| Sims Holding AS | | 2019 |
| Sindi AS | | 2016 |
| Sirus Eiendom AS | Real estate | 2022 |
| Siu Holding AS | | 2024 |
| SK Holdning AS | | 2024 |
| Skagen Bil AS | Wholesale & retail | 2016 |
| Skarelven & Teigland Da | Wholesale & retail | 2003 |
| Skeidar Strømmen AS | Wholesale & retail | 1998 |
| Skorep AS | Other services | 2015 |
| Smart Transport Og Logistikk AS | Transport & logistics | 2023 |
| Smarte AS | Wholesale & retail | 2023 |
| Smiervuotna AS | Professional & scientific | 2006 |
| Smit Invest AS | | 2019 |
| Snekker & Montasje Mester AS | Construction | 2026 |
| Snekker Prosjekt AS | Construction | 2019 |
| Snos Strømmen AS | Wholesale & retail | 2022 |
| Soleon Invest AS | | 2026 |
| Solid Renhold & Vedlikehold AS | Administrative & support | 2011 |
| Solskjermingshuset AS | Construction | 2021 |
| Solutech AS | Wholesale & retail | 2014 |
| Sorodi Capital AS | Wholesale & retail | 2014 |
| Sorrento Pizza Restaurant AS | Hospitality | 2021 |
| Spekter Malerfirma AS | Construction | 2012 |
| Sportstad Auto AS | Administrative & support | 2013 |
| Stalsberg Eiendom AS | Real estate | 2015 |
| Stasjonsdrift Iaktra AS | Transport & logistics | 2023 |
| Steer Consulting AS | Health & social care | 2012 |
| Storkiosk NR 26 Sagdalen Ans | Wholesale & retail | 2000 |
| Storkiosk Sagdalen Ans | Wholesale & retail | 1993 |
| Storvik Byggtjeneste AS | Construction | 2007 |
| Straight Lines AS | Construction | 2024 |
| Strandveien 1 AS | Real estate | 1965 |
| Strandveien 1 Utvikling AS | Real estate | 2017 |
| Stride AS | | 2024 |
| Striker Wear AS | Wholesale & retail | 2019 |
| Stråh AS | Other services | 2023 |
| Strøjobber AS | Administrative & support | 2024 |
| Strømmen Auto Care AS | Other services | 2019 |
| Strømmen Bakeri AS | Manufacturing | 2019 |
| Strømmen Bilforhandler AS | Wholesale & retail | 2025 |
| Strømmen Billakk AS | Other services | 2014 |
| Strømmen Bilradio AS | Wholesale & retail | 2007 |
| Strømmen Bilverksted AS | Other services | 2014 |
| Strømmen Bolig Varmepumpe AS | Construction | 2016 |
| Strømmen Bygg Og Montasjeservice AS | Construction | 1988 |
| Strømmen Byggepartnere AS | Construction | 2024 |
| Strømmen Dentallab AS | Manufacturing | 1994 |
| Strømmen Eiendomsmegling AS | Real estate | 2013 |
| Strømmen El-Installasjon AS | Construction | 2001 |
| Strømmen Elektro AS | Construction | 1997 |
| Strømmen Engros AS | Wholesale & retail | 2003 |
| Strømmen Fried Chicken Og Pizza AS | Hospitality | 2020 |
| Strømmen Halal Kjøtt AS | Wholesale & retail | 2025 |
| Strømmen Hjemmebrygg AS | Wholesale & retail | 2012 |
| Strømmen Husflid AS | Wholesale & retail | 2022 |
| Strømmen Legesenter AS | Health & social care | 2014 |
| Strømmen Leker AS | Wholesale & retail | 2015 |
| Strømmen Mat AS | Wholesale & retail | 2024 |
| Strømmen Pizza Ans | Hospitality | 1991 |
| Strømmen Pizza Service AS | Hospitality | 2013 |
| Strømmen Pizzadrift AS | Hospitality | 2024 |
| Strømmen Rørleggerbedrift AS | Construction | 1998 |
| Strømmen Skjønnhet Og Velvære AS | Other services | 2025 |
| Strømmen Sparebank | Financial services | 1921 |
| Strømmen Staal Restaurant & Bar AS | Hospitality | 2015 |
| Strømmen Sushi & Thai Mat AS | Hospitality | 2014 |
| Strømmen Synssenter AS | Wholesale & retail | 2022 |
| Strømmen Tannhelse Og Tannlegevakt AS | Health & social care | 2018 |
| Strømmen Tannlegesenter AS | Health & social care | 2019 |
| Strømmen Tele AS | Wholesale & retail | 2001 |
| Strømmen Ur Og Smykker AS | Wholesale & retail | 2003 |
| Strømmenklinikken AS | Health & social care | 2010 |
| Strømsnes Holding AS | Financial services | 2016 |
| Strømsparken Pizza AS | Hospitality | 2007 |
| Strømsveien 163 AS | Real estate | 2016 |
| Strømsveien 81 Næring AS | Real estate | 2022 |
| Strømsveien Kbng AS | Real estate | 2017 |
| Studded Possum AS | Arts & recreation | 2026 |
| Sultan HT Holding AS | | 2024 |
| Sultan Marked AS | Wholesale & retail | 1996 |
| Sushi Og Varmmat Maris AS | Hospitality | 2026 |
| SV Byggteknikk AS | Real estate | 2023 |
| Sveum AS | Manufacturing | 2026 |
| Swa Holding AS | | 2026 |
| Sweetspot AS | Wholesale & retail | 2015 |
| Syakademiet AS | Manufacturing | 2013 |
| Systue Ram AS | Manufacturing | 2017 |
| Sølenskaret AS | | 2023 |
| Sørlie Forvaltning AS | Real estate | 2005 |
| Tannlege Christian Andersson AS | Health & social care | 2021 |
| Tannlege Torkild Stjernesund AS | Health & social care | 2021 |
| Tbo Holding AS | Wholesale & retail | 2022 |
| Techprovider AS | Administrative & support | 2016 |
| Teen Invest AS | | 2024 |
| Teknisk Etterforskning AS | Professional & scientific | 2011 |
| Telerådgiverne Ans | Information & communication | 2006 |
| Teppesalongen AS | Construction | 1974 |
| Teppesalongen Holding AS | | 2005 |
| Tere Rang Da | Hospitality | 2010 |
| Terje Halvorsen Holding AS | | 2022 |