22 AS | Real estate | 1954 |
| Stokke Hageby AS | Real estate | 2006 |
| Stone Image AS | Manufacturing | 2015 |
| Stonehouse Property AS | Real estate | 2026 |
| Storgata 10 B. AS | Real estate | 2000 |
| Storgata 2 Kontor AS | Real estate | 2017 |
| Storgata 3-5 AS | Real estate | 2017 |
| Storgata 96 Eiendom AS | Real estate | 2007 |
| Storgata Kontordrift AS | Administrative & support | 2018 |