| Strømsbu Platå AS | Real estate | 2018 |
| Strømsø AS | Hospitality | 2022 |
| Strømsø Auto Senter AS | Wholesale & retail | 1996 |
| Strømsø Café AS | Hospitality | 2025 |
| Strømsø Dagligvare AS | Wholesale & retail | 2025 |
| Strømsø Fysikalske Institutt Da | Health & social care | 1991 |
| Strømsø Halal Kjøtthall AS | Wholesale & retail | 2016 |
| Strømsø Legegruppe Da | Health & social care | 2007 |
| Strømsø Musikk AS | Wholesale & retail | 2023 |
| Strømsø Nails AS | Other services | 2025 |
| Strømsø Panorama AS | Hospitality | 2023 |
| Strømsø Plaza AS | Hospitality | 2016 |
| Strømsø Sport AS | Wholesale & retail | 2021 |
| Strømsø Torg Eiendom AS | Real estate | 2012 |
| Strømsø United AS | Real estate | 2021 |
| Strømsø Utleie Og Eierskap AS | Real estate | 2024 |
| Strøtvedtbygg AS | Real estate | 1964 |
| Strøtvet AS | Professional & scientific | 2003 |
| Strøtvet Consulting AS | Real estate | 2007 |
| Stubberudveien Invest AS | | 2024 |
| Studio 69 AS | Real estate | 2026 |
| Studio Lille Drammen AS | Education | 2023 |
| Studio Tre AS | Other services | 2025 |
| Studio V47 AS | Information & communication | 2026 |
| STUDIO75 AS | Real estate | 2020 |
| Stuk AS | | 2022 |
| Stykket Holding AS | Real estate | 2009 |
| Stylizimo AS | Information & communication | 2012 |
| Styrkefabrikken AS | Education | 2022 |
| Ståle Solbakken | Education | 2013 |
| Stærkeby Takst AS | Professional & scientific | 2009 |
| Støa Eiendom AS | | 2012 |
| Støa Håndverk AS | Construction | 1989 |
| Støa Verdi AS | Construction | 1973 |
| Stølan Holding AS | | 2022 |
| Su Sushi Bar AS | Hospitality | 2021 |
| Sub Seatech Contracting Corp | Wholesale & retail | 2003 |
| Subsea Oil Solutions AS | Professional & scientific | 2012 |
| Suited AS | Real estate | 2017 |
| Sulgoja Oü Nuf | Construction | 2024 |
| Sulland Bil Drammen AS | Other services | 1956 |
| Sulland Drammen AS | Wholesale & retail | 2001 |
| Sumbra AS | Professional & scientific | 2025 |
| Summerbird | Manufacturing | 2013 |
| Summit Holding AS | Professional & scientific | 2019 |
| Sunda Eiendom AS | Real estate | 2011 |
| Sunde Utvikling AS | Professional & scientific | 2019 |
| Sundsmoen Holding AS | Financial services | 2007 |
| Sundtjønnlia Vann Og Veilag SA | Water & waste | 2018 |
| Sunland-Eker Eiendom AS | Real estate | 2017 |
| Sunnere AS | Wholesale & retail | 2026 |
| Superfresh AS | Wholesale & retail | 2012 |
| Supplement AS | Administrative & support | 2023 |
| Sushi City Wok AS | Hospitality | 2014 |
| Suzuki Bilimport AS | Wholesale & retail | 1983 |
| Svane Kjøkkenet Drammen AS | Wholesale & retail | 2023 |
| Svanegangen AS | Real estate | 2016 |
| Svanegangen Utvikling AS | Real estate | 2016 |
| Svar Consulting AS | Information & communication | 2025 |
| Svart Asfalt AS | Construction | 2021 |
| Svart Stein AS | Construction | 2019 |
| Svarterud AS | Hospitality | 2025 |
| Svartkjele AS | | 2025 |
| Svartåsveien 17 AS | Real estate | 2016 |
| Svea Group AS | Wholesale & retail | 2015 |
| Svea Maskiner AS | Wholesale & retail | 1970 |
| Svea Service AS | Wholesale & retail | 1987 |
| Sveinung Kristiansen Holding AS | Wholesale & retail | 2020 |
| Sveisesenteret AS | Wholesale & retail | 1989 |
| Sveisesenteret Holding AS | | 2005 |
| Svelvik Bolig AS | Real estate | 2020 |
| Svelvik Helsetjenester AS | Health & social care | 1992 |
| Svelvikveien 61 AS | Real estate | 2013 |
| Svendsvoll Holding AS | | 2021 |
| Svenibona-Nina AS | | 2021 |
| Svensedammen Legesenter AS | Health & social care | 2013 |
| Svensson Nøkleby Advokatfirma Ans | Professional & scientific | 2000 |
| Svent AS | Construction | 2022 |
| Svent Holding AS | Construction | 2020 |
| Svent Service AS | Construction | 2020 |
| Sverre Nielsen Transportforretning AS | Transport & logistics | 1988 |
| Sweetella AS | Hospitality | 2022 |
| Swetech AS | Professional & scientific | 2022 |
| Swietelsky AG | Construction | 2010 |
| Swietelsky Rail Norway AS | Construction | 2011 |
| Swopp AS | Transport & logistics | 2024 |
| Sydney Grill AS | Hospitality | 2018 |
| Symo Holding AS | Health & social care | 2023 |
| Synchrocity AS | Professional & scientific | 2016 |
| Synovia AS | Health & social care | 2000 |
| Synsdu AS | Professional & scientific | 2015 |
| Synsenteret Drammen AS | Wholesale & retail | 2013 |
| Syretårnet 31 AS | Real estate | 2005 |
| Syretårnet 39 AS | Real estate | 2024 |
| Syretårnet 41 AS | Real estate | 1983 |
| Syretårnet AS | Real estate | 2020 |
| Systua AS | Manufacturing | 1995 |
| Syt AS | Real estate | 2023 |
| Syvess AS | Real estate | 2018 |
| Saturn Eiendom A/S | Manufacturing | 1946 |