| Røsholmen Vann & Avløp SA | Water & waste | 2004 |
| Sales Expansion AS | Professional & scientific | 2025 |
| Saltvik Vann- Og Avløpslag SA | Water & waste | 2016 |
| Sirvente AS | Professional & scientific | 1996 |
| Skjærhalden Bygg AS | Construction | 2014 |
| Skjærhalden Båtsenter AS | Manufacturing | 2021 |
| Skjærhalden Båtsenter Service Ans | Manufacturing | 1989 |
| Skjærhalden Eiendom AS | Real estate | 1974 |
| Skjærhalden Fiskemottak AS | Manufacturing | 2015 |
| Skjærhalden Gjestehavn AS | Arts & recreation | 2005 |
| Skjærhalden Helsetun AS | Real estate | 2020 |
| Skjærhalden Holding AS | Wholesale & retail | 2018 |
| Skjærhalden Invest AS | Real estate | 2002 |
| Snekotta Gård Da | Agriculture & fishing | 2021 |
| Solbakken Invest 2 AS | Professional & scientific | 2012 |
| Solvik Vann- Og Avløpslag SA | Water & waste | 2017 |
| Sperlin AS | Construction | 2017 |
| Storm Østers AS | Agriculture & fishing | 2018 |
| Storrødbrygga Vann- Og Avløpslag SA | Water & waste | 2013 |
| Strandveien 8 AS | Hospitality | 2024 |
| Stri Media AS | Information & communication | 2018 |
| Symfoni Software AS | Information & communication | 1997 |
| Sørensen & Eriksen Ans | Transport & logistics | 2005 |
| Tegnespesialisten AS | Professional & scientific | 2017 |
| Tenk Digitalt AS | Information & communication | 2012 |
| The Box AS | Real estate | 2012 |
| Torget 1 Eiendomsselskap AS | Real estate | 2006 |
| Tre Ønsker AS | Professional & scientific | 2016 |
| Tre Ønsker Holding AS | | 2025 |
| Tulla AS | Real estate | 2014 |
| Under Kollen 1 AS | Real estate | 2022 |
| Under Kollen 2 AS | Real estate | 2023 |
| Vonrosen Holding AS | Real estate | 2013 |
| VS Medica AS | Health & social care | 2025 |
| VVS & Eiendom AS | Construction | 2023 |