| Rør Tech Holding AS | Construction | 2024 |
| Røra Holding AS | Real estate | 2008 |
| Røraskogen 16 AS | Real estate | 2019 |
| Røraskogen 18 AS | Real estate | 2008 |
| Rørgutta Skien AS | Construction | 2016 |
| Rørlegger Gulliksen AS | Construction | 2016 |
| Rørlegger Sivertsen AS | Construction | 2014 |
| Rørlegger Sivertsen Byggtjenester AS | Construction | 2014 |
| Rørlegger Thomas Westgård AS | Construction | 2006 |
| Rørleggermester Nærum AS | Construction | 2011 |
| Rørvik Invest AS | | 2016 |
| Rørviknow AS | Education | 2019 |
| S Graver AS | Wholesale & retail | 1997 |
| S&S Solutions AS | | 2022 |
| S. Øverås Holding AS | Real estate | 2020 |
| S.E Solutions AS | Construction | 2023 |
| S.G Holding AS | Real estate | 2012 |
| S.M.Ventilasjon AS | Construction | 2014 |
| S4 Gruppen AS | Real estate | 2022 |
| Sabrura Herkules AS | Hospitality | 2021 |
| Sachnowitz Vei 12 AS | Real estate | 2022 |
| Sada Holding AS | Other services | 2017 |
| Sadoun Barbershop AS | Other services | 2024 |
| Safe Exit AS | Manufacturing | 2009 |
| Safe Exit Eiendom AS | Manufacturing | 2012 |
| Safran Mat AS | Wholesale & retail | 2021 |
| Sag AS | Wholesale & retail | 2005 |
| Saga Chokoladefabrikk AS | Manufacturing | 2007 |
| Saga Mat AS | Wholesale & retail | 2001 |
| Sagaklinikk AS | Health & social care | 2012 |
| Sageie Holding AS | Wholesale & retail | 2005 |
| Saglandet Eiendom AS | Construction | 2013 |
| Sagvolden AS | Wholesale & retail | 2006 |
| Salmaker'N Da | Other services | 2026 |
| Salong Arena AS | Other services | 2010 |
| Salong Gregorius AS | Other services | 2018 |
| Salongen På Landet AS | Other services | 2020 |
| Salora AS | Information & communication | 2026 |
| Saltvoll Holding AS | | 2023 |
| Salus Consult AS | Professional & scientific | 2025 |
| Salvare AS | Real estate | 2009 |
| Sammu AS | Real estate | 1990 |
| Samsvarspartner AS | Health & social care | 2023 |
| Sandakervegen 23A AS | Real estate | 2013 |
| Sanderød Holding AS | Construction | 2020 |
| Sanderød Rør AS | Construction | 2024 |
| Sandkjenn Skogveilag SA | Real estate | 2017 |
| Sannes Bygg AS | Construction | 2014 |
| Sanni AS | | 2021 |
| Sanni Eiendom AS | Real estate | 2019 |
| Sanssoucivegen 18 AS | Real estate | 2022 |
| Sara Boutique AS | Wholesale & retail | 1997 |
| Sara Orientalske Tepper AS | Manufacturing | 2016 |
| Satyr Holding AS | Real estate | 2016 |
| Saubrekka Holding AS | | 2020 |
| Savicon AS | Construction | 2022 |
| Savicon Holding AS | Construction | 2022 |
| Sb-Invest AS | Financial services | 2018 |
| Sbi Design AS | Professional & scientific | 1997 |
| Sbmolvik AS | | 2024 |
| Sbygg AS | Construction | 2014 |
| Scan Flyfoto AS | Real estate | 1994 |
| Scand-Ind Trading Da | Wholesale & retail | 1989 |
| Scano Marketing AS | | 1997 |
| Scanseis Consulting Group AS | Professional & scientific | 2003 |
| Scape Management AS | Information & communication | 2016 |
| Scheen AS | Professional & scientific | 2019 |
| Scheen Eiendom AS | Real estate | 2012 |
| Scheen Industrigulv AS | Construction | 2020 |
| Schia AS | Real estate | 2005 |
| Schillinger AS | Real estate | 2005 |
| Schriwer Eiendom Ans | Real estate | 2004 |
| Schweigaards Plass Næring AS | Real estate | 2013 |
| Schøne Invest AS | Professional & scientific | 2021 |
| Seax El. Installasjon AS | Construction | 2004 |
| Sebastien Holding AS | | 2026 |
| Sectech AS | Construction | 2009 |
| Seismic Consultant AS | Professional & scientific | 2005 |
| Sekk AS | Information & communication | 2017 |
| Select Bil AS | Wholesale & retail | 2020 |
| Selvskapet AS | Professional & scientific | 2024 |
| Sem Seterskog AS | Agriculture & fishing | 2011 |
| Semi Eiendom Da | Real estate | 2005 |
| Semsvegen 37 AS | Real estate | 2025 |
| Senmor AS | Real estate | 1996 |
| Sensato AS | Education | 2024 |
| Sensosoft AS | Information & communication | 2015 |
| Senter Eiendom Da | Real estate | 2011 |
| Senter Eiendom II Da | Real estate | 2010 |
| Senter Holding AS | Administrative & support | 2023 |
| Senterutleie AS | Administrative & support | 2023 |
| Sentrum Eiendom Telemark AS | Real estate | 2010 |
| Sentrum Legesenter Skien AS | Health & social care | 2015 |
| Servom AS | Other services | 2015 |
| Seven Catering Da | Hospitality | 1996 |
| Seven Stones Nordic AS | Professional & scientific | 2018 |
| SG Solutions AS | Professional & scientific | 2026 |
| Sg-Utvikling AS | Real estate | 2019 |
| Sgi Eiendom AS | Real estate | 2011 |
| Sgi Invest AS | | 2025 |