| Schou Salong AS | Other services | 2017 |
| SDM Eiendom AS | Real estate | 2026 |
| SDM Holdings AS | | 2025 |
| Serigstad Holding AS | Financial services | 2015 |
| Sigve Simonsen AS | Construction | 2013 |
| Sildring AS | Financial services | 2005 |
| Simonsen's Eiendom AS | Wholesale & retail | 2007 |
| Simonsen's Utleie AS | Administrative & support | 2017 |
| Simonsens Butikkdrift AS | Wholesale & retail | 2007 |
| Sjølingstad Trapp Og Snekkerverksted AS | Manufacturing | 2024 |
| Sjøsprøyt Båly AS | Agriculture & fishing | 2014 |
| Skagestad Takst Og Eiendom AS | Real estate | 2022 |
| Skarpnes Boats AS | Manufacturing | 2001 |
| Skogheim Drift Da | Agriculture & fishing | 2011 |
| Skoies Eiendom 2 AS | Real estate | 2022 |
| Skomrak AS | Real estate | 2009 |
| Snekkerfirma Jan Spilling AS | Construction | 2012 |
| Snor AS | Construction | 2009 |
| Softdash AS | Information & communication | 2014 |
| Solstrand Camping SA | Hospitality | 1963 |
| Spangereid Auto AS | Manufacturing | 2021 |
| Spangereid Bensin & Handel AS | Hospitality | 2025 |
| Spangereid Bygg AS | Construction | 2012 |
| Spangereid Camping AS | Hospitality | 2008 |
| Spangereid Elektro AS | Construction | 2014 |
| Spangereid Grendehus SA | Real estate | 1995 |
| Spangereid Naturbarnehage AS | Education | 2012 |
| Spangereid Sauelag SA | Agriculture & fishing | 2009 |
| Spangereid Sentrum AS | Real estate | 2008 |
| Spangereid Varesenter AS | Real estate | 2022 |
| Spangereidgruppen AS | Real estate | 2006 |
| Specto AS | Health & social care | 1996 |
| SRL Holding AS | Construction | 2005 |
| SSJ Invest AS | Construction | 2012 |
| Sssg Prosjekt Holding AS | Real estate | 2018 |
| Steinsland Gård 404/9 Da | Agriculture & fishing | 2018 |
| Strai Kjøkken Lindesnes AS | Wholesale & retail | 2012 |
| Studio Roland AS | Real estate | 2015 |
| Styrestrøm AS | Wholesale & retail | 2025 |
| Støle Bygg Da | Real estate | 1999 |
| Støle Gård AS | Agriculture & fishing | 2025 |
| Størksen Fisk AS | Agriculture & fishing | 2021 |
| Sundstøl Holding AS | Other services | 2021 |
| Svein Lande Holding AS | Real estate | 2005 |
| Svennevik Bygg AS | Real estate | 2019 |
| Svennevik Eiendom AS | Administrative & support | 2001 |
| Svennevik Malerfirma AS | Administrative & support | 2012 |
| Svennvik Malerfirma Da | Administrative & support | 2010 |
| Svinstad Bygg AS | Construction | 2021 |
| Sydspissen Budservice Da | Transport & logistics | 2003 |
| Sør Sveis Røsstad AS | Manufacturing | 2007 |
| Sør-Eiendom AS | Real estate | 2008 |
| Sør-Invest AS | | 2005 |
| Sørlandet Fjordferien AS | Administrative & support | 2026 |
| Sørlands Plast AS | Wholesale & retail | 2013 |
| Sørlands Stein AS | Manufacturing | 2004 |
| Sørlands Stein Eiendom AS | Manufacturing | 1985 |
| Sørlandsfugl Oppdrett/Import Ans | Agriculture & fishing | 2000 |
| Sørlandspukk AS | Mining & quarrying | 2007 |
| Sørnorsk Eiendom AS | Real estate | 2013 |
| Sørvest Engineering AS | Construction | 2006 |
| T&H Invest AS | | 2024 |
| T.E.Olsen Holding AS | | 2025 |
| Tannteknikk Sørlandet AS | Manufacturing | 2013 |
| Taretv AS | Information & communication | 2012 |
| Team Forever AS | Wholesale & retail | 2014 |
| Terje Ariansen AS | Real estate | 2005 |
| Thinvest AS | | 2025 |
| Ti-Co AS | Financial services | 2005 |
| Tjøms Trafikkskole AS | Education | 2020 |
| TK Bygg Og Hage AS | Administrative & support | 2022 |
| Tonova AS | Construction | 2005 |
| Tor Sigurd Olsen AS | Construction | 1990 |
| Torsvik AS | Agriculture & fishing | 2010 |
| Trebo Bygg Og Transport AS | Construction | 1995 |
| Tredal AS | Manufacturing | 1987 |
| Tredal Eiendom AS | Real estate | 2013 |
| Tredal Holding AS | Manufacturing | 2013 |
| Tredaltunet AS | Health & social care | 2022 |
| Trening Sør AS | Education | 2020 |
| Trygg Trefelling Og Vedlikehold AS | Agriculture & fishing | 2025 |
| Tuinder-Service AS | Manufacturing | 2025 |
| Tørresen Bygg AS | Construction | 2016 |
| Udland Mat Og Drikke AS | Hospitality | 2004 |
| Uinvest AS | Real estate | 2005 |
| Under Restaurant AS | Hospitality | 2020 |
| Utleieferie AS | Hospitality | 1997 |
| Vaage Web AS | Information & communication | 2021 |
| Vaagen Kafé Og Interiør AS | Hospitality | 2023 |
| Valle Eiendom AS | Real estate | 2008 |
| Vannverk-Feland 1 SA | Water & waste | 2001 |
| Varmetap.No AS | Professional & scientific | 2018 |
| Velforetak Bygg 2 På Ramsland 22 SA | Real estate | 2024 |
| Vertice Invest AS | Financial services | 2018 |
| Vigeland Betong AS | Construction | 2012 |
| Vigeland Bil AS | Other services | 1998 |
| Vigeland Bil Eiendomsinvest AS | Other services | 2015 |
| Vigeland Bil Invest AS | Other services | 2015 |
| Vigeland Bygg AS | Construction | 2019 |
| Vigeland Bygg Eiendom AS | Real estate | 2002 |