| Scouse Holding AS | | 2019 |
| Sea Trade Invest AS | Financial services | 2005 |
| Seba Holding AS | Financial services | 2018 |
| Sebrio AS | | 2025 |
| Sebsn Holding AS | | 2019 |
| Sei AS | Financial services | 2013 |
| Seilerhytta Restaurant AS | Hospitality | 2022 |
| Selander AS | Financial services | 2017 |
| Selector AS | Administrative & support | 2022 |
| Selector Finance AS | Professional & scientific | 2025 |
| Selector Search AS | Administrative & support | 2025 |
| Seljord Næringspark AS | Real estate | 2021 |
| Seljord Utvikling AS | Real estate | 2013 |
| Semb Skogservice AS | Manufacturing | 2021 |
| Senorita Style AS | Other services | 1982 |
| Sens-Eiendom AS | Real estate | 2022 |
| Senter for Integral Mindfulness Da | Education | 2020 |
| Sentrum Tannklinikk AS | Health & social care | 2001 |
| Sentrum-Legekontor Ans | Health & social care | 2005 |
| Sentrumsboden AS | Real estate | 2020 |
| Seplama AS | Wholesale & retail | 1996 |
| Seppänen Holding AS | | 2024 |
| Serkland AS | Water & waste | 2016 |
| SG Drift AS | Construction | 2022 |
| Sha Invest AS | Real estate | 2007 |
| Sharmila AS | Hospitality | 2018 |
| Sheshe Bolig AS | Real estate | 2009 |
| Sheshe Eiendom AS | Real estate | 2004 |
| Sheshe Holding AS | Real estate | 2005 |
| Sheshe Lager AS | Real estate | 2022 |
| Shipping Publications AS | Information & communication | 1994 |
| SHM Invest AS | Real estate | 2000 |
| Shreds AS | Professional & scientific | 2025 |
| Siben Consult AS | Professional & scientific | 2017 |
| Siblerk Tre AS | Wholesale & retail | 2011 |
| Siekacz Vaktmester Service AS | Administrative & support | 2012 |
| Siggis Travel and F&B Service AS | Administrative & support | 2022 |
| Sigurd Eiendom AS | Real estate | 2023 |
| Sigurds Gate 4 Larvik AS | Real estate | 2016 |
| Sigurdsgate 7 AS | Administrative & support | 1991 |
| Sigurdsgate Eiendom AS | Real estate | 2008 |
| Siiv AS | Real estate | 2005 |
| Sikkerhetsopplæring AS | Education | 2023 |
| Siljuvannsåsen SA | Water & waste | 2020 |
| Simedia AS | Information & communication | 2019 |
| Simo Elektro Entreprenør AS | Construction | 2025 |
| Simon E. Haugen Transport AS | Transport & logistics | 2016 |
| Singer Sysenter Larvik AS | Wholesale & retail | 2018 |
| Sinwest AS | | 2025 |
| Sirkulær AS | Professional & scientific | 2020 |
| Siv.Øk Thore Arne Olsen AS | Professional & scientific | 2020 |
| SJ Bygg Og Våtrom AS | Construction | 2023 |
| Sjel by Hvaal Studio AS | Wholesale & retail | 2024 |
| Sjur Ørseng AS | Professional & scientific | 2025 |
| Sjølyst Holding AS | Construction | 2005 |
| Sjøslag Restaurant AS | Hospitality | 2021 |
| Sjøøstens AS | | 2023 |
| SK Maling AS | Construction | 2024 |
| SK Takfornying AS | Construction | 2023 |
| Sk-Pumper AS | Manufacturing | 2010 |
| Skagerak Eiendom AS | Real estate | 2020 |
| Skagerrak-Eiendom AS | Real estate | 2017 |
| Skaginor AS | Real estate | 2007 |
| Skalleberg Malerservice AS | Construction | 2026 |
| Skan-Tre AS | Professional & scientific | 2012 |
| Skan-Tre Eiendom AS | Real estate | 2012 |
| Skandinaviska Tre Och Stålprodukter AB | Wholesale & retail | 1997 |
| Skattekista Barnehage SA | Education | 1999 |
| Skeidar Larvik AS | Wholesale & retail | 1998 |
| Skibåsen 36 AS | Real estate | 1985 |
| Skilt Og Fasadevask Hermansen Og Larsen Ans | Administrative & support | 1988 |
| Skilt Senteret Larvik AS | Manufacturing | 1992 |
| Skinmedic Larvik AS | Other services | 2020 |
| Skinmo Eiendom AS | Real estate | 2007 |
| Skipperløkka Da | Wholesale & retail | 2018 |
| Skipsfjell AS | Real estate | 2020 |
| Skiringsalsgate 32 AS | Construction | 2021 |
| Skissebua AS | Real estate | 2021 |
| Skivik Teknikk AS | Professional & scientific | 2024 |
| Skjold Holding AS | Professional & scientific | 2007 |
| Skjærgårdshagen AS | Agriculture & fishing | 2026 |
| Skobi Gjemsø AS | Wholesale & retail | 1991 |
| Skog & Åkerdrone AS | Professional & scientific | 2026 |
| Skog Blomsterverksted AS | Wholesale & retail | 2021 |
| Skogvegen 8 Lunde AS | Real estate | 2012 |
| SKOLEGATA-1 AS | Real estate | 2021 |
| Skolesystemer AS | Information & communication | 2025 |
| Skoleveien 9-11 AS | Real estate | 2022 |
| Skolmar 19 AS | Real estate | 1994 |
| Skotta Holding AS | Construction | 2014 |
| Skreppestad Senteret AS | Real estate | 2012 |
| Skreppestadveien 24 AS | Real estate | 1971 |
| Skreppestadveien 45 AS | Real estate | 2014 |
| Skreppestadveien 50 AS | Real estate | 2022 |
| Skrivergården AS | Real estate | 1976 |
| Skuggedal AS | Professional & scientific | 2023 |
| Skuld Familieholding AS | Real estate | 2018 |
| SL Engineering & Invest AS | Professional & scientific | 2018 |
| Smart Unique Travel AS | Administrative & support | 2023 |
| Smartvatten AS | Professional & scientific | 2022 |